Genome profiling is an efficient tool to avoid the STUMP classification of uterine smooth muscle lesions: a comprehensive array-genomic hybridization analysis of 77 tumors

Challenges of a tailored immunohistochemistry algorithm for uterine leiomyosarcoma: an integrated analysis of leiomyomas with bizarre nuclei and fumarate hydratase (FH) deficiency

AIMS

Leiomyomas (LM) are the most common uterine mesenchymal neoplasms and encompass a variety of histological subtypes. Bizarre nuclei are described in both leiomyomas with bizarre nuclei (LM-BN) and fumarate hydratase-deficient leiomyomas (FH-LM), which raise diagnostic concerns regarding leiomyosarcoma (LMS). Recently, an immunohistochemical algorithm to support the diagnosis of LMS based on the genomic landscape of these neoplasms was proposed. This study aimed to evaluate the algorithm's accuracy in distinguishing LM-BN and FH-LM from LMS.

METHODS AND RESULTS

We collected 68 LM (29 LM-BN, 30 FH-LM, and 9 LM) and 9 LMS, along with clinicopathological and molecular data. An immunohistochemical panel comprising p53, Rb, PTEN, ATRX, DAXX, and MDM2 was applied. Nine cases were non-interpretable due to fixation issues. The algorithm demonstrated 100% accuracy for LM without bizarre nuclei (9/9) and for nonmyxoid LMS (5/5). Notably, 28.6% (14/49) of LM-BN and FH-LM exhibited at least two abnormalities, leading to potential misclassification as LMS. However, their clinical course, morphology, and genomic profile supported a benign diagnosis. Frequent alterations included Rb (20/49; 40.8%) and p53 (19/49; 38.8%), particularly in bizarre cells, while no abnormal staining was observed for ATRX, DAXX, or MDM2.

CONCLUSION

The proposed algorithm has limitations in differentiating LMS from LM-BN and FH-LM, misclassifying 28.6% of the latter. Accurate interpretation requires proper internal controls, particularly for markers whose loss of expression favours malignancy. Morphology remains central for diagnosis, although integration of molecular data may provide additional insights for a definitive classification in challenging cases.

Fertility-sparing approach for uterine smooth muscle tumors of uncertain malignant potential

OBJECTIVE

Uterine smooth muscle tumors of uncertain malignant potential (STUMP) are a category of tumors that present diagnostic/therapeutic challenges since they cannot be assigned to either a benign or a malignant entity. Hysterectomy is the mainstay of treatment of STUMP. However, in most cases, STUMPs represent an incidental diagnosis following myomectomy. The optimal management of young women having an incidental diagnosis of STUMP following myomectomy is unclear. Only a few experiences are reported. This review focuses on the fertility-sparing treatment of STUMPs.

METHODS

This is a systematic review of studies comparing outcomes of patients undergoing hysterectomy and myomectomy. For this review, we included studies reporting outcomes of patients with STUMPs undergoing myomectomy. Studies reporting data only on radical treatment for STUMPs or focusing on conservative management of other uterine malignancies (including leiomyosarcoma) were excluded.

RESULTS

Pooled data of 327 patients (from 9 retrospective studies) were evaluated. Overall, the study included 159 (48.6%) and 168 (51.4%) patients who had myomectomy and hysterectomy, respectively. No differences in recurrence rates were observed after myomectomy and hysterectomy (13.2% vs 9.5%, OR 0.69, 95% CI 0.35 to 1.38, p = .30), after a median follow-up of 44 and 48 months, respectively. Patients treated with myomectomy were more likely to develop STUMP recurrences than patients treated with hysterectomy (11.9% vs 4.1%, OR 2.38, 95% CI 1.04 to 5.44, p = .046). Among 103 patients desiring to conceive, 40 (38.8%) patients achieved at least 1 pregnancy. Pregnancy was not associated with an increased risk of recurrence.

CONCLUSIONS

These cumulative data suggest that myomectomy might be considered a safe and effective alternative for women who wish to preserve their childbearing potential. Centralization, pathology review based on clinic-pathologic and molecular integration, and multidisciplinary discussion in referral centers are of paramount importance. Multicenter prospective registries are needed.

The MEF2D::NCOA2 Fusion Defines a Distinct Emerging Vulvovaginal Myxoid Epithelioid Tumor With Smooth Muscle Differentiation

Myocyte-specific enhancer factor 2D gene and nuclear receptor coactivator 2 gene fusion (MEF2D::NCOA2) was recently reported in 2 vulvovaginal myxoid epithelioid smooth muscle tumors. We aimed to perform an integrated approach combining clinical, morphologic, immunohistochemical, and molecular profiling analyses, including targeted RNA sequencing, targeted gene expression analysis profiling with clustering, DNA mutational analysis, and array comparative genomic hybridization in a series of 3 MEF2D::NCOA2 fusion-associated vulvovaginal tumors, to better describe this entity. The median age at diagnosis was 45 years. Tumors were well circumscribed and located deeply within the vulva, vaginal wall, or between the bladder and the vagina (1/3, 33.3% each). The median size of tumors was 2.5 cm. All tumors had a similar morphology, reminiscent of smooth muscle tumor with prominent myxoid stromal changes (3/3, 100%). Tumor cells were haphazardly arranged in short fascicles and were mostly spindle cells. Microcystic spaces lined by epithelioid cells and/or sheets of epithelioid cells were observed in all tumors (3/3, 100%), associated with a myxoid background. Cytologic atypia was none to mild, and the mitotic counts were always low (≤1 mitosis/high-power fields). Immunohistochemistry found smooth muscle actin, desmin, h-caldesmon, estrogen receptors, and CD34 to be intensely and diffusely expressed in all tumors (3/3, 100%). A MEF2D::NCOA2 transcript was observed in all tumors (3/3, 100%), which was the driver of molecular alteration. No pathogenic variants were found, and array comparative genomic hybridization found simple genomic profiles for all tumors (3/3, 100%). On targeted gene expression analysis, MEF2D::NCOA2 fusion-associated tumors clustered distinctly from other gynecologic mimickers and neoplasms with myxoid stromal changes (vulvovaginal leiomyomas, myxoid vulvovaginal leiomyomas, deep angiomyxomas, myxoid leiomyosarcomas, myxoid endometrial stromal sarcomas, and inflammatory myofibroblastic tumors). The signaling pathways involved in this entity included the expression of genes encoding smooth muscle phenotype proteins, favoring a smooth muscle (myoid) differentiation. All patients were alive and free of disease at the last follow-up. To conclude, vulvovaginal MEF2D::NCOA2 fusion-associated tumors are distinct and emerging entities, with a rather indolent behavior.

Genomic characterization and histologic analysis of uterine leiomyosarcoma arising from leiomyoma with bizarre nuclei

Leiomyoma with bizarre nuclei (LM-BN) is a rare variant of leiomyoma with a benign clinical course. In contrast, leiomyosarcoma (LMS) is a high-grade, malignant neoplasm characterized by high recurrence rates and poor survival. While LM-BN and LMS show distinct morphologies, they share similar immunoprofiles and molecular alterations, with both considered 'genomically unstable'. Rare cases of LM-BN associated with LMS have been reported; however, the histogenesis and molecular relationship between these two tumors remains unclear. In this study, we assessed 11 cases of LMS arising in conjunction with LM-BN confirmed by histology and immunohistochemistry (IHC), further analyzed by clinical, histologic, and molecular characteristics of these distinct components. LM-BN and LMS had similar p16 and p53 IHC patterns, but LMS had a higher Ki-67 index and lower estrogen and progesterone eceptor expression. Digital image analysis based on cytologic features revealed spatial relationships between LMS and LM-BN. Genomic copy number alterations (CNAs) demonstrated the same clonal origin of LMS arising from existing LM-BN through conserved CNAs. LMS harbored highly complex CNAs and more frequent losses of the TP53, RB1, and PTEN genomic regions than LM-BN (p = 0.0031), with CDKN2A/B deletion identified in LMS only. Mutational profiling revealed many shared oncogenic alterations in both LM-BN and LMS; however, additional mutations were present within LMS, indicative of tumor progression through progressive genomic instability. Analysis of spatial transcriptomes defined uniquely expressed gene signatures that matched the geographic distribution of LM-BN, LMS, and other cell types. Our findings indicate for the first time that a subset of LMS arises from an existing LM-BN, and highly complex genomic alterations could be potential high risks associated with disease progression in LM-BN. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

The Morphologic and Molecular Heterogeneity of Fumarate Hydratase-deficient Leiomyomas: Integrative Molecular Profiling of Uterine Smooth Muscle Tumors With Histologic Feature Correlation

The morphologic features of uterine smooth muscle tumors (USMTs) are subject to interobserver variability and are complicated by consideration of features of fumarate hydratase deficiency (FHd) and other morphologic subtypes, with difficult cases occasionally diagnosed as smooth muscle tumor of uncertain malignant potential (STUMP). We compare immunohistochemical findings and detailed morphologic analysis of 45 USMTs by 4 fellowship-trained gynecologic pathologists with comprehensive molecular analysis, focusing on FHd leiomyomas (n=15), compared to a variety of other USMTs with overlapping morphologic features, including 9 STUMPs, 8 usual-type leiomyomas (ULM), 11 apoplectic leiomyomas, and 2 leiomyomas with bizarre nuclei (LMBN). FHd leiomyomas, defined by immunohistochemical (IHC) loss of FH and/or 2SC accumulation, showed FH mutations and/or FH copy loss in all cases, with concurrent TP53 mutations in 2 tumors. Severe and/or symplastic-type cytologic atypia was seen more often in FHd leiomyomas with only FH copy loss (6/8, and 2/2 with concurrent TP53 mutations) compared to those with FH mutations (2/7) and typically showed increased genomic instability. This subset of FHd tumors often showed morphologic overlap with STUMPs and LMBN, but all cases of FHd tumors showed 2SC accumulation and/or FH loss by IHC. In conclusion, we highlight the importance of investigating USMTs with severe and/or symplastic-type cytologic atypia with FH and 2SC IHC, as many of these tumors are FH-deficient via focal deep deletion (2-copy loss) of the FH locus. In addition, we report the presence of concurrent TP53 mutations in FHd tumors with more severe cytologic atypia; further data about clinical outcomes for these tumors are needed.

Risk Stratification of Uterine Smooth Muscle Tumors: The Role of Morphology, Immunohistochemistry, and Molecular Testing

Uterine smooth muscle neoplasms are a biologically and clinically heterogeneous group of tumors. Morphology is the cornerstone of pathologic diagnosis of these tumors, and most are readily classified as benign or malignant on the basis of routine histologic examination. However, rare subsets-including intravenous leiomyomatosis, benign metastasizing leiomyoma, and disseminated peritoneal leiomyomatosis-have a capacity for extrauterine spread despite benign cytomorphology. A further subset of uterine smooth muscle neoplasms, termed "smooth muscle tumor of uncertain malignant potential (STUMP)," are not readily classified as benign or malignant and carry an intermediate prognosis. STUMP is a protean category, whose precise definition is subject to disagreement among experts. The risk profiles of different STUMP morphotypes remain largely unresolved. Finally, multiple morphology-based systems for risk stratification of uterine leiomyosarcoma have been proposed, though none is widely adopted. Immunohistochemical and molecular prognostic markers for both STUMP and leiomyosarcoma remain in the early phases of adoption in routine diagnostic practice.

First Case Report of Uterine Leiomyosarcoma Diagnosed After Transcervical Fibroid Ablation

Background: Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common female pelvic neoplasms globally. Treatments may be invasive, such as hysterectomy and myomectomy, non-invasive, such as medical therapy or focused ultrasound, or minimally invasive, such as transcervical radiofrequency ablation (TFA). To date, more than 12,000 women have been treated worldwide using TFA with the Sonata® System. Case Presentation: We present the first case report of TFA on a presumptive fibroid that was initially reclassified as a STUMP (smooth muscle tumor of uncertain malignant potential) and, after additional surgical treatment, leiomyosarcoma. Conclusion: This case highlights that, while uterine sarcoma is rare, inadvertent treatment may still result due to a lack of reliable diagnostic modalities. Nonetheless, TFA with the Sonata System represents a minimally invasive option that might not alter the prognosis of an undiagnosed uterine sarcoma as this treatment is not intraperitoneal and does not resect/morcellate tissue.

In Vitro Effect of Estrogen and Progesterone on Cytogenetic Profile of Uterine Leiomyomas

In the present study, we aimed to investigate intratumoral karyotype diversity as well as the estrogen/progesterone effect on the cytogenetic profile of uterine leiomyomas (ULs). A total of 15 UL samples obtained from 15 patients were cultured in the media supplemented with estrogen and/or progesterone and without adding hormones. Conventional cytogenetic analysis of culture samples revealed clonal chromosomal abnormalities in 11 out of 15 ULs. Cytogenetic findings were presented by simple and complex chromosomal rearrangements (64% and 36% of cases, respectively) verified through FISH and aCGH. In most ULs with complex chromosomal rearrangements, the breakpoints did not feature clusterization on a single chromosome but were evenly distributed across rearranged chromosomes. The number of breakpoints showed a strong positive correlation with the number of rearranged chromosomes. Moreover, both abovementioned parameters were in a linear dependency from the number of karyotypically different clones per UL. This suggests that complex chromosomal rearrangements in ULs predominantly originate through sequential events rather than one hit. The results of UL cytogenetic analysis depended on the presence of estrogen and/or progesterone in the culture medium. The greatest variety of cytogenetically different cell clones was detected in the samples cultured without hormone supplementation. Their counterparts cultured with progesterone supplementation showed a sharp decrease in clone number, whereas such a decrease induced by estrogen or estrogen-progesterone supplementation was insignificant. These findings suggest that estrogen-progesterone balance is crucial for forming a UL cytogenetic profile, which, in turn, may underlie the unique response of the every karyotypically abnormal UL to medications.

Uterine smooth muscle tumors of uncertain malignant potential: a 13-year retrospective study

Objective

The primary objective of this study was to provide valuable evidence for the management of patients diagnosed with uterine smooth muscle tumors of uncertain malignant potential (STUMP), with a focus on those with reproductive aspirations.

Methods

We conducted a retrospective analysis of clinical and pathological data from the medical records and slides of STUMP patients treated at Drum Tower Hospital, affiliated with Nanjing University Medical School, from January 2009 to December 2021.

Results

Thirty-four patients were included in the study, with a median follow-up duration of 76 months (range: 13-157 months). After slide review, the diagnosis agreement rate was 77.3% (34/44 among initially considered cases). The consistency rate between our hospital's diagnosis and those of other institutions was 75% (15/20). The accuracy rate of intraoperative frozen section diagnosis was low, at 21.4% (3/14). Half of the patients (17) underwent myomectomy, while the other half (17) received hysterectomy, including one subtotal hysterectomy. Two recurrences were observed (5.9%), one as STUMP and the other as leiomyosarcoma, with one recurrence in each surgical group. Notably, 4 of 9 patients with reproductive aspirations successfully underwent cesarean deliveries. Patients with single lesions appeared to exhibit potentially favorable fertility outcomes compared to those with multiple lesions.

Conclusion

The diagnosis of STUMP was difficult. Myomectomy potentially could serve as an alternative for patients with reproductive needs. In selected cases with single lesions, it may indicate potentially favorable fertility outcomes.

Uterine Leiomyosarcoma With Osteoclast-like Giant Cells: Report of 2 Cases and Review of Literature

Leiomyosarcoma (LMS) with osteoclast-like giant cells (OLGCs) is a rare entity with only 18 reported cases thus far. It is not known whether these OLGCs are a reactive or malignant component of LMS. Herein we describe the clinical, histologic, and molecular characteristics of 2 cases of LMS with OLGCs and perform a brief literature review. In 2 of our cases, the OLGCs, marked with CD68, had a low proliferation index with Ki67 and did not show diffuse positivity for smooth muscle markers by immunohistochemistry. By next-generation sequencing, one case harbored a clinically significant TP53 mutation, which has been reported in a significant subset of conventional LMSs. In this case, based on immunohistochemistry, OLGCs showed different molecular alterations as compared with LMS. Although we did not show a distinct immunophenotype or molecular profile for LMS with OLGCs, this study provides additional data on this rare entity.

Genomic profile analysis of leiomyomas with bizarre nuclei and fumarate hydratase deficient leiomyomas: Strengths, weaknesses, and limitations of array-CGH interpretation

A close relationship has been demonstrated between genomic complexity and clinical outcome in uterine smooth muscle tumors. We studied the genomic profiles by array-CGH of 28 fumarate hydratase deficient leiomyomas and 37 leiomyomas with bizarre nuclei (LMBN) from 64 patients. Follow-up was available for 46 patients (from three to 249 months, mean 87.3 months). All patients were alive without evidence of disease. For 51 array-CGH interpretable tumors the mean Genomic Index (GI) was 16.4 (median: 9.8; from 1 to 57.8), significantly lower than the mean GI in LMS (mean GI 51.8, p < 0.001). We described three groups: (1) a group with FH deletion (24/58) with low GI (mean GI: 11 vs. 22,4, p = 0.02), (2) a group with TP53 deletion (17/58) with higher GI (22.4 vs. 11 p = 0.02), and (3) a group without genomic events on FH or TP53 genes (17/58) (mean GI:18.3; from 1 to 57.8). Because none of these tumors recurred and none showed morphological features of LMS we concluded that GI at the cut-off of 10 was not applicable in these subtypes of LM. By integration of all those findings, a GI <10 in LMBN remains a valuable argument for benignity. Conversely, in LMBN a GI >10 or alteration in tumor suppressor genes, should not alone warrant a diagnosis of malignancy. Nine tumors were tested with Nanocind CINSARC® signature and all were classified in low risk of recurrence. We propose, based on our observations, a diagnostic approach of these challenging lesions.

[Diagnosis of uterine sarcomas and rare uterine mesenchymal tumours with malignant potential. Guidelines of the French Sarcoma Group and Rare Gynaecological Tumours]

The landscape of uterine sarcomas is becoming more complex with the description of new entities associated with recurrent driver molecular alterations. Uterine sarcomas, in analogy with soft tissue sarcomas, are distinguished into complex genomic and simple genomic sarcomas. Leiomyosarcomas and undifferentiated uterine sarcomas belong to complex genomic sarcomas group. Low-grade and high-grade endometrial stromal sarcomas, other rare tumors associated with fusion transcripts (such as NTRK, PDGFB, ALK, RET ROS1) and SMARCA4-deficient uterine sarcoma are considered simple genomic sarcomas. The most common uterine sarcoma are first leiomyosarcoma and secondly endometrial stromal sarcomas. Three different histological subtypes of leiomyosarcoma (fusiform, myxoid, epithelioid) are identified, myxoid and epithelioid leiomyosarcoma being more aggressive than fusiform leiomyosarcoma. The distinction between low-grade and high-grade endometrial stromal sarcoma is primarily morphological and immunohistochemical and the detection of fusion transcripts can help the diagnosis. Uterine PEComa is a rare tumor, which is distinguished into borderline and malignant, according to a risk assessment algorithm. Embryonal rhabdomyosarcoma of the uterine cervix is more common in children but can also occur in adult women. Embryonal rhabdomyosarcoma of the uterine cervix is almost always DICER1 mutated, unlike that of the vagina which is wild-type DICER1, and adenosarcoma which can be DICER1 mutated but with less frequency. Among the emerging entities, sarcomas associated with fusion transcripts involving the NTRK, ALK, PDGFB genes benefit from targeted therapy. The integration of molecular data with histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

The KAT6B::KANSL1 Fusion Defines a New Uterine Sarcoma With Hybrid Endometrial Stromal Tumor and Smooth Muscle Tumor Features

Neoplasms harboring a KAT6B/A::KANSL1 fusion were initially reported as benign (leiomyomas) and malignant (leiomyosarcomas, low-grade endometrial stromal sarcomas [LG-ESSs]) uterine neoplasms. However, they may represent an emerging entity characterized by clinical aggressiveness contrasting with a rather reassuring microscopic appearance. Here, we aimed to confirm that this neoplasm is a distinct clinicopathologic and molecular sarcoma and identify criteria that should alert pathologists and lead to KAT6B/A::KANSL1 fusion testing in routine practice. Therefore, we conducted a comprehensive clinical, histopathologic, immunohistochemical, and molecular study, including array comparative genomic hybridization, whole RNA-sequencing, unsupervised clustering, and cDNA mutational profile analyses of 16 tumors with KAT6B::KANSL1 fusion from 12 patients. At presentation, patients were peri-menopausal (median, 47.5 years), and the primary tumors were located in the uterine corpus (12/12, 100%), with an additional prevesical location in 1 (8.3%) of 12 cases. The relapse rate was 33.3% (3/9). All tumors (16/16, 100%) showed morphologic and immunohistochemical features overlapping between leiomyoma and endometrial stromal tumors. A whirling recurrent architecture (resembling fibromyxoid-ESS/fibrosarcoma) was found in 13 (81.3%) of 16 tumors. All tumors (16/16, 100%) exhibited numerous arterioliform vessels, and 13 (81.3%) of 18 had large hyalinized central vessels and collagen deposits. Estrogen and progesterone receptors were expressed in 16 (100%) of 16 and 14 (87.5%) of 16 tumors, respectively. Array comparative genomic hybridization performed on 10 tumors classified these neoplasms as simple genomic sarcomas. Whole RNA-sequencing on 16 samples and clustering analysis on primary tumors found that the KAT6B::KANSL1 fusion always occurred between exons 3 of KAT6B and 11 of KANSL1; no pathogenic variant was identified on cDNA, all neoplasms clustered together, close to LG-ESS, and pathway enrichment analysis showed cell proliferation and immune infiltrate recruitment pathway involvement. These results confirm that the sarcomas harboring a KAT6B/A::KANSL1 fusion represent a distinct clinicopathologic entity, close to LG-ESS but different, with clinical aggressiveness despite a reassuring morphology, for which the KAT6B/A::KANSL1 fusion is the molecular driver alteration.

[Uterine leiomyosarcoma - French guidelines from the GSF/NETSARC and TMRG groups]

Uterine leiomyosarcomas represent the most common uterine sarcomas. The prognosis is poor with metastatic recurrence in more than half of the cases. The purpose of this review is to make French recommendations for the management of uterine leiomyosarcomas within the framework of the French Sarcoma Group - Bone Tumor Study Group (GSF-GETO)/NETSARC+ and Malignant Rare Gynecological Tumors (TMRG) networks in order to optimize their therapeutic management. The initial assessment includes a MRI with diffusion perfusion sequence. The diagnosis is histological with a review in an expert center (Reference Network in Sarcoma Pathology (RRePS)). Total hysterectomy with bilateral salpingectomy, en bloc without morcellation, is performed when complete resection is possible, whatever the stage. There is no indication of systematic lymph node dissection. Bilateral oophorectomy is indicated in peri-menopausal or menopausal women. Adjuvant external radiotherapy is not a standard. Adjuvant chemotherapy is not a standard. It can be an option and consists in doxorobucin based protocols. In the event of local recurrence, the therapeutic options are based on revision surgery and/or radiotherapy. Systemic treatment with chemotherapy is most often indicated. In case of metastatic disease, surgical treatment remains indicated when resecable. In cases of oligo-metastatic disease, focal treatment of metastases should be considered. In the case of stage IV, chemotherapy is indicated, and is based on first-line doxorubicin-based protocols. In the event of excessive deterioration in general condition, management by exclusive supportive care is recommended. External palliative radiotherapy can be proposed for symptomatic purposes.

Percutaneous Uterine Needle Biopsy with Microscopic and Array-CGH Analyses for Preoperative Sarcoma Diagnosis in Patients with Suspicious Myometrial Tumors on MRI: A Prospective Pilot Study (SARCGYN)

BACKGROUND

Unlike for soft tissue sarcomas, percutaneous biopsy is not validated for uterine myometrial tumors, leading to leiomyosarcoma inadvertent morcellation and overtreatment in childbearing patients. This study aimed to evaluate preoperative percutaneous uterine needle biopsy (PUB) with microscopic examination (M-PUB) and array-comparative genomic hybridization (MCGH-PUB).

METHODS

This was a prospective single-center cohort study including all consecutive patients who were candidates for hysterectomy because of suspected uterine leiomyosarcoma on magnetic resonance imaging (MRI) who received PUB. Microscopic and array-CGH analyses with genomic index (GI) counts were performed to guide the therapeutic strategy. Smooth-muscle tumors with suspect features with a GI above 15 were deemed malignant, as were tumors without microscopic malignant features with a complex genomic profile (GI above 30 or malignant profile). Preoperative diagnoses based on M-PUB and MCGH-PUB were compared with the postsurgical pathological specimen or follow-up.

RESULTS

From November 2016 to February 2022, 34 patients were included. Based on the surgical specimen (N = 23) or follow-up (N = 11), final diagnoses were 11 sarcomas and 23 non-sarcomas. The median follow-up was 12 months (IQR 6-37). The diagnostic accuracies of M-PUB and MCGH-PUB were 94% and 100%, respectively. The sensitivity, specificity, and negative predictive value of MCGH-PUB were 100%, 100%, and 100%, respectively. A high GI was significantly associated with malignancy (P < 0.001). Genomic analyses allowed malignancy upgrades for four tumors. There were no complications and no dissemination along the biopsy track.

CONCLUSION

MCGH-PUB is safe and accurate for preoperatively diagnosing uterine sarcomas and should be used routinely after suspicious MRI to tailor surgery.

Primary Retroperitoneal Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP): A Diagnostic Enigma

Retroperitoneal sarcomas represent a group of rare malignant neoplasms with complex clinical management and often a poor prognosis. An elderly male presented with a slowly progressive, right-sided abdominal lump for four months associated with loss of appetite and abdominal discomfort. Abdominal examination revealed an apparent retroperitoneal lump in the right lumbar and umbilical region, which was well-defined, and firm in consistency with the bosselated surface. Contrast-enhanced computed tomography (CECT) of the abdomen and pelvis revealed a heterogenous lobulated malignant appearing retroperitoneal lesion arising from the right anterior perirenal space with a differential of retroperitoneal sarcoma. Wide local excision of the tumor was done. Histopathology of the lesion revealed a smooth muscle tumor of uncertain malignant potential (STUMP). The patient is asymptomatic and recurrence-free after 24 months of follow-up.

An Extremely Rare Case of Disseminated Peritoneal Leiomyomatosis with a Pelvic Leiomyosarcoma and Omental Metastasis after Laparoscopic Morcellation: Systematic Review of the Literature

Minimally invasive treatment of uterine fibroids usually requires a power morcellation, which could be associated with several complications. A rare sequela is disseminated peritoneal leiomyomatosis. Indeed, recurrence or metastasis in these cases could be attributed to iatrogenic or under-evaluation of primary tumors, although a subset of cases is a sporadic sample of biological progression. We present an extremely rare case of a patient who underwent laparoscopic morcellation and after 12 years developed a pelvic leiomyosarcoma with two omental metastases, disseminated peritoneal leiomyomatosis with a parasite leiomyoma with bizarre nuclei and a parasite cellular leiomyoma simultaneously. The diagnosis was predicted preoperatively by an expert sonographer who recognized the ultrasound characteristics of uterine sarcoma and the localization of some of the masses, so the patient was referred to the gynaecological oncologists who could appropriately treat her. We present here a case report and a systematic review that could be a useful tool for further discussion and future clinical practice guidelines.

Uterine sarcomas and rare uterine mesenchymal tumors with malignant potential. Diagnostic guidelines of the French Sarcoma Group and the Rare Gynecological Tumors Group

The landscape of uterine sarcomas is becoming increasingly complex with the description of new entities associated with recurrent molecular alterations. Uterine sarcomas, as well as soft tissue sarcomas, can be distinguished into complex genomic sarcomas and simple genomic sarcomas. Leiomyosarcoma and pleomorphic type undifferentiated uterine sarcoma belong to the first group. Low-grade and high-grade endometrial stromal sarcomas, NTRK, COL1A1::PDGFB, ALK, RET, ROS1 associated sarcomas, and SMARCA4 deficient uterine sarcoma belong to the second group. Leiomyosarcoma is the most common uterine sarcoma followed by endometrial stromal sarcomas. Three different histologic subtypes of leiomyosarcomas are recognized with distinct diagnostic criteria and different clinical outcomes, the myxoid and epithelioid leiomyosarcomas being even more aggressive than the fusiform type. The distinction between low-grade and high-grade endometrial stromal sarcoma is based first on morphology and immunohistochemistry. The detection of fusion transcripts helps in the diagnosis. Definitely recognized as a separate entity, uterine PEComa is a rare tumor whose diagnostic criteria are being recently defined. Uterine PEComa has a specific algorithm stratifying the tumors into uncertain malignant potential and malignant tumors. Embryonal rhabdomyosarcomas of the uterine cervix are not restricted to children but can also be observed in adult women and are almost always DICER1 mutated, unlike embryonal rhabdomyosarcoma of the vagina which are DICER1wild-type, and adenosarcoma which can be DICER1 mutated but with less frequency. As sarcomas associated with fusion transcripts involving the NTRK, ALK, COL1A1::PDGFB genes can benefit from targeted therapy, systematic detection are now relevant especially for patients with high risk of relapse or in recurrent setting. The integration of molecular data with dedicated expert pathology review for histology and clinical data allows better identification of uterine sarcomas in order to better treat them.

Clinical and Histopathological Predictors of Recurrence in Uterine Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP): A Multicenter Retrospective Cohort Study of Tertiary Centers

BACKGROUND

The term uterine smooth muscle tumor of uncertain malignant potential (STUMP) indicates a rare, equivocal entity between benign leiomyomas and leiomyosarcomas. In the present study, we evaluated a comprehensive range of clinical, surgical, and pathological features in a large multicenter series of patients with STUMP to identify risk factors for recurrence.

METHODS

This is a retrospective study performed by collecting consecutive cases diagnosed between January 2000 and December 2020 in five tertiary centers. Associations between STUMP recurrence and clinicopathological characteristics as well as surgical treatment modality were investigated.

RESULTS

Eighty-seven patients affected by STUMP were considered. Of them, 18 cases (20.7%) recurred: 11 as leiomyosarcoma (LMS) and 7 as STUMP. The mean time to recurrence was 79 months. We found that fragmentation/morcellation, epithelioid features, high mitotic count, Ki-67 value > 20%, progesterone receptor (PR) < 83%, and p16 diffuse expression were associated with higher risk of recurrence and shorter recurrence-free survival (RFS). Furthermore, morcellation/fragmentation and mitotic count remained independent risk factors for recurrence and shorter RFS after multivariate analysis, while the presence of epithelioid features was an independent risk factor for recurrence only.

CONCLUSIONS

Our results suggest that morcellation is associated with risk of recurrence and shorter RFS, thus it should be avoided if a STUMP is suspected preoperatively. Epithelioid features, high proliferation activity, low PR expression, and diffuse p16 expression are also unfavorable prognostic factors, so patients presenting these features should be closely followed up.

CINSARC in high-risk soft tissue sarcoma patients treated with neoadjuvant chemotherapy: Results from the ISG-STS 1001 study

BACKGROUND

The Complexity INdex in SARComas (CINSARC) is a transcriptional signature derived from the expression of 67 genes involved in mitosis control and chromosome integrity. This study aims to assess CINSARC value of in an independent series of high-risk patients with localized soft tissue sarcoma (STS) treated with preoperative chemotherapy within a prospective, randomized, phase III study (ISG-STS 1001).

PATIENTS AND METHODS

Patients with available pre-treatment samples, treated with 3 cycles of either standard (ST) preoperative or histotype-tailored (HT) chemotherapy, were scored according to CINSARC (low-risk, C1; high-risk, C2). The 10-year overall survival probability (pr-OS) according to SARCULATOR was calculated, and patients were classified accordingly (low-risk, Sarc-LR, 10-year pr-OS>60%; high-risk, Sarc-HR, 10-year pr-OS<60%). Survival functions were estimated using the Kaplan-Meier method and compared using log-rank test.

RESULTS

Eighty-six patients were included, 30 C1 and 56 C2, 49 Sarc-LR and 37 Sarc-HR. A low level of agreement between CINSARC and SARCULATOR was observed (Cohen's Kappa = 0.174). The 5-year relapse-free survival in C1 and C2 were 0.57 and 0.55 (p = 0.481); 5-year metastases-free survival 0.63 and 0.64 (p = 0.740); 5-year OS 0.80 and 0.72 (p = 0.460). The 5-year OS in C1 treated with ST and HT chemotherapy was 0.84 and 0.76 (p = 0.251) respectively; in C2 treated it was 0.72 and 0.70 (p = 0.349). The 5-year OS in Sarc-LR treated with S and HT chemotherapy was 0.80 and 0.82 (p = 0.502) respectively; in Sarc-HR it was 0.70 and 0.61 (p = 0.233).

CONCLUSIONS

Our results, although constrained by the small size of the series, suggest that CINSARC has weak prognostic power in high-risk, localized STS treated with neoadjuvant chemotherapy.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

p53, p16 and ki67 as immunohistochemical prognostic markers in uterine smooth muscle tumors of uncertain malignant potential (STUMP)

The risk stratification in gynecologic smooth muscle tumors of uncertain malignant potential (STUMP) is a crucial issue, but at present there are no validated prognostic markers. We aimed to assess p53, p16 and ki67 as immunohistochemical prognostic markers in STUMP through a systematic review and meta-analysis. Electronic databases were searched from their inception to July 2020. All studies assessing p53, p16 and/or ki67 immunohistochemistry in gynecologic STUMP series were included. Immunohistochemical patterns were categorized as "abnormal" vs "wild-type" for p53, "diffuse" vs "focal/negative" for p16, ≥ 10% vs 10% for ki67. The prognostic value for recurrence was assessed through Cox regression analysis; a p-value 0.05 was considered significant. Markers that resulted significant were assessed for prognostic accuracy with calculation of area under the curve (AUC) and post-test probability of recurrence. Seven studies with 171 patients were included. Significant association with disease-free survival was found for p53 (p 0.0001) and p16 (p 0.0001), but not for ki67 (p = 0.911). p53 showed sensitivity= 83%, specificity= 86%, AUC= 0.89, and post-test recurrence probabilities of 54% and 7% in the case of abnormal and wild-type expression, respectively. p16 showed sensitivity= 84%, specificity= 88%, AUC= 0.91 and post-test recurrence probabilities of 56% and 7% in the case of diffuse and focal/negative expression, respectively. In conclusion, p53 and p16 might be useful in the risk assessment of STUMP, despite not being suitable as stand-alone prognostic markers.

Uterine smooth muscle tumors of uncertain malignant potential (STUMP): A retrospective study in a single center

OBJECTIVE

Uterine smooth muscle tumors of uncertain malignant potential (STUMP) is a heterogeneous group of tumors with histological and biological diversity that cannot be defined as a benign leiomyoma or malignant leiomyosarcoma. The study aims to investigate the diagnostic methods, treatment management and prognosis of STUMP patients in a 13-year period.

STUDY DESIGN

We retrospectively reviewed the clinicopathologic information of 31 STUMP patients in Peking University People's Hospital. Statistical analyses were conducted to compare the difference of clinical characteristics between the women in myomectomy group and those in hysterectomy group.

RESULTS

The most common clinical presentation was menstrual disorder. The tumors were mainly manifested as hypoechoic, non-cystic nodules with low blood flow signal by pelvic doppler ultrasonography. Most tumors carried Ki-67 index ranging from 10% to 30%. Immunohistochemical markers such as ER, PR, p16 and Desmin was positively expressed in tumors. At the first operation, 21 cases underwent myomectomy and 10 cases underwent hysterectomy. The patients in myomectomy group were younger than those in hysterectomy group. In the follow-up period, two cases experienced a relapse in the form of STUMP within 36 months. One case died of cardiovascular accident while the other cases were alive. Six of 21 women in myomectomy group desired pregnancy and two healthy live births were recorded.

CONCLUSION

The diagnosis of STUMP primarily depends on histopathologic features. Fertility-sparing surgery may be a treatment selection for patients with fertility desire. Patients with STUMP, especially in the case of myomectomy, should be informed of recurrence risk and monitored closely.

Uterine smooth muscle tumour of uncertain malignant potential and in vitro fertilization treatment in an infertile patient

The term smooth uterine muscle of uncertain malignant potential (STUMP) indicates a group of uterine smooth muscle tumours that cannot be diagnosed unequivocally as malignant but does not fulfil the criteria for leiomyoma, or its variants. In this case, we present a woman treated for infertility who presented with an asymptomatic cervical mass, diagnosed as STUMP after three cycles of controlled ovarian stimulation. We reviewed the literature with particular emphasis on the effects of STUMP upon fertility, up-to-date guidance regarding the management of patients’ wishing fertility-sparing approaches and obstetric outcomes. To the best of our knowledge, this is the first case report of STUMP in a patient that has undergone multiple in vitro fertilization treatments as well as the first to provide a putative biological basis for the efficacy of gonadotropin-releasing hormone agonists, in this patient group.

Combination of MCM2 With Ki67 and p16 Immunohistochemistry Can Distinguish Uterine Leiomyosarcomas

Our objective was to evaluate the diagnostic utility of 2 new proliferation markers, cyclin D1 and minichromosome maintenance complex component 2 (MCM2), in comparison with p16, p53, and Ki67 in differentiating the spectrum of smooth muscle tumors. An institutional database search from 2009 to 2017 identified 10 cases of uterine leiomyoma with bizarre nuclei (LBN), 12 smooth muscle tumors of uncertain malignant potential, and 13 leiomyosarcomas (LMS). Ten resected leiomyomas (LM) were included as controls. Immunohistochemistry was performed on the befitting representative block from each case. Ki67 was <10% in all LMs and LBNs, whereas >10% in all LMSs. Although wild-type in majority of cases, p53 was overexpressed in 38% of LMSs. Cyclin D1 nuclear positivity in LMs, LBNs, and smooth muscle tumors of uncertain malignant potentials ranged from 0% to 65% of neoplastic cells with mostly weak to moderate staining intensity. Instead, cyclin D1 expression was <5% in all LMSs. The ratio of MCM2 positivity exhibited a similar wide range (<1%-80%) in LMs, LBNs, and smooth muscle tumors of uncertain malignant potentials but interestingly, 92% (12/13) of LMSs were diffusely and strongly positive for MCM2 (>80% cell positivity). Overall, for diagnosis of LMS, the sensitivity for diffuse intense MCM2 staining was higher (92%) compared with diffuse staining for p16 (77%); however, specificity of MCM2 and p16 was comparable (94% and 97%, respectively). Herein, we describe the immunohistochemical profile of 2 new proliferation markers, cyclin D1 and MCM2 in uterine smooth muscle tumors. A combination of diffuse strong MCM2 and p16 reactivity with increased Ki67 index can reliably distinguish LMSs from benign histologic mimics.

Genomic and Epigenomic Profile of Uterine Smooth Muscle Tumors of Uncertain Malignant Potential (STUMPs) Revealed Similarities and Differences with Leiomyomas and Leiomyosarcomas

Uterine smooth muscle tumors of uncertain malignant potential (STUMPs) represent a heterogeneous group of tumors that cannot be histologically diagnosed as unequivocally benign or malignant. For this reason, many authors are working to obtain a better definition of diagnostic and prognostic criteria. In this work, we analyzed the genomic and epigenomic profile of uterine smooth muscle tumors (USMTs) in order to find similarities and differences between STUMPs, leiomyosarcomas (LMSs) and leiomyomas (LMs), and possibly identify prognostic factors in this group of tumors. Array-CGH data on 23 USMTs demonstrated the presence of a more similar genomic profile between STUMPs and LMSs. Some genes, such as PRKDC and PUM2, with a potential prognostic value, were never previously associated with STUMP. The methylation data appears to be very promising, especially with regards to the divergent profile found in the sample that relapsed, characterized by an overall CGI hypomethylation. Finally, the Gene Ontology analysis highlighted some cancer genes that could play a pivotal role in the unexpected aggressive behavior that can be found in some of these tumors. These genes could prove to be prognostic markers in the future.

Uterine leiomyosarcomas with osteoclast-like giant cells associated with high expression of RUNX2 and RANKL

Uterine leiomyosarcoma (ULMS) with osteoclast-like giant cells (OLGCs) has been reported as a rare phenomenon in ULMS, and its clinico-pathological features and tumorigenesis remain unclear. We recently reported high expression of receptor activator of nuclear factor κB ligand (RANKL) in ULMS with OLGCs. As osteoblasts produce RANKL, in this study, we analyzed the expression of Runt-related transcription factor 2 (RUNX2), a critical transcription factor for osteoblasts, and osteoclast-related proteins in three cases of ULMS with OLGCs as well as five conventional ULMSs and nine leiomyomas. Immunohistochemistry and real-time reverse transcription quantitative polymerase chain reaction analyses showed high expression of RUNX2 and RANKL in ULMS with OLGCs. In these cases, macrophages expressed receptor activator of nuclear factor κB (RANK), and OLGCs expressed osteoclast-related proteins (nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), and cathepsin K). Accumulation sites of cathepsin K-positive OLGCs showed hemorrhagic appearance and degraded type IV collagen. We reviewed reported cases of ULMS with OLGCs, including ours, and found that they presented an aggressive course even at stage I. Furthermore, metastatic lesions showed similar histological features to those of OLGC association in ULMS. Here, we show that tumor cells in ULMS with OLGCs highly express RUNX2 and RANKL and that osteoclastic differentiation of macrophages occurs in the tumor tissue.

Undifferentiated and dedifferentiated neoplasms of the female genital tract

Undifferentiated neoplasms in the female gynecologic tract comprise two main groups-undifferentiated carcinoma, most common in the endometrium and ovary, and undifferentiated uterine sarcoma, although tumors with an undifferentiated appearance may occur in all gynecologic organs. Their differential diagnosis is broad and generous sampling, careful morphological evaluation, judicious use of immunohistochemistry, and in many cases, molecular testing is often essential in the diagnostic work-up. As some of these neoplasms fail to respond to conventional chemotherapy regimens and/or radiation therapy, targeted therapy may be valuable in treating these highly aggressive tumors, thus the importance of precise diagnosis. In this review we discuss the clinicopathological features of undifferentiated carcinoma, dedifferentiated carcinoma, and undifferentiated uterine sarcoma, followed by a comprehensive analysis of morphological mimickers. Finally, we briefly review ovarian and lower genital tract tumors with an undifferentiated histological appearance.

Molecular prognostication of uterine smooth muscle neoplasms: From CGH array to CINSARC signature and beyond

Uterine leiomyoma and leiomyosarcoma are located at the ends of the spectrum of smooth muscle lesions. Leiomyosarcoma belongs to the complex genomic sarcomas characterized by complex karyotypes. In contrast, leiomyoma, has a low level of chromosomal complexity. The analysis of genomic profiles of uterine smooth muscle tumors shows that genomic complexity, which is an expression of chromosomal instability, correlates with the metastatic potential and malignity of tumors: the more genetically complex a smooth muscle tumor is, the more malignant is its progression. In uterine tumors with uncertain malignant potential, the assessment of genomic index by CGH array, that is, counting the genomic complexity of a tumor, allows tumors with a risk of recurrence such as leiomyosarcomas to be distinguished from benign tumors like leiomyomas. The prognosis of leiomyosarcoma is poor and the most powerful prognostic factor so far is stage, as the histologic grade is not informative. In the quest to find efficient molecular prognostic factors, the transcriptomic signature CINSARC Nanocind, a mirror of chromosomic complexity and instability, outperforms stage, in both overall and recurrence-free survival. Genomic index and the CINSARC signature will contribute to improving diagnoses, therapeutic strategies, and randomization in future clinical trials. The biological understanding of the links between the CINSARC signature and metastatic mechanisms may lead to the development of new drugs. Furthermore, ctDNA is a promising new technique to detect residual disease and early recurrence.

NFATc2-rearranged sarcomas: clinicopathologic, molecular, and cytogenetic study of 7 cases with evidence of AGGRECAN as a novel diagnostic marker

NFATc2-rearranged sarcomas (NFATc2-Sarcomas) are infrequent round cell tumors characterized by EWSR1-NFATc2 fusions and FUS-NFATc2 fusions. Although our knowledge on these neoplasms has increased recently, novel diagnostic tools and more comprehensive series are still needed. Here, we describe the features of a series of seven molecularly confirmed NFATc2-Sarcomas (EWSR1-NFATc2, n = 4; FUS-NFATc2, n = 3) and demonstrate the utility of AGGRECAN immunohistochemistry for their identification. Patients were four males and three females, ranging in age from 19 to 66 years (median: 33). All were primary bone tumors (femur, n = 4; tibia, n = 2; ilium, n = 1), frequently infiltrating the surrounding soft tissues. Treatment often consisted of neoadjuvant chemotherapy and surgery. Follow-up was available for six patients (median 18 months, range 5-102 months), three patients died of disease and four patients are currently alive. Histologically, tumors consisted of monotonous round cells growing in lobules and sheets in variable amounts of fibrous to myxoid stroma. Other findings included spindle cells, corded and trabecular architecture, nuclear pleomorphism, cartilaginous differentiation, and osteoid-like matrix. Histological response to neoadjuvant chemotherapy was poor in all resection specimens available for review (n = 4). Tumors were diffusely positive for AGGRECAN and CD99 (7/7), and a subset expressed Pan-Keratin (AE1-AE3; 3/6), S100 (2/6), BCOR (2/6), ETV-4 (2/5), WT1 (2/6), and ERG (2/5). Desmin, NKX3-1, and SATB2 were negative (0/6). Diffuse AGGRECAN staining was also seen in 8/129 round cell sarcomas used for comparison, including mesenchymal chondrosarcoma (7/26) and CIC-sarcoma (1/26). Array-CGH showed complex karyotypes with recurrent deletions of tumor suppressor genes (CDKN2A/B, TUSC7, and DMD) in three FUS-NFATC2 cases and a simpler profile without homozygous losses in one EWSR1-NFATc2 case. Segmental chromosomal gains covering the loci of the fusion genes were detected in both variants. Overall, our study confirms and expands previous observations on NFATc2-sarcomas and supports that AGGRECAN is a useful biomarker of these tumors.

Molecular and clinicopathologic characterization of intravenous leiomyomatosis

Intravenous leiomyomatosis (IVL) is an unusual uterine smooth muscle proliferation that can be associated with aggressive clinical behavior despite a histologically benign appearance. It has some overlapping molecular characteristics with both uterine leiomyoma and leiomyosarcoma based on limited genetic data. In this study, we assessed the clinical and morphological characteristics of 28 IVL and their correlation with molecular features and protein expression, using array comparative genomic hybridization (aCGH) and Cyclin D1, p16, phosphorylated-Rb, SMARCB1, SOX10, CAIX, SDHB and FH immunohistochemistry. The most common morphologies were cellular (n = 15), usual (n = 11), and vascular (n = 5; including 3 cellular IVL showing both vascular and cellular features). Among the immunohistochemical findings, the most striking was that all IVL showed differential expression of either p16 or Cyclin D1 in comparison to surrounding nonneoplastic tissue. Cytoplasmic phosphorylated-Rb was present in all but one IVL with hyalinization. SMARCB1, FH, and SDHB were retained; S0X10 and CAIX were not expressed. The most common genetic alterations involved 1p (39%), 22q (36%), 2q (29%), 1q (25%), 13q (21%), and 14q (21%). Hierarchical clustering analysis of recurrent aberrations revealed three molecular groups: Groups 1 (29%) and 2 (18%) with associated del(22q), and Group 3 (18%) with del(10q). The remaining IVL had nonspecific or no alterations by aCGH. Genomic index scores were calculated for all cases and showed no significant difference between the 14 IVL associated with aggressive clinical behavior (extrauterine extension or recurrence) and those without (median scores 5.15 vs 3.5). Among the 5 IVL associated with recurrence, 4 had a vascular morphology and 3 had alterations of 8q. Recurrent chromosome alterations detected herein overlap with those observed in the spectrum of uterine smooth muscle tumors and involve genes implicated in mesenchymal tumors at different sites with distinct morphological features.

Smooth muscle tumors of the gastrointestinal tract: an analysis of prognostic features in 407 cases

Smooth muscle tumors represent the second most common mural mesenchymal neoplasm in the gastrointestinal tract, but established criteria for prognostic assessment of these tumors are lacking. A large cohort of surgically resected intramural gastrointestinal smooth muscle tumors from 31 institutions was analyzed to identify potential prognostic features. Pathologic features were assessed by expert gastrointestinal and/or soft tissue pathologists at each center. Immunohistochemical confirmation was required. A total of 407 cases from the esophagus (n = 97, 24%), stomach (n = 180, 44%), small bowel (n = 74, 18%), and colorectum (n = 56, 14%) were identified. Patients ranged in age from 19 to 92 years (mean 55 years), with a slight female predominance (57%). Mean tumor size was 5.4 cm, with the largest tumor measuring 29 cm. Disease progression following surgery, defined as local recurrence, metastasis, or disease-related death, occurred in 56 patients (14%). Colorectal tumors were most likely to progress, followed by small bowel and gastric tumors. None of the esophageal tumors in this series progressed. Receiver operator characteristic analysis identified optimal cutoffs of 9.8 cm and 3 mitoses/5 mm² for discriminating between progressive and non-progressive tumors. Histologic features strongly associated with progression by univariate analysis included moderate-to-severe atypia, high cellularity, abnormal differentiation (defined as differentiation not closely resembling that of normal smooth muscle), tumor necrosis, mucosal ulceration, lamina propria involvement, and serosal involvement (P < 0.0001 for all features). Age, sex, and margin status were not significantly associated with progression (P = 0.23, 0.82, and 0.07, respectively). A risk assessment table was created based on tumor site, size, and mitotic count, and Kaplan-Meier plots of progression-free survival for each subgroup revealed progression-based tiers. Based on our findings, it appears that nonesophageal gastrointestinal smooth muscle tumors measuring >10 cm and/or showing ≥3 mitoses/5 mm² may behave aggressively, and therefore close clinical follow-up is recommended in these cases.

Ultrasound and clinical characteristics of uterine smooth muscle tumors of uncertain malignant potential (STUMPs)

OBJECTIVE(S)

Smooth muscle tumors of uncertain malignant potential are rare uterine neoplasms. Their identification through imaging is still limited due to the few available descriptions in the scientific literature. The objective of this paper is to provide clinical and ultrasound features that could support an early identification of these neoplasms.

STUDY DESIGN

We retrospectively evaluated preoperative sonographic data of patients receiving a histopathological diagnosis of smooth muscle tumors of uncertain malignant potential between 2014 and 2019 at the S. Anna Hospital (Turin, Italy), a tertiary gynecological center. Tumors were characterized on the basis of ultrasound images using terms and definitions according to the morphological uterus sonographic assessment group.

RESULTS

A total of fourteen patients with smooth muscle tumors of uncertain malignant potential (20 lesions, including 18 pure and 2 with associated leiomyosarcoma) were identified. The median age was 47 years (range 28-77) and nine (64%) patients were of reproductive age. Six patients (43%) were asymptomatic, two (14%) presented with abdominal pain, two (14 %) with menorrhagia and four (29%) with both symptoms. Two (14%) patients developed local recurrences as uterine smooth muscle tumor of uncertain malignant potential and leiomyosarcoma, respectively. At ultrasound imaging, nine (69%) smooth muscle tumors of uncertain malignant potential were poorly or moderately vascularized and nine (82%) showed both circumferential and intra-lesional flows. Only three (15%) showed shadowing. The outlines were well-defined in seventeen cases (85%) and most (90%) showed isoechoic or mixed echogenicity with microcystic anechoic areas in fourteen (70%) of cases.

CONCLUSION(S)

Sonographic features of smooth muscle tumors of uncertain malignant potential may vary and a pathognomonic description has not been recognized. However, the identification of single or multiple lesions with specific ultrasound features should raise the suspicion of tumors of uncertain malignant potential. These features include isoechogenicity or mixed echogenicity, regular borders, presence of internal microcystic and anechoic areas, circumferential and intralesional vascularization ranging from minimal to high and absence of shadowing.

Reasons to Reconsider Risk Associated With Power Morcellation of Uterine Fibroids

Our insights into the molecular pathogenesis of uterine smooth muscle tumors have improved significantly. Accordingly, in the present review, we advocate a more refined risk assessment for patients considering surgical removal of fibroids or hysterectomy, respectively, requiring morcellation. For this procedure, the risk estimates given for the iatrogenic spread of a previously unexpected malignancy considerably vary among different studies. Nearly all previous studies conducted retrospectively refer to the risk of a patient having an unexpected malignancy at the time of surgery. We feel that, more appropriately, risk should refer to the number of tumors because, as a rule, every single nodule arises independently and, thus, carries an independent risk of being malignant or not. Furthermore, whether so-called parasitic fibroids carry an underestimated risk of stepwise malignant transformation is discussed.

Clinical experience of uterine smooth muscle tumor of uncertain malignant potential in two gynecological centers: Oncological and obstetrical aspects

OBJECTIVES

To evaluate the clinical characteristics and obstetrical and oncological outcomes of patients with uterine smooth muscle tumors of uncertain malignant potential (STUMP) and analyze the risk factors for recurrence.

STUDY DESIGN

A retrospective cohort study was performed at two gynecological centers using data collected between January 2008 and August 2018. All the patients enrolled were diagnosed with STUMP and had been followed up for at least 6 months. The patients' characteristics, treatment methods, recurrence rate, and subsequent pregnancy outcomes were evaluated.

RESULTS

The mean age of the 62 patients was 36.1 ± 9.1 years (median 35, range 20-55 years) and mean follow-up duration was 36.3 ± 26.8 months (29.5, 6-130). All the patients were of premenopausal status. Fourteen patients (22.6 %) were initially treated by hysterectomy and 48 (77.4 %) by myomectomy. During the study period, three patients (4.8 %) experienced recurrence. However, there was no statistical difference between myomectomy and hysterectomy in terms of the rate of recurrence of STUMP or sarcoma, and all patients survived even after recurrence. Multivariate analysis revealed that a history of previous myomectomy was the sole independent risk factor for recurrence (odds ratio = 51.071; 95 % confidence interval = 2.743-950.726; p = 0.008). Subsequent pregnancies were successful in 10 of 19 women (52.6 %) who tried to conceive. Two of them had ongoing pregnancies at the time of last follow-up; the remaining eight women experienced a total of 14 subsequent pregnancies.

CONCLUSIONS

The recurrence rate of STUMP was similar between hysterectomy and myomectomy. Therefore, fertility sparing myomectomy can be considered in women diagnosed with STUMP with close monitoring.

Myxoid smooth muscle neoplasia of the uterus: comprehensive analysis by next-generation sequencing and nucleic acid hybridization

Uterine myxoid smooth muscle tumors, including myxoid leiomyosarcoma, are rare and their genomic profile has not been fully characterized. With the discovery of uterine sarcomas with ZC3H7B-BCOR fusion and BCOR internal tandem duplications, the differential diagnosis of myxoid smooth muscle lesions is expanding to include molecularly-defined tumors. Thus, we aimed to explore the genomic landscape of myxoid smooth muscle tumor using comprehensive tools. We performed whole exome next-generation sequencing and a pan-sarcoma RNA fusion assay in tumoral paraffin-embedded tissue from nine well-characterized uterine myxoid smooth muscle tumors (seven myxoid leiomyosarcomas and two myxoid smooth muscle tumors of unknown malignant potential). By immunohistochemistry, all tumors were strongly positive for smooth muscle markers and negative for BCOR staining; 4/6 expressed PLAG1. None of the tumors harbored known fusions including ZC3H7B-BCOR, TRPS1-PLAG1, and RAD51B-PLAG1. None harbored exon 15 BCOR internal tandem duplications; however, four tumors contained BCOR internal tandem duplications of unknown significance (mostly intronic). Mutational burden was low (median 3.8 mutations/megabase). DNA damage repair pathway gene mutations, including TP53 and BRCA2, were found. Copy number variation load, inferred from sequencing data, was variable with genomic indexes ranging from 2.2 to 74.7 (median 25.7), with higher indexes in myxoid leiomyosarcomas than myxoid smooth muscle tumors of unknown malignant potential. The absence of clear driver mutations suggests myxoid smooth muscle tumors to be genetically heterogeneous group of tumours and that other genetic (eg., undiscovered translocation) or epigenetic events drive the pathogenesis of uterine myxoid smooth muscle neoplasia.

Secondary cytoreductive surgery in recurrent uterine leiomyosarcoma: a multi-institutional study

INTRODUCTION

Uterine leiomyosarcoma (uLMS) represents a rare gynecological malignancy with high incidence of recurrence. Evidence in literature about the management of recurrent uLMS is limited, and the role of secondary cytoreduction has been evaluated in small and heterogeneous populations. The objective of this study is to assess the prognostic role of secondary cytoreductive surgery and its related complications in a large and homogeneous group of patients.

METHODS

All consecutive patients who underwent surgery for recurrent uLMS between 01/2010-01/2018 at four Italian tertiary referral centers, were included. Relevant demographic and clinico-pathologic data were retrieved. Survival curves were estimated by Kaplan-Meier method and compared by log-rank test. Cox-proportional hazard model was used to assess the effect of the most predictive prognostic variables.

RESULTS

38 patients with recurrent uLMS were treated with secondary cytoreductive surgery in the study period. Recurrence presented as isolated disease in 17 (44.7%) cases. Bowel, bladder and upper abdominal surgery was performed in 50.0%, 18.4% and 28.9% of the cases, respectively. No residual tumor was the final surgical result in 35 (92.1%) patients. Median hospital stay was 7 days (range, 1-24). No women had major intra-operative and 4 (33.3%) had major post-operative complications. No patient died within 30-days from the secondary cytoreduction. Median time to the first cycle of adjuvant chemotherapy was 41-days (range, 29-78). Median recurrence-free survival was 16.0months (95%CI,11.6 to 26.1). 5-year overall survival (OS) was 76% (95%CI,53 to 89%). Time to first recurrence >12months significantly affected OS (p=0.04).

DISCUSSION

Secondary cytoreduction in recurrent uLMS often requires complex and extensive surgical procedures. Referral to tertiary centers guarantees low peri-operative morbidity, short length of hospitalization and median time to chemotherapy within the standard of care. Therefore, secondary cytoreduction to no residual disease is an option that may be considered in recurrent uLMS, especially in patients with time to first recurrence >12months.

[Mesenchymal and mixed uterine tumors : Current overview and practical aspects]

Benign leiomyomas are the most frequent mesenchymal tumors of the uterus. In contrast, uterine sarcomas are very rare. Leiomyosarcomas are the most frequent sarcomas followed by endometrial stromal sarcomas (ESS). Leiomyosarcomas are characterized by marked nuclear atypia and high mitotic count and may also show tumor cell necrosis and myometrial and vascular invasion. For cases of diagnostic uncertainty, the category of smooth muscle tumor of uncertain malignant potential (STUMP) may be considered but should be rarely used. Besides low-grade ESS and stromal nodules, a category of high-grade ESS was reconsidered by the WHO in 2014. High-grade ESS are characterized by fibromyxoid and round cell histology, myoinvasive growth, and immunoreactivity for cyclin D1 and BCOR and distinct gene fusions involving YWHAE and BCOR, respectively. The very rare undifferentiated uterine sarcomas need to be redefined due to overlap with high-grade ESS. Uterine tumors resembling ovarian sex cord tumors (UTROSCT) rarely behave malignant, but need to be distinguished from endometrial carcinomas. Mixed epithelial and mesenchymal tumors of the uterus are rare with carcinosarcomas occurring more frequently than adenosarcomas. For prognosis of adenosarcomas the recognition of sarcomatous overgrowth is crucial. Carcinosarcomas are histologically heterogeneous although genetically clonal; biologically they are considered as undifferentiated carcinomas. There will be an increasing importance of molecular pathology for the classification of rare and unusual mesenchymal uterine tumors.

Uterine smooth muscle tumors of unknown malignant potential: A challenging question

Uterine smooth muscle tumors of unknown malignant potential [STUMP]s are neoplasms with pathological features that preclude an equivocal diagnosis of leiomyosarcoma, but that do not fulfill the criteria for leiomyoma or its variants, and raise concerns that the tumors may behave in a malign fashion. Total hysterectomy with or without bilateral salpingo-oophorectomy is the standard treatment if fertility is completed, whereas myomectomy alone can be taken into consideration in young patients who desire to preserve childbearing potential. A careful surveillance every 6 months for 5 years and then yearly is strongly warranted. Patients with STUMP can relapse as either STUMP or leiomyosarcoma in approximately 11-13% of the cases, and their 5-year overall survival ranges from 92 to 100%. The present paper reviews the clinicopathological features of uterine STUMPs with a particular focus on most commonly accepted histopathological criteria for the diagnosis and on biological behaviour of these controversial neoplasms.

The Usefulness of Immunohistochemistry in the Differential Diagnosis of Lesions Originating from the Myometrium

Uterine leiomyomas (LMs), currently the most common gynecological complaint around the world, are a serious medical, social and economic problem. Accurate diagnosis is the necessary prerequisite of the diagnostic-therapeutic process. Statistically, mistakes may occur more often in case of disease entities with high prevalence rates. Histopathology, based on increasingly advanced immunohistochemistry methods, is routinely used in the diagnosis of neoplastic diseases. Markers of the highest sensitivity and specificity profiles are used in the process. As far as LMs are concerned, the crux of the matter is to identify patients with seemingly benign lesions which turn out to be suspicious (e.g., atypical LM) or malignant (e.g., leiomyosarcoma (LMS)), which is not uncommon. In this study, we present the current state of knowledge about the use of immunohistochemical markers in the differential diagnosis of LM, atypical LM, smooth muscle tumors of uncertain malignant potential (STUMP), and LMS, as well as their clinical predictive value.

Uterine smooth muscle tumor of uncertain malignant potential: fertility and clinical outcomes

Objective

In this study, we aimed to evaluate the clinicopathological features, obstetric, and oncological outcomes of patients diagnosed with a uterine smooth muscle tumors of uncertain malignant potential (STUMP).

Methods

A dual-institutional, database review was carried out to screen patients with STUMP who were treated with upfront surgery between January 2006 and December 2017. Data including age at the time of diagnosis, recurrence rate, disease-free survival, overall survival, and fertility outcomes were retrospectively analyzed.

Results

Fifty-seven patients with STUMPs were included in the study. The median age at the time of diagnosis was 42 (range, 16 to 75) years. The median follow-up was 57 (range, 16 to 125) months. Eight patients (14%) had recurrence during follow-up. Recurrent STUMPs were seen in seven patients and leiomyosarcoma after 14 months in one patient. Seven patients with a recurrent STUMP survived, while the remaining patient died. Recurrence rates were similar for women who underwent myomectomy and those who underwent hysterectomy. The presence of uterine localization of tumor (subserosal vs intramural-submucosal) statistically significantly affected recurrence rates (odds ratio=5.72; 95% confidence interval=1.349–24.290; p=0.018). Ten of 27 patients who underwent myomectomy for uterine myoma had fertility desire. Seven pregnancies were recorded.

Conclusions

Our study results suggest that fertility-sparing approaches are feasible in patients with STUMP, although recurrence may be seen.

Integrated Molecular Analysis of Undifferentiated Uterine Sarcomas Reveals Clinically Relevant Molecular Subtypes

PURPOSE

Undifferentiated uterine sarcomas (UUS) are rare, extremely deadly, sarcomas with no effective treatment. The goal of this study was to identify novel intrinsic molecular UUS subtypes using integrated clinical, histopathologic, and molecular evaluation of a large, fully annotated, patient cohort.

EXPERIMENTAL DESIGN

Fifty cases of UUS with full clinicopathologic annotation were analyzed for gene expression (n = 50), copy-number variation (CNV, n = 40), cell morphometry (n = 39), and protein expression (n = 22). Gene ontology and network enrichment analysis were used to relate over- and underexpressed genes to pathways and further to clinicopathologic and phenotypic findings.

RESULTS

Gene expression identified four distinct groups of tumors, which varied in their clinicopathologic parameters. Gene ontology analysis revealed differential activation of pathways related to genital tract development, extracellular matrix (ECM), muscle function, and proliferation. A multivariable, adjusted Cox proportional hazard model demonstrated that RNA group, mitotic index, and hormone receptor expression influence patient overall survival (OS). CNV arrays revealed characteristic chromosomal changes for each group. Morphometry demonstrated that the ECM group, the most aggressive, exhibited a decreased cell density and increased nuclear area. A cell density cutoff of 4,300 tumor cells per mm² could separate ECM tumors from the remaining cases with a sensitivity of 83% and a specificity of 94%. IHC staining of MMP-14, Collagens 1 and 6, and Fibronectin proteins revealed differential expression of these ECM-related proteins, identifying potential new biomarkers for this aggressive sarcoma subgroup.

CONCLUSIONS

Molecular evaluation of UUS provides novel insights into the biology, prognosis, phenotype, and possible treatment of these tumors.