Myxoid Pseudotumor Changes Affecting the Distal Ureter Associated With Urothelial Carcinoma In Situ

Myxoid pseudotumor is a pseudoneoplastic fibroblastic proliferation that has been described in the perinephric and renal sinus fat tissue. It is characterized by the presence of a myxoid matrix, intermingled with the adipocytes, and a hypocellular population of spindle-shaped and stellate cells. We report a myxoid pseudotumor involving the distal ureter, which broadens the spectrum of possible localizations of this lesion around the urinary tract. It occurred in an 80-year-old patient who underwent a nephroureterectomy indicated after an incidental radiological finding of a thickening of the distal left ureter wall which suggested a ureteral neoplasm. He had two voided urine and one ureteroscopic sample cytologies diagnosed as high-grade urothelial carcinoma, as well as a retrograde ureteroscopy ureteral biopsy which was diagnosed as urothelial carcinoma in situ. This emphasizes the problem of the possible misdiagnosis of myxoid pseudotumor as a ureteral infiltrative carcinoma due to the radiological findings being badly interpreted, compounded by the preoperative cytohistologic data on malignancy. A diffuse urothelial carcinoma in situ was seen in our specimen without infiltrative or papillary tumors. This would not support an obstructive pathogenetic mechanism as has been hypothesized for myxoid pseudotumor.

Novel CRTC1::MRTFB(MKL2) Gene Fusion detected in Myxoid Mesenchymal Neoplasms with Myogenic Differentiation involving Bone and Soft Tissue

Appropriate classification of fusion-driven bone and soft tissue neoplasms continues to evolve, often relying on the careful integration of morphologic findings with immunohistochemical, molecular, and clinical data. Herein, we present three cases of a morphologically distinct myxoid mesenchymal neoplasm with myogenic differentiation and novel CRTC1::MRTFB (formerly MKL2) gene fusion. Three tumors occurred in 2 female and 1 male patient with a median age of 72 (range: 28-78). Tumors involved the left iliac bone, the right thigh, and the left perianal region with a median size of 4.0 cm (4.0-7.6 cm). While one tumor presented as an incidental finding, the other two tumors were noted given their persistent growth. At the time of last follow-up, one patient was alive with unresected disease at 6 months, one patient was alive without evidence of disease at 12 months after surgery and one patient died of disease 24 months after diagnosis. On histologic sections, the tumors showed multinodular growth and were composed of variably cellular spindle to round-shaped cells with distinct brightly eosinophilic cytoplasm embedded within a myxoid stroma. One tumor showed overt smooth muscle differentiation. Cytologic atypia and mitotic activity ranged from minimal (2 cases) to high (1 case). By immunohistochemistry, the neoplastic cells expressed focal smooth muscle actin, h-caldesmon, and desmin in all tested cases. Skeletal muscle markers were negative. Next-generation sequencing detected nearly identical CRTC1::MRTFB gene fusions in all cases. We suggest that myxoid mesenchymal tumors with myogenic differentiation harboring a CRTC1::MRTFB fusion may represent a previously unrecognized, distinctive entity that involves soft tissue and bone. Continued identification of these novel myxoid neoplasms with myogenic differentiation will be important in determining appropriate classification, understanding biologic potential, and creating treatment paradigms.

Expanding the Spectrum of NR4A3 Fusion-Positive Gynecologic Leiomyosarcomas

Recurrent gene fusions have been observed in epithelioid and myxoid variants of uterine leiomyosarcoma. PGR::NR4A3 fusions were recently described in a subset of epithelioid leiomyosarcomas exhibiting rhabdoid morphology. In this study, we sought to expand the clinical, morphologic, immunohistochemical, and genetic features of gynecologic leiomyosarcomas harboring NR4A3 rearrangements with PGR and novel fusion partners. We identified 9 gynecologic leiomyosarcomas harboring PGR::NR4A3, CARMN::NR4A3, ACTB::NR4A3, and possible SLCO5A1::NR4A3 fusions by targeted RNA sequencing. Tumors frequently affected premenopausal women, involving the uterine corpus, uterine cervix, or pelvis. All were similarly characterized by lobules of monomorphic epithelioid and/or spindled cells arranged in sheets, cords, trabeculae, and micro- and macrocysts associated with abundant myxoid matrix and hemorrhage, creating labyrinth-like or pulmonary edema-like architecture. Myogenic differentiation with frequent estrogen receptor and progesterone receptor staining and no CD10 expression characterized all tumors. All cases showed high NR4A3 RNA expression levels and NOR1 (NR4A3) nuclear staining similar to salivary gland acinic cell carcinomas and a subset of extraskeletal myxoid chondrosarcomas harboring NR4A3 rearrangements. NOR1 (NR4A3) immunohistochemistry may serve as a useful diagnostic marker of NR4A3 fusion-positive gynecologic leiomyosarcomas.

Metastatic cutaneous myxosarcoma in an adult horse

A 25-year-old mixed-breed equine with separate nodular cutaneous lesions in the right thoracic limb (RTL) and right ventral abdominal region was admitted to a Veterinary Hospital in Belo Horizonte, Minas Gerais. Fine-needle aspiration cytology was performed on the RTL lesion and superficial cervical lymph node, and the results were suggestive of a malignant neoplasm known as myxosarcoma. Due to the unfavorable prognosis, the animal was euthanized. Based on the macroscopic and microscopic findings, the diagnosis of metastatic cutaneous myxosarcoma was confirmed. Although rare, this tumor should be considered as a differential diagnosis for cutaneous neoplasms in this species.

Myxoid epithelioid smooth muscle tumor of the vulva: A distinct entity with MEF2D::NCOA2 gene fusion

Smooth muscle tumors are the most common mesenchymal tumors of the female genital tract, including the vulva. Since vulvar smooth muscle tumors are rare, our understanding of them compared to their uterine counterparts continues to evolve. Herein, we present two cases of morphologically distinct myxoid epithelioid smooth muscle tumors of the vulva with novel MEF2D::NCOA2 gene fusion. The tumors involved 24 and 37-year-old women. Both tumors presented as palpable vulvar masses that were circumscribed, measuring 2.8 and 5.1 cm in greatest dimension. Histologically, they were composed of epithelioid to spindle-shaped cells with minimal cytologic atypia and prominent myxoid matrix. Rare mitotic figures were present (1-3 mitotic figures per 10 high-power field (HPF)), and no areas of tumor necrosis were identified. By immunohistochemistry, the neoplastic cells strongly expressed smooth muscle actin, calponin, and desmin, confirming smooth muscle origin. Next-generation sequencing identified identical MEF2D::NCOA2 gene fusions. These two cases demonstrate that at least a subset of myxoid epithelioid smooth muscle tumors of the vulva represent a distinct entity characterized by a novel MEF2D::NCOA2 gene fusion. Importantly, recognition of the distinct morphologic and genetic features of these tumors is key to understanding the biological potential of these rare tumors.

Retroperitoneal liposarcoma: unveiling diagnostic delays and multimodal treatment dilemmas

Liposarcomas are a prevalent subtype of soft tissue sarcomas, constituting less than 1% of all malignancies. Originating in the adipose tissue, they can manifest in various locations and are categorized by the World Health Organization into several subtypes: well-differentiated liposarcomas, dedifferentiated liposarcomas, myxoid liposarcomas, pleomorphic liposarcomas and mixed-type liposarcomas. These tumors typically affect middle-aged and older individuals, and their incidence has been progressively increasing over the years. As liposarcomas advance they tend to encase blood vessels and major organs, particularly in the retroperitoneal area. Often asymptomatic initially, symptoms arise as the tumor reaches a considerable size, exerting pressure on adjacent tissues and organs. This report features a 54-year-old patient incidentally diagnosed with a substantial retroperitoneal tumor extending to the antero-lateral abdominal wall and inner thigh via the right inguinal ligament. The patient, with a previous three-year history of a right inguinal mass, sought acute care for a perianal abscess The histological examination revealed morphological aspects consistent with a low-grade myxoid liposarcoma. While surgery remains the primary treatment for retroperitoneal liposarcomas, controversies exist regarding the role of radiotherapy and chemotherapy in improving survival rates. This case highlights the challenges in managing retroperitoneal tumors and underscores the importance of a personalized, multidisciplinary approach to optimize patient outcomes.

Pseudocystic myxoid liposarcoma of the posterior chest wall - a rare case report

Introduction and importance

Liposarcoma (LPS) is a common soft-tissue sarcoma predominantly diagnosed in adults, arising from malignant adipose cells. Among its various subtypes, myxoid LPS (MLPS) stands out as the second most frequent, accounting for ~30% of all LPS cases. This particular subtype typically manifests in males between the ages of 40 and 50 and is commonly found in the lower extremities. Although rare, MLPS may also occur in the head, neck, and infrequently in the back. Chest wall LPS cases are also sparsely reported.

Case presentation

In this report, we present a case of MLPS in a 69-year-old male patient who presented with a complaint of firm swelling on the right posterior chest wall, which was progressively increasing in size over the past 10 years. The tumour was located in the posterior chest wall on the left side, and further diagnostic evaluation using computed tomography (CT) and MRI was conducted to identify its characteristics and extent.

Clinical discussion

The use of CT scanning plays a crucial role in differentiating between various lipomatous tumour types, aiding in the identification and classification of MLPS. However, MRI emerges as a more effective technique for detecting microscopic fat compared to CT or ultrasonography, providing valuable insights for accurate diagnosis and treatment planning.

Conclusion

Surgery remains the primary therapeutic approach for managing LPSs, including MLPS. Adjuvant preoperative radiation is recommended due to its significant sensitivity and potential for improved outcomes. Given the rarity of this presentation and the varied anatomical locations, a multidisciplinary approach is paramount in effectively managing such cases. Medical practitioners should collaborate closely, considering the unique challenges posed by MLPS to ensure optimal patient care and treatment outcomes.

A rare encounter: Comprehensive case review of myxoid meningiomas with a representative case

Meningiomas are the most diagnosed primary central nervous system tumor. Currently, 15 different subtypes of meningioma exist with various characteristics. One extremely rare subtype is myxoid meningioma, which is a World Health Organization grade 1 benign meningioma. These specific meningiomas have only been reported 12 times in the literature. In this representative case, we present a 46-year-old female patient with a left frontal myxoid meningioma, describe the findings on imaging, and provide the histopathological features that are needed for diagnosis. Furthermore, this report discusses the other existing myxoid meningioma case reports found throughout the literature.

PDE3A Is a Highly Expressed Therapy Target in Myxoid Liposarcoma

Liposarcomas (LPSs) are a heterogeneous group of malignancies that arise from adipose tissue. Although LPSs are among the most common soft-tissue sarcoma subtypes, precision medicine treatments are not currently available. To discover LPS-subtype-specific therapy targets, we investigated RNA sequenced transcriptomes of 131 clinical LPS tissue samples and compared the data with a transcriptome database that contained 20,218 samples from 95 healthy tissues and 106 cancerous tissue types. The identified genes were referred to the NCATS BioPlanet library with Enrichr to analyze upregulated signaling pathways. PDE3A protein expression was investigated with immunohistochemistry in 181 LPS samples, and PDE3A and SLFN12 mRNA expression with RT-qPCR were investigated in 63 LPS samples. Immunoblotting and cell viability assays were used to study LPS cell lines and their sensitivity to PDE3A modulators. We identified 97, 247, and 37 subtype-specific, highly expressed genes in dedifferentiated, myxoid, and pleomorphic LPS subtypes, respectively. Signaling pathway analysis revealed a highly activated hedgehog signaling pathway in dedifferentiated LPS, phospholipase c mediated cascade and insulin signaling in myxoid LPS, and pathways associated with cell proliferation in pleomorphic LPS. We discovered a strong association between high PDE3A expression and myxoid LPS, particularly in high-grade tumors. Moreover, myxoid LPS samples showed elevated expression levels of SLFN12 mRNA. In addition, PDE3A- and SLFN12-coexpressing LPS cell lines SA4 and GOT3 were sensitive to PDE3A modulators. Our results indicate that PDE3A modulators are promising drugs to treat myxoid LPS. Further studies are required to develop these drugs for clinical use.

A Rare Case of Uterine Myxoid Leiomyosarcoma

A 49-year-old female patient was referred to a tertiary care hospital with a history of postmenopausal bleeding and abdominal pain that had persisted for the last two months. An abdominal examination revealed a huge mass that had been present for 12 weeks. A fibroid uterus was suggested by USG. A biopsy was done and sent to histopathology which revealed myxoid leiomyoma. Subsequently, the patient underwent total abdominal hysterectomy without bilateral salpingo-oophorectomy. Histopathological examination confirmed the diagnosis of myxoid leiomyosarcoma (MLMS) of the uterus.

Metastatic Adrenocortical Carcinoma With Chromothripsis: A Case Report and Literature Review

Metastatic adrenocortical carcinoma (ACC) often has a poor outcome, with a five-year survival of less than 25%. We report a rare case of metastatic ACC with a myxoid variant with chromothripsis. We review the histologic variants of ACC, including myxoid type, molecular drivers, and current and investigational therapies for adrenocortical carcinoma. We also discuss the mechanism of chromothripsis, chromothripsis in ACC tumorigenesis, and propose potential therapies targeting chromothripsis.

The Conundrum of Dedifferentiation in a Liposarcoma at a Peculiar Location: A Case Report and Literature Review

Dedifferentiated liposarcoma of the deep soft tissue of the lower extremities is an infrequent finding. Myxoid liposarcoma is considered the most common soft tissue neoplasia arising in this anatomic region. Divergent differentiation usually occurs within well-differentiated liposarcoma and is exceedingly rare in a myxoid liposarcoma. We report a 32-year-old man who developed a dedifferentiated liposarcoma of the thigh on the background of a pre-existing myxoid liposarcoma. The gross examination of the surgical specimen showed a 11/7/2 cm tumour mass with solid tan-grey areas and focal myxoid degeneration. The microscopic examination revealed a malignant lipogenic proliferation, containing round cells with hyperchromatic nuclei and atypical lipoblasts, confined to the basophilic stroma with a myxoid aspect. Abrupt transition towards a hypercellular, non-lipogenic area consisting of highly pleomorphic spindle cells with atypical mitotic figures was also noted. Immunohistochemical staining was performed. Tumour cells in the lipogenic area were intensely positive for S100 and p16, and CD34 staining highlighted an arborizing capillary network. The dedifferentiated tumour areas showed positive MDM2 and CDK4 staining within neoplastic cells, with the Ki 67 proliferation marker expressed in approximately 10% of the cells. Wild-type TP53 protein expression pattern was documented. Thus, the diagnosis of a dedifferentiated liposarcoma was established. This paper aims to provide further knowledge about liposarcomas with divergent differentiation at peculiar locations, emphasizing the importance of histopathologic examination and immunohistochemical analysis for establishing the diagnosis and assessing the therapeutic response and prognosis of this condition.

A Rare Case of Myxoid Adrenocortical Carcinoma

Myxoid adrenocortical carcinoma (myxoid ACC) is a rare subtype of adrenal cortical carcinoma with only a few cases reported in the literature. This tumor is characterized by small to large neoplastic cells in cords, diffuse sheets, or nodular architecture, which are surrounded by variable amounts of myxoid material. We are presented with an elderly female with a suprarenal mass which revealed a tumor composed of neoplastic cells surrounded by scant to abundant myxoid stroma. Expression for Melan-A, Inhibin, Synaptophysin, and Pancytokeratin, as well as a Ki-67 proliferative index of 15%, warrant a diagnosis of myxoid ACC.

Myxoid pleomorphic liposarcoma in the teres minor muscle: A case report

RATIONALE

Myxoid pleomorphic liposarcoma (MPL) is a rare aggressive adipocytic tumor that mainly presents in children and adolescents. It is most frequently observed in the mediastinum and rarely in the head and neck, perineal region, or back. Herein, we report the first published case of MPL of the teres minor muscle.

PATIENT CONCERNS

A 24-years-old woman presented with a painless palpable mass in her right shoulder.

DIAGNOSES

Magnetic resonance imaging identified a 9.0 × 7.0 × 4.0 cm mass suspected to be a sarcoma in the teres minor muscle. Positron emission tomography/computed tomography revealed no evidence of distant metastasis. Histopathological examination revealed the mass to be an MPL, which was assigned a histologic grade of 3 according to the French Federation of Cancer Centers Sarcoma Group system. No tumor cells were observed along the resected margins.

INTERVENTIONS

Under general anesthesia, the right teres minor muscle containing the mass was excised en bloc and frozen biopsy confirmed that the tumor cells did not invade the surrounding tissues.

OUTCOMES

The patient underwent radiotherapy and was followed up for 6 months without complications.

LESSONS

Although MPL in the teres minor muscle is rare, it should be considered in the differential diagnosis in patients with a mass in the teres minor muscle due to its poor prognosis.

Superficial CD34 Positive Fibroblastic Tumour with Myxoid Stroma

Superficial CD34 positive fibroblastic tumor is a rare low-grade neoplasm of the skin and subcutis with indolent behavior. This entity has been included in the current World Health Organisation (WHO) classification of soft tissue tumors. Pathological diagnosis can be challenging due to significant morphological overlap with other entities and the large spectrum of CD34 positive tumors. We report a case in a twenty-five male which showed characteristic diagnostic features, but in addition showed myxoid stroma. The presence of myxoid stroma has not been previously emphasized in this entity and broadens the histologic differential diagnosis significantly to include myxoid soft tissue tumors. A subset of these tumors harbor PRDM10-rearrangements, but a defining molecular feature has not yet been described, highlighting the need for further molecular characterization of this potentially genetically heterogenous tumor. Awareness of this entity among surgeons and pathologists is important to prevent misclassification as an aggressive sarcoma and avoid over-treatment.

An integrative histopathological and epigenetic characterization of primary intracranial mesenchymal tumors, FET:CREB-fused broadening the spectrum of tumor entities in comparison with their soft tissue counterparts

FET:CREB fusions have been described in a variety of tumors from various phenotypes. Recently, these fusion transcripts were reported in intracranial tumors, variably named intracranial mesenchymal myxoid tumors or angiomatoid fibrous histiocytomas. Controversy remains concerning the terminology for these tumors. Here, we report 11 cases of central nervous system mesenchymal tumors with proven FET:CREB fusion. Most DNA methylation profiles were not classifiable using the Heidelberg Brain Tumor or Sarcoma Classifier (v11b4/v12.2). However, by using unsupervised t‐SNE and hierarchical clustering analyses, six of the cases constituted a distinct cluster. The remaining four tumors showed no obvious relation to any of the other referenced classes but were close to the clusters of extra‐CNS angiomatoid fibrous histiocytomas (n = 1), clear cell sarcomas (n = 1), or solitary fibrous tumors (n = 2). Our findings confirm that intracranial FET:CREB‐fused tumors do not represent a single molecular tumor entity, although most samples clustered close to each other, indicating the existence of a distinct epigenetic group that could potentially be partially masked by the low number of cases included. Further analyses are needed to characterize intracranial FET:CREB fused‐defined tumors in more detail.

Vulvar Cutaneous Myxoma in a Patient With Carney Complex: Avoiding Pitfalls of Myxoid Lesions of the Vulva

We present the case of a 31-year-old woman who underwent surgical excision for a polypoid, vulvar lesion. Histopathological analysis showed a diffuse myxoid stroma admixed with scant collagen fibrils. Thin-walled and branching blood vessels were prominent, with a mild perivascular lymphocytic infiltrate. Cytologically bland spindle cells with inconspicuous nucleoli were immersed in a loose myxoid stroma. This combination of histopathological features along with multinodularity in the subcutaneous fat raised concern for deep angiomyxoma, a locally destructive neoplasm. Among our differential of myxoid lesions of the vulva, we ultimately favored the diagnosis of vulvar cutaneous myxoma. Upon further investigation, we learned that our patient was indeed known for the Carney complex. We highlight that vulvar cutaneous myxomas arising in the context of the Carney complex pose a significant diagnostic challenge for pathologists and should not be overdiagnosed as aggressive lesions such as deep angiomyxoma or other malignant stromal neoplasms.

[Adrenocortical cancer: morphological variants, immunohistochemical characteristics]

Adrenocortical cancer (ACC) is a rare endocrine malignancy of the adrenal cortex, which has an unfavorable prognosis and extremely aggressive clinical behavior in most cases. Nevertheless, cases of a more favorable disease course with late metastasis and slow progression have been described. In 2017, the International Agency for Research on Cancer (IARC) and the World Health Organization (WHO) in the 4^th edition of the Classification of Tumors of the Endocrine Organs identified histological variants of ACC, such as classical, oncocytic, myxoid, and sarcomatoid ones, indicating the morphological heterogeneity of this tumor.

OBJECTIVE

To provide a detailed description of the morphological variants of ACC with an emphasis on their histological characteristics and the expression of immunohistochemical markers.

MATERIALS AND METHODS

A total of 75 cases of ACC were analyzed in the adult population diagnosed as having the morphological variants in accordance with the International Histological Classification of Adrenal Tumors (WHO, 2017). Monoclonal antibodies to SF1, Inhibin A, Melan A, Ki-67, p53, and antimitochondrial antibodies were used for immunohistochemical diagnosis.

RESULTS

The classic, oncocytic, and myxoid subtypes of ACC were found in 51 (68%), 15 (20%), and 9 (12%) cases, respectively. The functional activity of the tumors was observed in 43% (n=18) in the classic variant of ACC; moreover, the clinical picture was manifested by the symptoms of hypercorticism (38%) and virilization (5%). There were no significant differences in hormonal activity between different morphological variants. The characteristics of the above histological variants of the tumor was determined with a description of growth patterns that can improve the diagnosis of ACC. The diagnosis of ACC can be confirmed by an immunohistochemical study; the required minimum panel of markers should include SF1, Melan A, and Inhibin A. The Ki-67 proliferative activity index showed significant differences (p=0.0056) when it was determined in the morphological variants of ACC.

CONCLUSION

Despite the determination of a minimal immunohistochemical panel to confirm the diagnosis of ACC, it is important to remember that each histological variant may be characterized by the different expression of immunohistochemical markers. The identification of morphological variants of ACC and the use of specific, sensitive, and prognostically significant immunohistochemical markers will allow clinicians and pathologists to more accurately judge the biological properties of this tumor and the clinical course of the disease.

Adrenocortical Carcinoma: Updates of Clinical and Pathological Features after Renewed World Health Organisation Classification and Pathology Staging

Adrenocortical carcinoma (ACC) is a heterogenous group of diseases with different clinical behaviour between adult and paediatric patients. In addition, three histological variants, oncocytic, myxoid and sarcomatoid are noted on the recent World Health Organisation (WHO) classification of ACC. A review of recent literature showed that the different types of ACC have distinctive demographic data, clinical presentation, pathology, biological behaviour, genomic and patients' prognosis. In addition, recent updates of pathology staging for ACC allow refinement of prognostic grouping for planning treatment of the patients with ACC. These advances in genomic, pathology and staging have driven the development of standardisation of pathology reporting. International standardisation of pathological reporting of adrenocortical carcinoma and adaption to local pathology communities provide universal platforms for clinicians and researchers involved in the management of patients with ACC. To conclude, all these advances in the field of pathology will improve development of management strategies including improvement of clinical care, development of prognostic markers and testing of novel therapeutic approaches for patients with adrenocortical carcinoma.

Uterine plexiform tumourlets: multifocal and solitary cases with subsets expressing melanocytic markers

AIMS

Uterine plexiform tumourlets are traditionally regarded as microscopic epithelioid leiomyomas. They are typically solitary incidental findings, but may be multifocal (plexiform leiomyomatosis). We aim to report novel immunohistochemical and morphological findings, specifically the presence of spindled and epithelioid cell nodules, in these lesions.

METHODS AND RESULTS

Three cases of plexiform leiomyomatosis and 16 solitary plexiform tumourlets were included. Two cases of plexiform leiomyomatosis and four solitary plexiform tumourlets demonstrated spindled and epithelioid cell nodules which, in one of the former cases, formed expansile masses up to 15 mm. The nodules demonstrated mild cytological atypia and occasional mitotic activity, and they were associated with a myxoid stroma and a lymphohistiocytic infiltrate which imparted a granulomatous appearance to the microscopic lesions. The plexiform tumourlets (solitary and multifocal) consistently expressed desmin, smooth muscle actin, ER and PR, and they commonly co-expressed melanocytic and perivascular epithelioid cell (PEC) markers HMB45, MiTF and cathepsin K. The spindled and epithelioid cell nodules were generally negative for myoid markers and hormone receptors, but expressed p16, cyclin D1 and TFE3. All lesions tested were negative for cytokeratin, S100, melanA, inhibin, EMA, ALK and BCOR; fluorescence in-situ hybridisation was negative for ALK, TFE3 and BCOR rearrangements in one of the larger spindled and epithelioid cell nodules.

CONCLUSIONS

Plexiform tumourlets commonly co-express myoid and melanocytic markers and may represent part of the spectrum of gynaecological PEC-related lesions. Some cases are associated with spindled and epithelioid cell nodules that could potentially mimic other uterine myxoid neoplasms.

Clinical outcomes of patients with advanced synovial sarcoma or myxoid/round cell liposarcoma treated at major cancer centers in the United States

BACKGROUND

Outcomes data regarding advanced synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are limited, consisting primarily of retrospective series and post hoc analyses of clinical trials.

METHODS

In this multi-center retrospective study, data were abstracted from the medical records of 350 patients from nine sarcoma centers throughout the United States and combined into a registry. Patients with advanced/unresectable or metastatic SS (n = 249) or MRCL (n = 101) who received first-line systemic anticancer therapy and had records of tumor imaging were included. Overall survival (OS), time to next treatment, time to distant metastasis, and progression-free survival (PFS) were evaluated using the Kaplan-Meier method and Cox regression.

RESULTS

At start of first-line systemic anticancer therapy, 92.4% of patients with SS and 91.1% of patients with MRCL had metastatic lesions. However, 74.7% of patients with SS and 72.3% of patients with MRCL had ≥2 lines of systemic therapy. Median OS and median PFS from first-line therapy for SS was 24.7 months (95% CI, 20.9-29.4) and 7.5 months, respectively (95% CI, 6.4-8.4). Median OS and median PFS from start of first-line therapy for MRCL was 29.9 months (95% CI, 27-44.6) and 8.9 months (95% CI 4.5-12.0).

CONCLUSIONS

To the best of our knowledge, this is the largest retrospective study of patients with SS and MRCL. It provides an analysis of real-world clinical outcomes among patients treated at major sarcoma cancer centers and could inform treatment decisions and design of clinical trials. In general, the survival outcomes for this selected population appear more favorable than in published literature.

Rare variants of solitary fibrous tumor

OBJECTIVE

Some cases of solitary fibrous tumor (SFT) exhibit unusual histologic features that may cause diagnostic difficulty, such as fascicular monotonous spindle cells accompanied by hyalinized blood vessels and numerous evenly distributed mast cells, and features mimicking myxoid liposarcoma. Awareness of these features is important for reaching correct diagnosis of similar cases.

METHODS

Three cases of SFT with the above unusual features were retrieved from our consult files for review, including H&E slides and immunohistochemical stains. In addition, FISH analysis for SS18-SSX (SYT), DDIT3 and MDM2 were performed. Furthermore, formalin-fixed paraffin-embedded (FFPE) tissue sections were tested for 8 fusion variants of NAB2-STAT6 by qualitative endpoint reverse-transcriptase (RT)-PCR.

RESULTS

Neoplastic cells from all 3 cases are positive for CD34, CD99, and STAT6 immunohistochemically. In addition, the tumors are positive for NAB2-STAT6 fusion gene. Mast cells from the first case possess nonneoplastic phenotype and are positive for CD117 and tryptase staining but negative for CD25.

CONCLUSIONS

The three cases studied here represent rare types of SFT, which differ from classical "pattern-less" pattern of SFT. Correct diagnosis required a combination of CD34 and STAT6 immunostaining and NAB2-STAT6 fusion gene analysis.

Ossifying fibromyxoid tumor: Fine-needle aspiration cytology findings of a rare soft tissue neoplasm

Ossifying fibromyxoid tumors (OFMTs) are rare tumors of uncertain origin and intermediate (rarely metastasizing) biologic potential, with characteristic morphology of an encapsulated tumor containing polygonal cells in an abundant fibromyxoid matrix surrounded by a peripheral layer of metaplastic lamellar bone. FNA cytology of OFMT has not been sufficiently reported and till date cytological features of only seven cases have been reported so far. We report another case of OFMT in a 55-year-old female presenting with longstanding swelling in thigh. On fine-needle aspiration, a tumor with moderate cellularity and myxoid areas was seen; coupled with compatible radiological findings, a diagnosis of OFMT was suggested. Establishing a correct diagnosis is important as although OFMT is benign in nature, local recurrences or rarely distant metastasis have been seen of this tumor. Hence, a high degree of suspicion with radiological correlation is of utmost importance for identification of this entity.

A Low-Grade Myxoid Liposarcoma Arising in a Deep-Seated Conventional Lipoma

Myxoid liposarcomas (MLS) are known to arise de novo and have not been shown to derive from previous benign lesions (lipomas), whereas lipomas occasionally harbor areas of other benign mesenchymal tissue. Rarely, tumors presenting with MLS or round cell liposarcomas together with conventional liposarcoma have been classified as mixed liposarcomas. However, no case of MLS arising in a conventional lipoma has been described. In this article, we report a case of a young male presenting with a deep-seated soft tissue tumor of the posterior part of the thigh. The tumor was removed en bloc. Grossing revealed a small encapsulated myxoid lesion (2.5 cm) within the larger lipomatous tumor (14 cm). Histological examination and cytogenetic analysis revealed a FUS-CHOP positive low-grade MLS arising in a conventional lipoma without histological atypia, FUS-CHOP fusion, or CDK4/MDM2 amplification. While we cannot conclude whether these were collision tumors or an MLS progression from a lipoma, this case highlights the value of careful grossing in the soft tissue setting.

Myxoid endometrial stromal sarcoma: report of two cases with emphasis on its diagnostic problems

AIMS

To address the diagnostic problems of uterine myxoid endometrial stromal tumor.

METHODS

We investigated the clinicopathologic and immunohistochemical features of 2 myxoid endometrial stromal sarcomas.

RESULTS

Patient 1 had a recurrent pelvic tumor. She had a history of abdominal hysterectomy for "uterine multiple leiomyomas" 3 years ago. The pelvic tumor and her previous uterine tumor were both composed of myofibroblast-like spindle cells, and small oval cells in a myxoid matrix. The mitotic figures were up to 3-4/10 HPFs. There were numerous small thin-walled vessels and anastomosing capillaries. Patient 2 had a gelatinous polypoid mass in the uterine cavity. The tumor harbored plump spindle tumor cells loosely embedded in the prominent myxoid matrix. It morphologically mimicked an inflammatory myofibroblastic tumor. However, it had a tongue-like myometrial invasion and vascular involvement. By immunohistochemistry, the tumor cells in both cases were all positive for CD10, and negative for caldesmon, CD117, CD34 and ALK.

CONCLUSIONS

Endometrial stromal tumors can show a substantial myxoid component. Careful morphologic assessment and immunohistochemical study will contribute to their distinction from myxoid leiomyosarcoma, inflammatory myofibroblastic tumor and other morphologic mimickers.

Myxoid Lipoblastoma and Mimickers on Fine-Needle Biopsy in a Child

Image-guided percutaneous core needle biopsy is a standard and safe procedure for the diagnosis of both solid and hematological malignancies in children. Despite recent improvements, nondiagnosis biopsies persist. Lipoblastoma is a benign adipocytic tumor composed of embryonal fat admixed with mature adipocytes and occurring before the age of 1 year in one-third of cases. Lipoblastoma is usually easily diagnosed, but in some cases, diagnosis may be difficult on percutaneous biopsies, when the lipoblastic component is not well represented or when the tumor contains a prominent myxoid component mimicking other myxoid tumors. We report here a case of lipoblastoma with a predominant myxoid component and discuss differential diagnosis of myxoid lesions of infancy. In such cases, pathologic examination enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic studies, is needed to achieve accurate diagnosis, particularly on fine-needle biopsies.

Rare, risky, recurrent: An enigmatic cutaneous polyp

Myxofibrosarcomas (MFSs) are sarcomas most commonly seen in older patients. These are tumors of deep soft tissue seen in subcutaneous tissue and deep fascia, with frequent muscle involvement. These sarcomas are notorious for recurrences and progression to a higher grade with notable metastatic potential. They are very often under-diagnosed owing to their inherent morphological variability. A case of MFS is presented as a cutaneous, exophytic, polypoidal mass because of its rarity and importance of timely diagnosis, as under-diagnosis may lead to inadequate clearance of tumor, recurrences, metastases and increased mortality.

Spindle cell lipoma mimicking pleomorphic adenoma: A diagnostic challenge on cytology

Spindle cell lipoma (SCL) is a benign neoplasm of mature adipose tissue mostly located in the neck, back, and shoulder region. It is composed of a variable admixture of adipocytes, benign spindle cells, and collagen fibres. While the histopathologic features of SCL are quite characteristic and well described, a cytologic diagnosis of SCL might be challenging. We present a case of a 36-year-old female with a swelling in the left preauricular region since last 6 mo. On fine needle aspiration, a diagnosis of lipomatous pleomorphic adenoma (PA) was rendered because of the presence of benign spindle-shaped cells, adipocytes, and abundant myxoid material. However, on histopathologic examination, the diagnosis was SCL which was confirmed by immunohistochemistry. Preauricular region is a rare site of occurrence of SCL. An acquaintance with its varied cytomorphologic features and a knowledge of its unusual sites of occurrence is essential to prevent its misdiagnosis as other myxoid benign and malignant spindle cell lesions.

Paraplegia in a Domestic Ferret (Mustela Putorius Furo) Secondary to Metastatic Adrenocortical Carcinoma with Myxoid Differentiation

Neurologic disease is a common presentation of domestic ferrets (Mustela putorius furo) with infectious, neoplastic, and traumatic etiologies documented. Adrenocortical neoplasia is also well documented in domestic ferrets, with metastatic lesions rarely described. This case report describes an abnormal presentation of adrenocortical adenocarcinoma with myxoid differentiation and subsequent metastasis to the spinal cord and vertebral bodies, resulting in hind limb paraplegia in an adult spayed female ferret.

Challenges in surgical pathology of adrenocortical tumours

Adrenocortical carcinomas are rare tumours that can be diagnostically challenging. Numerous multiparametric scoring systems and diagnostic algorithms have been proposed to differentiate adrenocortical adenoma from adrenocortical carcinoma. Adrenocortical neoplasms must also be differentiated from other primary adrenal tumours, such as phaeochromocytoma and unusual primary adrenal tumours, as well as metastases to the adrenal gland. Myxoid, oncocytic and sarcomatoid variants of adrenocortical tumours must be recognized so that they are not confused with other tumours. The diagnostic criteria for oncocytic adrenocortical carcinoma are different from those for conventional adrenocortical carcinomas. Adrenocortical neoplasms in children are particularly challenging to diagnose, as histological features of malignancy in adrenocortical neoplasms in adults may not be associated with aggressive disease in the tumours of children. Recent histological and immunohistochemical studies and more comprehensive and integrated genomic characterizations continue to advance our understanding of the tumorigenesis of these aggressive neoplasms, and may provide additional diagnostic and prognostic utility and guide the development of therapeutic targets.

Myxoid and reticular angiomatoid fibrous histiocytoma: a case confirmed by fluorescence in situ hybridization analysis for EWSR1 rearrangement

Angiomatoid fibrous histiocytoma (AFH) is a tumor of intermediate malignancy and undefined lineage, mostly arising in the extremities of young patients. However, AFH may rarely display uncommon clinical and morphologic features, such as older age at presentation, occurrence outside somatic soft tissues and alterations in the architectural patterns, stromal matrix and cytomorphology, causinga great diagnostic challenge for practicing pathologists. Herein, we present a case of AFH with unusual histologic features arising in the right hip of a 37-year-old man. The tumor exhibited a reticular growth pattern and myxoid stroma mimicking myoepithelioma, extraskeletal myxoid chondrosarcoma, or myxoid liposarcoma. The tumor cells focally expressed desmin with a dendritic-like cell process staining pattern and CD68. Fluorescence in situ hybridization analysis confirmed the rearrangement of the EWSR1 gene. This report further expands the clinicopathologic spectrum of AFH and underscores the value of integrating morphologic, immunophenotypic, and molecular findings in the identification of its unusual morphologic variants.

Successful resection of a giant thoracic myxoid liposarcoma

Primary liposarcoma is an extremely rare disease. We report a case of giant thoracic myxoid liposarcoma that occupied the whole left hemithorax and was successfully resected. We discuss the surgical considerations and difficulties encountered, and how we overcome these challenges. This is the third largest thoracic myxoid liposarcoma resection reported, weighing 4 kg.

Myxoid Emboli

Emboli are common clinicopathologic findings. Recognition of the type of arterial emboli could be the first clue to the original source. Emboli with myxomatous changes are rare. Myxoma-like features in mural organizing thrombi have been reported. The most challenging differential diagnosis is between embolic cardiac myxomas and myxomatous thromboemboli. Emboli from sarcomas and arteriosclerotic plaques with myxoid features are also potential pitfalls. There is scarcity of studies focusing on myxoid emboli and their clinical and pathologic importance. We performed a retrospective study over 12 years. We retrieved all of the embolectomy specimens. We histologically screened the emboli for myxoid stroma, myxomatous changes, and mucinous degeneration. We retrieved 12 cases (3%) of myxoid emboli out of 391 embolectomy specimens. We found 4 cases of thromboemboli, 5 cases of atrial myxomas, 2 cases of atheromatous plaques, and a myxoid liposarcoma. The age range was between 35 and 71 years, with a mean age of 51 years. The male-to-female ratio was 3:2. Myxoid thromboemboli and myxomas were large, while atheromatous plaque emboli were small. Myxoid emboli arising from organizing mural thrombi can be histologically confused with cardiac myxomas and vice versa. Myxoid emboli from atheromatous plaque and myxoid sarcomas can mimic embolizing myxomas. Certain histologic features are helpful hints to differentiate between myxoid emboli. In doubtful cases, immunohistochemistry is helpful. Correct histologic recognition of the different types of myxoid emboli helps guide the clinicians to the most likely etiology and appropriate management in occlusive peripheral vascular diseases with clinically unrecognized lesions.

[Subcutaneous myxoid liposarcoma]

Bien que les liposarcomes myxoïdes (LSM) soient la forme la plus fréquente des sarcomes des tissus mous chez l’adulte, leur localisation primaire superficielle est rare. Ainsi, on individualise deux formes de sarcomes: superficiel et profond qui sont distincts non seulement par leur siège et leur fréquence mais aussi par leur pronostic qui est relativement meilleur dans les sarcomes superficiels. Nous rapportons une observation d’un liposarcome sous cutané de la cuisse droite. Le diagnostic a été confirmé histologiquement après une année d’évolution de la symptomatologie clinique. La prise en charge a consisté en une exérèse large suivie d’une radiothérapie locorégionale. L’évolution a été marquée par une rémission complète maintenue après un recul de 32 mois. Nous soulignons, par la présente observation que la rareté des sarcomes superficiels peut être source de retard diagnostic, ce qui pourrait compromettre leur pronostic.

Primary intra-articular sarcoma: a clinicopathological study of 15 cases

AIMS

To assess the clinical and histopathological spectrum of primary intra-articular sarcomas.

METHODS AND RESULTS

Fifteen patients were identified as having primary intra-articular sarcomas and the clinical and pathological features were evaluated. There were nine males and six females who ranged in age from 16 to 84 (mean 44) years. All tumours originated in the knee joint. The pathological diagnoses included: five synovial sarcoma, three extraskeletal myxoid chondrosarcomas, two high-grade myxofibrosarcoma (one conventional, one epithelioid), two undifferentiated pleomorphic sarcoma (one with giant cells) and one each myxoinflammatory fibroblastic sarcoma, conventional hyaline chondrosarcoma, and high-grade myofibroblastic sarcoma. All tumours were treated by segmental resection or amputation. Adjuvant therapy was given in selected cases. Follow-up ranged from 11 to 150 months. Of patients with follow-up, two died of disease; one developed pulmonary metastases after 6 years and was then lost to follow-up. Nine patients were alive and free of disease 12-150 months after diagnosis.

CONCLUSIONS

Primary sarcomas of the joints are very rare and most frequently affect the knee. Our experience indicates that synovial sarcoma and extraskeletal myxoid chondrosarcoma are the most common intra-articular sarcomas.

Fine needle aspiration biopsy of metastatic malignant mesothelioma with myxoid change and signet ring cells: A case report and review of the literature

Malignant mesothelioma (MM) is a rare neoplasm, which is most commonly encountered in cytology through effusion specimens. Fine needle aspiration biopsy of MM, particularly the epithelioid subtype, can be a source of diagnostic difficulty and may mimic sampling of an adenocarcinoma. This is the first case report to demonstrate abundant extracellular myxoid material and numerous intracellular vacuoles, including signet ring cells, in a fine needle aspirate of metastatic MM. A review of the literature for myxoid change and vacuoles in fine needle aspiration biopsies of MM discloses that vacuoles are found in up to 35% of aspirates of MM, but myxoid change is very rare, reported in <5% of the cases. Cytologists should be aware of this rare morphologic pattern of metastatic epithelioid MM.

Invasive urothelial carcinoma with chordoid features of the ureter: a rare entity and review of literature

Invasive urothelial carcinoma (UC) is characterized by some histologic variants that can sometimes lead to diagnostic difficulty. In addition to those described by the World Health Organization. Recently invasive urothelial carcinoma with chordoid features (UCC) has been described as a distinct entity and there are relatively few reported cases in the English-language literature. To date 13 cases of UCC have been reported in 2 case series, respectively in 2009 and 2015. We report the 14(th) case in an 80-year-old female, and to the best of our knowledge this is the second case report of UCC in the ureter. She was admitted to our hospital with macroscopic haematuria and unspecific left lower abdominal pain. Computed tomography scan revealed a soft tissue nodule in the middle of the left ureter. The left nephroureterectomy was performed. Morphologically, 85% areas had acellular myxoid stroma was associated with the neoplastic cells. The neoplastic cells had scant eosinophilic cytoplasm and were arranged into cords closely mimicking chordoma or extraskeletal myxoid chondrosarcoma. 15% areas was typical invasive urothelial carcinoma, and focal areas had transition phenomenon between them. Immunohistochemically, the tumor cells were positive for CK, 34βE12 and p63, but were negative for S100, AFP, CD34, Syn and CgA. The final histopathological diagnosis was UCC of the ureter.

Myxoid soft-tissue neoplasms: comprehensive update of the taxonomy and MRI features. AJR Am J Roentgenol. 2015;204:374-385. [PMID: 25615761 DOI: 10.2214/ajr.14.12888]

OBJECTIVE. The purpose of this article is to review the classification, clinical presentation, and histopathologic and MRI features of myxoid soft-tissue neoplasms. CONCLUSION. MRI is the modality of choice for characterization of myxoid soft-tissue tumors. A combination of imaging features (including certain characteristic signs), clinical features, and patient demographics can help the radiologist in coming to a specific diagnosis or in narrowing down the differential diagnoses.

[Myxoid primitive liposarcoma of the middle mediastinum]

Les liposarcomes “LPS” myxoïdes sont des tumeurs rares, notamment dans leur localisation médiastinale. Nous rapportons un cas d'un liposarcome myxoïde du médiastin moyen, chez un patient de 69 ans, sans passé pathologique particulier et sans signes d'appels respiratoires. Une radiographie thoracique faite lors d'un bilan préopératoire montre un élargissement médiastinal dont le scanner thoracique le rattache à une tumeur hétéro dense, siège de quelques zones de densité graisseuse au niveau du médiastin moyen. Malgré son volume, cette masse parait de contours nets, sans envahissement ni compression des structures adjacentes. La ponction biopsie transpariétale scanno-guidée est compatible avec un liposarcome myxoïde; Une exérèse chirurgicale complète est réalisée. Après 24 mois de surveillance, le patient ne présente pas de signe de récidive. Le LPS myxoïde du médiastin est une entité rarissime et quelques cas sporadiques ont été reportés dans la littérature. La chirurgie parait être le traitement de choix. La radiothérapie et la chimiothérapie gardent leur place dans des indications bien particulières.

Advances in the targeted therapy of liposarcoma

Liposarcoma (LPS) is the most common type of soft-tissue sarcoma. Complete surgical resection is the only curative means for localized disease; however, both radiation and conventional cytotoxic chemotherapy remain controversial for metastatic or unresectable disease. An increasing number of trials with novel targeted therapy of LPS have provided encouraging data during recent years. This review will provide an overview of the advances in our understanding of LPS and summarize the results of recent trials with novel therapies targeting different genetic and molecular aberrations for different subtypes of LPS.

Mucinous urothelial carcinoma of the renal pelvis

Urothelial carcinoma with abundant myxoid stroma is a newly-described and extremely rare entity. Since only very few cases have been reported, there is no consensus on its nomenclature. Microscopic examination revealed invasive urothelial carcinoma with widespread low-grade noninvasive areas. There were focal invasive areas in the neighborhood of the renal parenchyma. Malignant urothelial tumor/cell groups localized in the stroma had abundant myxoid/mucinous background in the invasive areas. The cytoplasm of the tumoral cells was more eosinophilic in these areas and the cells formed small groups and cords. Histochemically, PAS and Alcian Blue were positive in the cytoplasm of the tumoral cells and in the stroma while negative in the non-mucinous areas. Immunohistochemically, the tumoral cells of the mucinous invasive areas diffusely expressed MUC1 and MUC2. We discuss the origin of the mucinous/myxoid stroma, the tumor’s nature and its nomenclature with histochemical and immunohistochemical features.

Chondromyxoid fibroma of zygoma: A rare case report

Chondromyxoid fibroma (CMF) is a rare benign mesenchymal tumor of the bone. Clinically, it is characterized by a lobular growth pattern and histologically by chondroid and myxoid differentiation. The tumor is rare in the craniofacial bones with only 2% of all reported cases. Extragnathic location in the facial skeleton is extremely rare. Most of the cases reported either originate from gnathic sites or in the cranium. A case of CMF in a 3½-year-old male is presented here, which arose from the root of zygomatic arch. A detailed clinical history and histopathological picture of one more case is added to the literature. It is important to document such cases so that better light can be shed on future reviews and conclusions. This shall facilitate better treatment approaches and prognosis. This case is the first reported case of involvement of the zygomatic arch in a pediatric patient.

Parachordoma/myoepithelioma of the kidney: first report of a myxoid mimicry in an unusual location

We report a case of parachordoma (or myoepithelioma) of the right upper kidney in a 56 year-old male patient. Light microscopic features of the tumor exhibited epithelioid, glomoid, and spindle cells with eosinophilic and vacuolated cytoplasm as well as round to oval nuclei. These cells were embedded in a myxoid and hyaline stroma separated by a fibrous tissue with minimal cellular atypia and a few small nucleoli. Immunohistochemically, the tumor cells were immunoreactive for epithelial membrane antigen, calponin, vimentin, S-100, and type-IV collagen. All kidney and adrenal were resected, and the patient was carefully followed up. During the 11 months follow-up, recurrence and metastases were not observed. To our knowledge, this study is the first to document a case of parachordoma/myoepithelioma of the kidney. We add this new case to existing tumors and discuss its distinction from other types.

Reticular and myxoid non-keratinizing nasopharyngeal carcinoma: an unusual case mimicking a salivary gland carcinoma

We present a case of non-keratinizing carcinoma of the nasopharynx (NK-NPC) with an unusual histopathological pattern. The neoplastic cells were arranged in anastomosing cords embedded in a stroma which contained a significant component of alcian blue-positive myxoid substance forming a reticular pattern. These histopathological features gave an initial impression of a salivary gland-type carcinoma. On immunohistochemistry the tumor cells were strongly and diffusely positive for cytokeratins (AE1-3 and 5/6) and p63 and there was strong and diffuse nuclear positivity for Epstein-Barr virus-encoded small RNA on in situ hybridization. This case highlights the histomorphological variability of NK-NPC. Awareness of the histological spectrum of NK-NPC is important in clinical practice and this is not always adequately highlighted in currently used standard textbooks of Head and Neck Pathology.

Odontogenic myxoma

Odontogenic myxoma is a rare intraosseous neoplasm, which is benign but locally aggressive. It rarely appears in any bone other than the jaws. It is considered to be derived from the mesenchymal portion of the tooth germ. Clinically, it is a slow-growing, expansile, painless, non-metastasizing, central tumor of jaws, chiefly the mandible. Here we report the case of a typical odontogenic myxoma in a 26-year-old female patient, which had acquired large dimensions and involved the entire left half of the mandible including the ramus, resulting in a gross facial deformity, within a span of one and a half years.

Myxofibrosarcoma: prevalence and diagnostic value of the "tail sign" on magnetic resonance imaging

OBJECTIVE

Myxofibrosarcoma frequently shows curvilinear extensions of high T2 signal that also enhance on magnetic resonance imaging; these "tails" represent fascial extension of tumor at histopathological examination. This study was performed to determine whether the tail sign is helpful in distinguishing myxofibrosarcoma from other myxoid-containing neoplasms.

MATERIALS AND METHODS

The study group consisted of 44 patients with pathologically proven myxofibrosarcoma; the control group consisted of 52 patients with a variety of other myxoid-predominant tumors. Three musculoskeletal radiologists independently evaluated T2-weighted (and/or short-tau inversion recovery) and post-contrast MR images for the presence of one or more enhancing, high-signal intensity, curvilinear projections from the primary mass. Sensitivity and specificity for the diagnosis of myxofibrosarcoma were calculated for each reader. Interobserver variability was assessed with kappa statistic and percentage agreement.

RESULTS

A tail sign was deemed present in 28, 30, and 34 cases of myxofibrosarcoma and in 11, 9, and 5 of the controls for the three readers respectively, yielding a sensitivity of 64-77 % and a specificity of 79-90 %. The interobserver agreement was moderate-to-substantial (kappa=0.626).

CONCLUSION

The tail sign at MRI is a moderately specific and sensitive sign for the diagnosis of myxofibrosarcoma relative to other myxoid-containing tumors.

Osteotropic cancer diagnosis by an osteocalcin inspired molecular imaging mimetic

BACKGROUND

Although microcalcifications of hydroxyapatite can be found in both benign and malignant osteotropic tumors, they are mostly seen in proliferative lesions, including carcinoma. The aim of this present study is to develop a molecular imaging contrast agent for selective identification of hydroxyapatite calcification in human osteotropic tumor tissues ex vivo and in human osteosarcoma cells in vitro.

METHODS

A bioinspired biomarker, hydroxyapatite binding peptide (HABP), was designed to mimic natural protein osteocalcin property in vivo. A fluorescein isothiocyanate dye conjugated HABP (HABP-19) was utilized to characterize hydroxyapatite on human osteotropic tumor tissue sections ex vivo and to selectively image hydroxyapatite calcifications in human osteosarcoma cells in vitro.

RESULTS

Using a HABP-19 molecular imaging probe, we have shown that it is possible to selectively image hydroxyapatite calcifications in osteotropic cancers ex vivo and in human SaOS-2 osteosarcoma cells in vitro.

CONCLUSION

Hydroxyapatite calcifications were selectively detected in osteotropic tissues ex vivo and in the early stage of the calcification process of SaOS-2 human osteosarcoma in vitro using our HABP-19 molecular imaging probe. This new target-selective molecular imaging probe makes it possible to study the earliest events associated with hydroxyapatite deposition in various osteotropic cancers at the cellular and molecular levels.

GENERAL SIGNIFICANCE

It potentially could be used to diagnose and treat osteotropic cancer or to anchor therapeutic agents directing the local distribution of desired therapy at calcified sites.

Myxoid solitary fibrous tumor: a study of three cases

Limited myxoid areas are usually encountered in solitary fibrous tumor (SFT), but SFT with abundant myxoid stroma has only been reported occasionally. Myxoid SFT is defined as having myxoid changes in 50% or more of the tumor. We review the literature on myxoid SFT and add 3 new cases to those previously described. Microscopically, the lesions were composed of spindle cells arranged in a haphazard or storiform pattern in a cellular and hypocellular myxoid background with thin-walled "staghorn" branching vessels. Atypical features (necrosis, hypercellularity, or increased mitotic figures) were not identified. All cases were positive for CD34 and CD99 and had a benign course with a follow-up ranging from 15 to 70 months. Our review suggests that like classical SFT, myxoid SFT is associated with an indolent clinical course and favorable prognosis. Their recognition is crucial to distinguish a variety of myxoid spindle cell neoplasms with different prognoses and treatment options.