Primary omental smooth muscle tumor in an adult male: a diagnostic dilemma for leiomyoma: a case report

BACKGROUND

The greater omentum comprises peritoneal, adipose, vascular, and lymphoid tissues. Most omental malignancies are metastatic tumors, and the incidence of primary tumors is rare. We report on a prior omental smooth muscle tumor case in an adult male patient.

CASE PRESENTATION

A 54-year-old Japanese male patient with no relevant medical history was diagnosed with an abdominal mass during a routine medical checkup. Subsequent contrast-enhanced computed tomography revealed a mass of approximately 3 cm in size in the greater omentum, and a laparotomy was performed. A 27 × 25 × 20 mm raised lesion was found in the omentum. Microscopically, spindle cells were observed and arranged in whorls and fascicles. Individual tumor cells had short spindle-shaped nuclei with slightly increased chromatin and were characterized by a slightly eosinophilic, spindle-shaped cytoplasm. The mitotic count was less than 1 per 50 high-power fields. The tumor cells showed positive immunoreactivity for α smooth muscle actin, HHF35, and desmin on immunohistochemical examination. The Ki-67 labeling index using the average method was 1.76% (261/14806). No immunoreactivity was observed for any of the other tested markers. We considered leiomyoma owing to a lack of malignant findings. However, primary omental leiomyoma has rarely been reported, and it can be difficult to completely rule out the malignant potential of smooth muscle tumors in soft tissues. Our patient was decisively diagnosed with a primary omental smooth muscle tumor considering leiomyoma. Consequently, the patient did not undergo additional adjuvant therapy and was followed up. The patient was satisfied with treatment and showed neither recurrence nor metastasis at the 13-month postoperative follow-up.

DISCUSSION AND CONCLUSION

We encountered a primary smooth muscle tumor of the greater omentum with no histological findings suggestive of malignancy in an adult male patient. However, omental smooth muscle tumors are extremely difficult to define as benign, requiring careful diagnosis. Further case reports with long-term follow-up and case series are required to determine whether a true omental benign smooth muscle tumor (leiomyoma) exists. In addition, proper interpretation of the Ki-67 labeling index should be established. This case study is a foundation for future research.

Nasal smooth muscle tumor of uncertain malignant potential: A case report

Smooth muscle tumors that cannot be histologically classified as leiomyomas or leiomyosarcomas are defined as smooth muscle tumors of uncertain malignant potential. The location of these tumors in the nose is very rare, and the appropriate surgical extent to manage these neoplasms has not been adequately defined. Here we describe the case of a 16-year-old female adolescent who consulted due to a vascular-like tumor in the right nasal cavity who was successfully treated with intranasal surgery. The histological diagnosis was smooth muscle tumor of uncertain malignant potential. Given that these neoplasms are rare, the uncommon location in the nose, and the lack of evidence indicating the extent of surgery, it is relevant to describe and discuss this clinical case.

Inflammatory Rhabdomyoblastic Tumor: From a Nebulous Smooth Muscle Neoplasm to a Novel Skeletal Muscle Tumor Subtype

Inflammatory rhabdomyoblastic tumor is a recently introduced name for neoplasms currently included in the World Health Organization classification of soft tissue tumors under the rubric inflammatory leiomyosarcoma. Inflammatory rhabdomyoblastic tumor is an excellent example of how surgical pathologists working in conjunction with tumor biologists can greatly improve tumor classification to the benefit of patients. Over the last 28 years, understanding of this entity has undergone a fascinating evolution. This review serves as a summary of the latest findings in inflammatory rhabdomyoblastic tumor research and a diagnostic manual for the practicing surgical pathologist.

Pulmonary Epstein-Barr virus-associated smooth muscle tumor after kidney transplantation: two case reports with review of differential diagnosis

Pulmonary nodules are a common complication in solid organ transplant recipients, and may have various underlying causes, with Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT) being one of them. Given the rarity of this entity, we describe the diagnosis and therapeutic interventions for post-transplant EBV-SMT in two individuals. Both cases involved female patients who were diagnosed with multiple pulmonary nodules 60 months and 116 months, respectively, after receiving living-related kidney transplantation. Pathological examination revealed a spindle cell tumor, with immunophenotype and EBV in situ hybridization supporting the diagnosis of EBV-SMT. After diagnosis, these two patients underwent intervention by decreasing their intake of immunosuppressants. As of the latest follow-up, the patients' lesion size remained stable, and their overall condition was favorable. We also reviewed literature about the morphological and molecular pathological features of EBV-SMT and highlighted the diagnosis and differential diagnosis of pulmonary spindle cell lesions especially in the setting of immunosuppression.

POTENTIAL LIFE PROGNOSTIC MARKER FOR MESENCHYMAL TUMOR RESEMBLING UTERINE LEIOMYOSARCOMA

Benign uterine leiomyoma (U.LMA) and malignant uterine leiomyosarcoma (U.LMS), both uterine mesenchymal tumors, are distinguished by the number of cells exhibiting mitotic activity. However, uterine mesenchymal tumors contain tumor cells with various cell morphologies; therefore, making a diagnosis, including differentiating between benign and malignant tumors, is difficult. For example, cotyledonoid dissecting leiomyoma (CDL) or uterine smooth muscle tumors of uncertain malignant potential (STUMPs) are a group of uterine mesenchymal tumors for which a differential diagnosis is challenging. To date, a standardized classification system for uterine mesenchymal tumors has not yet been established. Furthermore, definitive preoperative imaging techniques or hematological examinations for the potential inclusion of CDL or STUMP in the differential diagnosis have not been defined. Several clinical studies have reported that there is no correlation between biomarker expression and mitotic rate or tumor recurrence. The immunohistochemical biomarkers reported so far cannot effectively help determine the malignant potential of CDL or STUMPs in patients who wish to become pregnant in the future. The establishment of gene expression profiles or detection of pathogenic variants by using next-generation molecular techniques can facilitate disease prediction, diagnosis, treatment, and prognosis. We examined the oncological properties of STUMP in adults using molecular pathological techniques on tissue excised from patients with uterine mesenchymal tumor. In a clinical study conducted by our medical team, the results of gene expression profiling indicated factors that may be associated with malignancy of uterine mesenchymal tumors. We herein describe the problems in diagnosing uterine mesenchymal tumors along with the results of the latest clinical studies. It is expected that the establishment of a diagnostic method targeting the characteristics of mesenchymal tumor cells will lead to the treatment of malignant tumors with a low risk of recurrence and metastasis.

Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP): A Comprehensive Multidisciplinary Update

Background and Objectives: The uterine smooth muscle tumors of uncertain malignant potential (STUMP) are tumors with pathological characteristics similar to leiomyosarcoma, but that do not satisfy histological criteria for leiomyoma. These are problematic lesions with intermediate morphologic features; thus, diagnosis and treatment are difficult. This narrative review aims to review data in the literature about STUMPs, particularly focusing on management and therapeutic options and strategies for women who desire to preserve fertility. Material and Methods: authors searched for "uterine smooth muscle tumor of uncertain malignant potential" in PubMed and Scopus databases, from 2000 to March 2023. Pertinent articles were obtained in full-text format and screened for additional references. Only articles in English language were included. Studies including full case description of patients with histopathological diagnosis of STUMP in accordance with Stanford criteria were included. Results: The median age was 43 years old. Symptoms are similar to those of leiomyomas, with a mean diameter of 8.0 cm. Total hysterectomy with or without bilateral salpingo-oophorectomy is the standard care for women if fertility desire is satisfied. Myomectomy alone can be considered for young patients. Although these tumors have not a high malignant potential, several studies described recurrence and metastases. Conclusions: STUMPs are complex uterine smooth muscle tumors, with a rare but reasoned clinical-diagnostic management. Considering the high clinical and histological complexity of these tumors, high level of expertise is mandatory.

Management of a giant uterine smooth muscle tumor of uncertain malignant potential in a 32-year-old woman: case report and review of the literature

Uterine smooth muscle tumors of uncertain malignant potential (STUMP) represent a group of rare uterine smooth muscle tumors not diagnosed unequivocally as benign or malignant. To data, diagnostic criteria, malignant potential, surgical management, and follow-up of these neoplasms remain controversial. Considering that STUMP and leiomyoma are not significantly different in terms of clinical presentation and preoperative sonographic characteristics, it might be difficult to distinguish between the two affections prior to pathological confirmation at surgery. All cases should be managed by multidisciplinary tumor teams and patients' follow-up should comprise consultation with a gynecologic oncologist and a close surveillance because of the possibility of recurrence or metastasis. We present the case of a 32-year-old nulliparous woman admitted to our gynecology clinic. She was asymptomatic and only complained an increase in abdominal volume started during the past 6 months. A transabdominal and transvaginal pelvic ultrasound revealed a large heterogeneous tumor mass measuring 190×163 mm, color score 2, expanded in the left iliac fossa, suspected for benign uterine myoma. Subsequent magnetic resonance imaging confirmed a large pelvic-abdominal tumor located near the left posterior-lateral uterine wall with areas of necrosis, suggestive of subserosal leiomyoma with cystic degeneration. The patient underwent a median longitudinal laparotomy for excision of the pelvic mass. The patient was normally discharged five days after surgery in good health conditions. The final histological examination was compatible with STUMP. At present, the patient has had no relapses or metastases and she is undergoing follow-up.

Fumarate Hydratase Deficiency Should be Considered in the Differential Diagnosis of Uterine and Extrauterine Smooth Muscle Tumors of Uncertain Malignant Potential (STUMP)

Fumarate hydratase-deficient leiomyomas (dFH leiomyomas) often display atypical pathologic features yet exhibit a benign clinical course. Recent data suggest that dFH leiomyomas may be misclassified as smooth muscle tumors of uncertain malignant potential, a category that encompasses a heterogenous subgroup of uterine neoplasms with smooth muscle differentiation and atypical features that impart ambiguity regarding their expected clinical behavior. dFH leiomyomas can be seen in the context of hereditary leiomyomatosis and renal cell carcinoma syndrome or in the sporadic setting. In this retrospective study, we sought to examine the prevalence and clinicopathologic characteristics of dFH leiomyomas in 48 tumors previously diagnosed as smooth muscle tumors of uncertain malignant potential from 38 patients. Of these 48 tumors, 3 (6.3%) occurring in 2 patients were found to be deficient for FH by immunohistochemistry, including 1 uterine and 2 extrauterine (abdominopelvic) tumors. The 3 tumors showed histologic features typical of dFH leiomyomas, including hemangiopericytoma-like vessels, edema, macronucleoli, and atypia. Neither patient developed recurrent leiomyomas or renal cell carcinoma, and both were alive without disease at last follow-up. Our data suggest that dFH leiomyomas should be considered in the differential diagnosis of smooth muscle tumors of uncertain malignant potential, even in the context of extrauterine disease. Identification of FH deficiency in these tumors supports their classification as dFH leiomyomas despite their atypical morphologic features and/or clinical presentation. Importantly, detection of dFH in these cases may identify women at increased risk for hereditary leiomyomatosis and renal cell carcinoma who would benefit from genetic counseling and consideration for FH germline testing.

[Practical diagnostic aspects of uterine leiomyosarcoma in the context of the 2020 WHO classification]

The 2020 WHO Classification defines the spindle cell, epithelioid, and myxoid variants as subtypes of uterine leiomyosarcomas (LMS). Presence of cellular atypia (size variation of polymorphic nuclei > 2-3:1), tumor cell necroses, and mitotic count (usually ≥ 10 MF/10 HPF) are still the key features for diagnostic separation from uterine leiomyomas. Preanalytic variables, staining quality, as well as intralesional geographic distribution may affect the mitotic count. Smooth muscle tumors of uncertain malignant potential (STUMP) still exist as a not yet well-characterized diagnostic entity. Immunohistochemical stains against p16, p53, Ki-67, and WT‑1 may aid differential diagnosis in selected cases. Diagnostic molecular pathology is not yet relevant for diagnosis.

Epithelioid Leiomyosarcoma of the Uterus: Modern Outcome-based Appraisal of Diagnostic Criteria in a Large Institutional Series

Epithelioid leiomyosarcoma of the uterus is rare and poorly understood. Herein, we characterize a large institutional series of epithelioid leiomyosarcomas aiming to define outcome-determinant diagnostic pathologic features. We also retrieved epithelioid smooth muscle tumors of unknown malignant potential and evaluated a consecutive cohort of leiomyomas for epithelioid subtypes. Of a total of 1177 uterine leiomyosarcomas, 81 (7%) were categorized as epithelioid after review. Epithelioid leiomyosarcoma was strictly defined as having round to polygonal cells with visible pink cytoplasm and round to ovoid nuclei in ≥50% of the tumor volume. Average age was 55 years (range: 26 to 81 y). Median tumor size was 11 cm; tumor was >5 cm in 93% of subjects; 47% were stage 1 at presentation. An infiltrative tumor border was observed, grossly and/or microscopically, in 89% of cases; necrosis was noted in 80%, and vascular invasion in 47%. Mitotic count in 2.4 mm2 (totalling 10 high-power fields, each field 0.55 mm in diameter) ranged from 3 to 100 (median: 26). All cases had moderate, severe or highly pleomorphic atypia. All cases had 2 or 3 of the following: necrosis, at least moderate atypia and ≥4 mitoses in 2.4 mm2. Immunohistochemistry revealed frequent expression of smooth muscle markers including SMA (96%), desmin (95%), and caldesmon (81%). HMB45 and Melan-A were negative in 92% and 100% of cases, respectively. Estrogen and progesterone receptors were expressed by 65% and 54% of tumors, respectively. Follow-up information was available in 68 subjects (median: 23 mo, range: 1 to 254); cancer-related death occurred in 63%, and an additional 15% had recurrent or metastatic disease at last follow-up. Disease-specific survival was shorter in epithelioid leiomyosarcoma patients (median: 44  mo; 35% at 5-y) than in a matched cohort of nonepithelioid leiomyosarcoma (median: 55 mo; 46% at 5-y) (P=0.03). Three epithelioid smooth muscle tumors of unknown malignant potential were evaluated, all <5 cm in size and with atypia and/or irregular borders but mitotic count below the threshold for malignancy. Two of these had follow-up available, which was uneventful. Of 142 consecutive leiomyomas assessed, none had epithelioid morphology as defined. Epithelioid leiomyosarcoma is an aggressive neoplasm, sometimes with a remarkably low mitotic count. In the setting of an epithelioid smooth muscle tumor of the uterus, we postulate that the diagnosis of malignancy is made in the presence of ≥2 of the following: moderate or severe atypia, ≥4 mitoses/2.4 mm2 and tumor cell necrosis. In their absence, the finding of tumor size ≥5 cm, vascular invasion, infiltrative edges or atypical mitoses should be treated with caution, and designation as of at least uncertain malignant potential is warranted.

Intraoperative Frozen Section Biopsy of Uterine Smooth Muscle Tumors: A Clinicopathologic Analysis of 112 Cases With Emphasis on Potential Diagnostic Pitfalls

Frozen sections of uterine smooth muscle tumors are infrequently required, and related diagnostic difficulties are seldom discussed. We analyzed the clinicopathologic features of 112 frozen sections of uterine smooth muscle tumors and determined the accuracy, reasons for deferrals, and causes of interpretational errors. Most patients (median age, 45 y) presented with pelvic mass symptoms (53%). The main reasons for a frozen section examination were an abnormal gross appearance including loss of the usual whorled pattern of leiomyoma (36 cases, 32.1%), and intraoperative discovery of an abnormal growth pattern and extrauterine extension of a uterine tumor (28 cases, 25%). There were 9 leiomyosarcomas and 103 leiomyomas, including 18 benign histologic variants. An accurate diagnosis of malignancy was achieved in all leiomyosarcomas, with the exception of a myxoid leiomyosarcoma. In 99 cases (88%), the frozen section diagnosis concurred with the permanent section diagnosis (false positives, 0.9%; false negatives, 0%). Misinterpretation of stromal hyalinization as tumor cell necrosis in a leiomyoma with amianthoid-like fibers was a major discrepancy. Two minor discrepancies did not lead to a change in management. The diagnosis was deferred in 10 cases (8.9%) because of stromal alterations, unusual cellular morphology, uncertain type of necrosis, and abnormal growth patterns. Thus, although various stromal and cellular alterations can cause diagnostic uncertainty, leading to deferrals, frozen section diagnosis of uterine smooth muscle tumors has a high accuracy rate. While a definitive frozen section diagnosis of malignancy may be made when there is unequivocal atypia, indisputable mitotic figures, and tumor cell necrosis, it is important to remember that nonmyogenic mesenchymal tumors may also mimic uterine smooth muscle tumors. In a frozen section setting, it would be sufficient to issue a diagnosis of "malignant mesenchymal tumor." For tumors that do not meet the criteria for malignancy, issuing a frozen section diagnosis of "atypical mesenchymal tumor and defer the histologic subtyping to the permanent sections" is appropriate.

[Epstein-Barr virus-associated smooth muscle tumor in a girl]

A girl, aged 7 years, was admitted due to pain in both lower limbs for more than one year. Lumbar MRI showed soft tissue masses in the paravertebral region. Cerebral MRI showed nodular masses in the cavernous sinus at both sides. Chest CT showed high-density nodules in the outer basal segment of the right inferior lobe and the anterior segment of the left upper lobe of the lung. Biopsy of lumbar lesions showed Epstein-Barr (EB) virus-related smooth muscle tumor. Genetic testing showed a de novo mutation, c.725_730delAGAGTA (p.K242_S243del), in the ITK gene. The masses in the lumbar vertebra were removed by surgery, and then the pain in both lower limbs disappeared. This article reports a case of EB virus-related smooth muscle tumor with a deletion mutation in the ITK gene, which provides experience for the diagnosis and treatment of this disease.

PHENOTYPIC CHARACTERISTICS OF RELAPSED LEIOMYOMA AND SMOOTH MUSCLE TUMORS OF UNCERTAIN MALIGNANCY POTENTIAL IN REPRODUCTIVE WOMEN

Uterine leiomyoma represents the most common pelvic tumor in females, including numerous histological subtypes, from which smooth muscle tumors of uncertain malignancy potential (STUMP) represents the diagnostic challenge. On the other hand, the study of the relapse risk markers after laparoscopic myomectomy is of high interest. We investigated the molecular phenotype of different types of leiomyoma after hysterectomy or laparoscopic surgery in reproductive and menopausal women. Standard immunohistochemistry was used to detect proliferation markers Ki67 and cyclin D1, apoptotic markers Bcl2 and Cas3, and ER and PR. The results of our study indicated that ER expression is significantly higher in relapsed leiomyoma, compared to control group. In addition, relapsed leiomyomas are characterised with high proliferation and apoptotic index. With regard to STUMP despite histological homogeneity, this entity is characterised with the presence of three distinct molecular subtypes, based on proliferation and apoptotic marker expression, which should be used as diagnostic aid in these tumors.

Epstein-Barr virus associated hepatic smooth muscle tumor in a patient with acquired immunodeficiency syndrome: A case report

INTRODUCTION

Epstein-Barr virus (EBV) associated smooth muscle tumors (SMTs) usually present under the condition of immunosuppression, including congenital immunodeficiency syndrome-SMT, post-transplantation-SMT and HIV-SMT. HIV-SMTs are most likely to invade the central nervous system, followed by the liver, lungs, and other locations. Many laboratory techniques, including serological techniques, polymerase chain reaction and immunohistochemistry (IHC), are employed to determine the aetiologies of these tumours. With respect to therapy, surgical resection is the main treatment. In patients with immunodeficiency, improving immune status is significant for defending against other viruses. We describe a case of the primary focus of SMT in the liver of HIV-positive patient without any metastasis.

PATIENT CONCERNS

A young male HIV-positive patient complained of fever and abdominal pain for 2 months.

DIAGNOSIS

IHC of liver tissue confirmed the finding: EBV-related smooth muscle tumor.

INTERVENTIONS

Given the patient's general condition, he was not a suitable candidate for surgical resection. He was given antibiotics, antifungal agents and EBV-directed agents to control infection as well as highly active antiretroviral therapy to enhance the immunity.

OUTCOMES

The patient's symptoms improved. He was discharged.

CONCLUSIONS

In conclusion, EBV-related HIV-SMTs is a rare neoplasm found in the liver among immunodeficient patients. This case highlights that a variety of examinations such as IHC for smooth muscle markers (smooth muscle actin and desmin) and EBER, as well as polymerase chain reaction for EBV DNA should be done when diagnoses are ambiguous.

Immunoexpression of progesterone receptor, epithelial growth factor receptor and galectin-3 in uterine smooth muscle tumors

Uterine smooth muscle tumors constitute a spectrum of neoplasms. Diagnosis of leiomyomas (LMs) is usually straight forwards; however, atypical leiomyomas (ALMs) and smooth muscle tumors of uncertain malignant potential (STUMPs) have overlapping features and need to be distinguished from leiomyosarcoma. To evaluate progesterone receptor (PR), epithelial growth factor receptor (EGF-R), and galectin-3 expression in LMs, ALMs, STUMPs, and leiomyosarcomas and to assess their possible role in differentiating those tumors. Immunoexpression of EGF-R, PR, and galectin-3 were studied in 44 cases of uterine smooth muscle tumors through retrospective study. Studied cases included 20 LM, 9 ALM, 5 STUMP, and 10 leiomyosarcomas. A semiquantitative score was used to evaluate immunohistochemical staining. EGF-R overexpression was detected in leiomyosarcomas while a lack of or reduced EGF-R expression was observed in the nonsarcomatous group (LMs, ALMs, and STUMPs) with a highly significant difference. On the contrary, there was weak or negative PR staining in leiomyosarcomas compared to intense PR expression in the nonsarcomatous group with a highly significant difference. Meanwhile, galectin-3 was downregulated in leiomyosarcomas compared to the nonsarcomatous group with a significant difference. Correlation analysis revealed negative correlation between EGF-R and PR expression with significant statistical results while correlation of galectin-3 with EGF-R and PR showed insignificant statistical results. Immunoexpression of EGF-R, PR, and galectin-3 could help differentiate challenging cases of uterine smooth muscle tumors. Further studies are recommended to investigate interactions between EGF-R, PR, and galectin-3 and to plan new therapeutic strategies.

Ovarian leiomyoma with myxoid stroma

Ovarian smooth muscle tumours are rare. Notable myxoid change in smooth muscle tumours is uncommon, and raises diagnostic issues that need to be considered on evaluating a spindle cell lesion with notable myxoid change. There is only one case of myxoid leiomyoma of the ovary previously reported. We here report a case of ovarian leiomyoma with areas of myxoid stroma and discuss the relevant differential diagnosis and histological features to be assessed in such a lesion.

Concomitant Epstein-Barr Virus-associated smooth muscle tumor and granulomatous inflammation of the liver

Epstein-Barr Virus-associated smooth muscle tumor (EBV-SMT) is a rare mesenchymal tumor typically seen in immunocompromised patients. Here, we report a case of EBV-SMT and associated granulomatous inflammation in the liver of a 32-year-old man with history of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). To our knowledge, an association of these two lesions has not been previously reported. We review the literature and discuss pathogenesis, differential diagnosis and immunohistochemical (IHC) stains helpful for the diagnosis of this rare entity. Finally, we consider possible explanations for the concomitant presence of these lesions.

Uterine smooth muscle tumors of uncertain malignant potential: analysis of diagnoses and therapies illustrated by two case reports

Uterine smooth muscle tumors of uncertain malignant potential, or STUMP, form a rare group of tumors that fall neither into the benign nor malignant categories. Two cases are reported, describing diagnosis, known prognostic factors, and therapy. In contrast to leiomyomas and leiomyosarcomas, many uncertainties still exist concerning prognosis and postoperative management of STUMP, because of their rarity. Diagnosis is usually not made preoperatively, but by postoperative anatomo-pathological examination. There are histological and immunohistochemical factors that could be associated with a worse prognosis, but scientific evidence is insufficient. Most cases show a low risk of recurrence, although individual risk is unpredictable. Recurrences mostly occur after a long disease-free interval. A conservative approach with strict long-term clinical follow-up is therefore indicated. Further research must be conducted to identify surgical procedures that have a higher risk for recurrence. After a laparoscopy, where the specimen was morcellated, the possibility of peritoneal spread and the difficulty in examining section margins, need to be taken into account. Further treatment therefore needs to be individualized.

[Uterine smooth muscle tumors--direction of differentiation and morphological features]

Uterine smooth muscle tumors /USMT/ are the most common tumors of the female reproductive system. The main aim of the clinical histological classification and the grading of MGMT is to predict their progression. The diagnosis of USMT has of the following stages: the determination of the direction of differentiation of the tumor and the defining the morphological features (the mitotic index, the tumor necrosis and the cellular atypia). In each of them there are specific problems. This indicates, that the USMT are therapeutic and clinical challenge.

Mixed stromal and smooth muscle tumours of the uterus: a report of two cases

Mixed stromal and smooth muscle uterine tumours, defined as those containing at least 30% of each component as seen by routine light microscopy, are rare. This report describes the morphological features of two such tumours diagnosed in 44-year-old and 50-year-old females complaining from recurrent uterine bleeding that was unresponsive to medical treatment. Morphological and immunohistochemical evaluations were performed, and a final diagnosis of mixed endometrial stromal nodule and smooth muscle tumour of the uterus was rendered in both cases.

Immunohistochemical analysis in the diagnosis of uterine myometrial smooth muscle tumors

Uterine myometrial smooth muscle tumors sometimes raise concerns related to their histopathological typing, and that especially for benign entities with areas of atypia. In this study, we analyzed a group of myometrial smooth muscle tumors in what it regards their differential diagnosis utilizing a panel of antibodies consisting of α-SMA, Ki-67, p16, p53, PR and bcl-2. The study included a total of 16 cases of cellular leiomyomas, five cases of atypical leiomyomas and six of leiomyosarcomas, which were all analyzed for age, risk factors, mitotic activity, cellular atypia and tumor staging. In cases of cellular leiomyomas, the immunophenotype was characterized by high expression of PR and bcl-2 and low expression of p53 and Ki-67. For atypical leiomyomas, PR, bcl-2 and p53 expression levels were highly compared with low levels of p16 and Ki-67. Leiomyosarcomas immunophenotype was characterized by high expression values of Ki-67, p16 and p53, and decreased levels of PR and bcl-2. The study indicated specific immunophenotypes among the uterine myometrial smooth muscle tumors analyzed. The antibody panel used here might be a useful for the complementary histopathological analysis of myometrial leiomyomas and leiomyosarcomas.

[Uterine smooth muscle tumors--determination of clinical behavior and classification]

The establishment of the clinical behavior of uterine smooth muscle tumors /USMT/ is an essential stage of modern diagnostics. There are significant differences in the criteria determining the malignant potential of smooth muscle gynecological tumors. Generally USMT generating diagnostic problems are classified into: clinically benign tumors; clinically malignant tumors with benign morphological features; smooth muscle tumors of uncertain malignant potential (SMTUMP) and lesions whose smooth muscle differentiation is not obvious. The knowledge in this area is essential for an adequate therapeutic approach.

CD147 expression in uterine smooth muscle tumors, and its potential role as a diagnostic and prognostic marker in patients with leiomyosarcoma

OBJECTIVE

To investigate the role of CD147 expression in uterine smooth muscle neoplasms, as a potential diagnostic and prognostic marker in patients with leiomyosarcoma (LMS).

STUDY DESIGN

We investigated CD147 protein expression in uterine smooth muscle tumor samples from patients diagnosed with leiomyoma (n = 22), atypical leiomyoma (BLM) (n = 5), smooth muscle tumor of uncertain malignant potential (STUMP) (n = 14), and LMS (n = 22). The intensity and extensity of immunohistochemical staining were compared to determine its potential role in differential diagnosis. Spearman's rank correlation tests were performed to determine the relationship between CD147 expression and prognostic clinical and pathological criteria in the patients with LMS.

RESULTS

CD147 was strongly expressed in 81.8% (n = 18) of the LMS tissue samples. In fact expression of CD147 in LMS tissues was significantly higher than that of the three other uterine smooth muscle tumor types (p = 0.000). However, high CD147 expression was found in only one BLM sample and one STUMP sample. Furthermore, CD147 percent expression positively correlated with Ki67 percent expression (r = 0.466, p<0.05) and mitotic index (r = 0.554, p<0.05), respectively.

CONCLUSION

Our results suggest that immunohistochemistry may be a helpful tool in determining whether CD147 is a useful marker in the differential diagnosis of certain uterine smooth muscle tumors. CD147 may also have prognostic value for patients with LMS. Yet, in order to determine the extent of this potential marker's utility as a diagnostic and prognostic indicator, a larger randomized multicenter study must be performed.

[Primary smooth muscle tumor in the male reproductive system: a report of 5 cases and review of the literature]

OBJECTIVE

To systematically study the clinical diagnosis and treatment of smooth muscle tumor in the male reproductive system.

METHODS

We analyzed the ultrasonographic features, pathological findings, treatment strategies and postoperative follow-up results of 5 male patients with smooth muscle tumor in the reproductive system, and reviewed other relevant literature.

RESULTS

Compared with leiomyoma, leiomyosarcoma exhibited stronger mixed echoes than the testis at ultrasonography, typical mitotic phase (> or = 2/10 HP) of tumor cells at HE staining, and significant expressions of HIF-1alpha and Glut-1 at immunohistochemistry. No relapse was observed in the 2 cases of leiomyoma during the 10-year follow-up after simple tumor resection, nor were recurrence and metastasis in another 3 cases of leiomyosarcoma during the first year after radical surgery without combined radio- and chemo-therapy.

CONCLUSION

Primary smooth muscle tumor of the male reproductive system is difficult to be diagnosed. Ultrasonography can help to preliminarily screen leiomyosarcoma. For those with possible leiomyosarcoma, preoperative MRI and intraoperative frozen sectioning examinations are recommended for the possibility of lymphatic metastasis. Postoperative radiotherapy and chemotherapy should be chosen cautiously for those confirmed with leiomyosarcoma by pathological examination.

Epstein-Barr Virus associated primary intracranial smooth muscle tumor in HIV positive patient: case report and review of the literature

The authors report a case of HIV-positive patient with primary intracranial smooth muscle tumor Evidence of Epstein-Barr Virus (EB V) infection in this tumor is proven by in situ hybridization for EBV-encoded RNA (EBER). Review of the literature shows that the occurring of smooth muscle tumor at intracranial site is extremely rare and most cases are HIV-infected patient. It also shows an association with EBV infection.

Subcutaneous angioleiomyoma of the nasal tip. Report of a rare case

Angioleiomyoma is a rare benign tumor of smooth muscle origin. It has been reported in many anatomical sites, but it is very rare in the nose. This article describes the case of a 46-year-old woman, with a subcutaneous vascular leiomyoma of the nasal tip. She reported a small painless mass. The skin which was covering it became strongly erythematous at high temperatures, with an annoying increase of the sensitivity. There are no specific imaging techniques capable of characterizing the vascular leiomyoma, however sonography represents an excellent modality for initial evaluation of this kind of lesion. We chose excision with an open rhinoplasty approach for treatment of the lesion. Obvious and disfiguring scars do not remain with this surgical approach. The patient had immediate and complete relief of her symptoms, the aesthetic result is very good and her satisfaction is complete.

Uterine smooth muscle tumors of uncertain malignant potential: diagnostic challenges and therapeutic dilemmas. Report of 2 cases and review of the literature

Morphologically, there exist variants of uterine smooth muscle tumors that cannot be clearly interpreted and classified as benign or malignant. Because their behavior and clinical prognosis is also uncertain, the World Health Organization has termed these "smooth muscle tumors of uncertain malignant potential" (STUMP). Herein we describe 2 cases, present a review of the literature, and highlight the diagnostic challenges and therapeutic dilemmas associated with uterine STUMP in myomectomy specimens from women who wish to maintain or enhance their fertility. The clinical course of residual STUMP remains speculative.

Epstein-Barr virus associated smooth muscle tumors. Synchronous liver and lung involvement

Epstein-Barr virus associated smooth muscle tumors (EBV-SMT) are rare neoplasms that can occur in various anatomical locations. They mainly affect immunocompromised patients, and their clinical presentation is variable depending on size and organ involvement. They can pose diagnostic challenges, therefore if they are not considered in the differential diagnosis, they can be definitely misdiagnosed. Synchronous and multifocal involvement has been reported. Although malignant behavior maybe rarely seen; most behave in a benign fashion with favorable clinical outcome. We herein report an unusual case of synchronous EBV-SMT that occurred in the lung and liver in a 44-year-old female patient 7 years after renal transplantation. Both lesions were histologically examined revealing benign appearing spindle cell neoplasm that was positive on immunohistochemical staining for smooth muscle actin, desmin, and caldesmon with strong nuclear staining for EBV RNA by in situ hybridization. A brief pertinent literature review and discussion of EBV-SMT pathogenesis is offered.

Myxoid mixed low-grade endometrial stromal sarcoma and smooth muscle tumor of the uterus. Case report

We report the case of a 73-year-old female with myxoid mixed low-grade endometrial stromal sarcoma and smooth muscle tumor of the uterus. Grossly, the tumor sized 130 x 130 x 100 mm involved the uterine corpus almost in its entirety. Histologically, the tumor consisted of two cell types. In some areas, the tumor cells showed typical features of endometrial stromal tumors and resembled stromal cells of proliferative endometrium. In other areas, however, the tumor showed smooth muscle features and consisted of larger mostly epitheloid cells with a moderate amount of cytoplasm. In all areas, myxoid changes and multiple hyalinizing giant rosettes were present. The tumor infiltrated the myometrium in a pattern typical of low-grade endometrial stromal sarcoma. Immunohistochemically, the tumor cells showed expression of vimentin, estrogen and progesterone receptors and variable expression of CD10, α-smooth muscle actin, desmin, h-caldesmon, and cytokeratin AE1/AE3. Other markers examined including CD99, α-inhibin, cytokeratin CAM5.2, S-100 protein, and HMB45 were negative. To the best of our knowledge, mixed low-grade endometrial stromal and smooth muscle tumor with myxoid changes has not been described to date.

Multicentric hepatic EBV-associated smooth muscle tumors in an AIDS patient: a case report, investigation of mTOR activation and review of the literature

Epstein-Barr virus (EBV) - associated smooth muscle tumors (EBV-SMT) are a rare, recently recognized distinct group of mesenchymal tumors that develop exclusively in patients with immunosuppression. It is believed that tumorigenesis is, at least in part, through the activation of the Akt/mammalian target of rapamycin (mTOR) signal pathway. We describe the clinicopathologic and immunohistochemical features of a multifocal hepatic EBV-SMT in a 34-year-old acquired immunodeficiency syndrome (AIDS) patient and investigate the activation status of the mTOR signal pathway in this tumor. In addition, we provide a review of the literature on the clinicopathologic findings of hepatic EBV-SMT in adult AIDS patients, and discuss their biologies and possible therapeutic strategies.

Uterine smooth muscle tumors of uncertain malignant potential: a case presentation

A 42-year-old virgin woman was admitted to our clinic with increasing menorrhagia and dysmenorrhea for several months. A pelvic ultrasound scan showed a 9 × 7 cm heterogeneous mass in the uterine cavity. Pelvic magnetic resonance imaging showed a large non-homogeneous tumor mass measuring 97 × 56 mm in the uterine cavity. After intravenous contrast material, cystic necrotic areas with marked contrast enhancement were observed in the solid lesion. Tumor markers were all within normal ranges. The patient underwent laparotomy, and total hysterectomy and bilateral salpingo-oophorectomy were performed. Our case was diagnosed as uterine smooth muscle tumor of uncertain malignant potential (STUMP). The patient was put on a close clinical follow-up schedule, and is doing well without recurrence in 2 years later. Patients with STUMP should be counseled regarding the potential for recurrence as leiomyosarcoma, and may require closer surveillance than a yearly examination and may need a consultation with a gynecologic oncologist.

A clinicopathologic study of uterine smooth muscle tumours of uncertain malignant potential (STUMP)

INTRODUCTION

The clinical management of Smooth Muscle Tumours of Uncertain Malignant Potential (STUMPs) remains controversial because little is known about the natural history of these tumours and pathological classifications do not correlate well with clinical outcomes and therefore cannot direct management. The objective of this study was to review a single institution's experience with STUMP and recommend a rational clinical approach to the management of patients with this histological diagnosis.

MATERIALS AND METHODS

A systematic review of all diagnoses of STUMP and leiomyosarcoma from the gynaecologic oncology and pathology databases between January 1970 and February 2006.

RESULTS

A total of 18 diagnoses of STUMP and 72 diagnoses of Ieiomyosarcoma were made during the study period. None of these 72 cases of leiomyosarcoma had a prior diagnosis of STUMP. There were no recurrences in the 18 cases of STUMP with all 18 cases being registered as disease-free after 5 years.

CONCLUSIONS

We recommend that patients with a diagnosis of STUMP be expectantly managed given the low likelihood of leiomyosarcomatous transformation, the lack of any evidence that adjuvant treatments result in better long-term outcomes and that recurrences are amenable to surgical resection with good outcomes.

Revision of gastrointestinal mesenchymal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal (GI) tract. The advent of target therapy (imatinib mesylate) for GISTs increases the importance of pathologic diagnosis. The previous diagnosis with smooth muscle tumor (leiomyoma or leiomyosarcoma) and nerve sheath tumor (schwannoma) become GISTs after the study with CD117 immunohistochemistry accompanying conventional histologic study in many series.

OBJECTIVE

To identify the incidence of GISTs in the patients who were previously diagnosed with smooth muscle or nerve sheath tumors. The histology and immunoreactivity of both newly found and previously diagnosed with GISTs are also studied

MATERIAL AND METHOD

A retrospective database identified all patients seen from 1998 to 2006. Patients with mesenchymal tumors of the GI tract and intraabdominal extragastrointestinal tract were selected, 53 cases in total. Clinical and pathological data, treatment, and outcome were analyzed

RESULTS

After revision, the total number of GISTs is 42 cases. There were 33 cases previously diagnosed with leiomyosarcoma that became the diagnosis with GISTs (31 cases or 93.9%), due to CD117 positivity. Most of GISTs cases had spindle cell type (26 cases, 61.9%) and only the colon and omentum had predominant mixed cell type.

CONCLUSION

GISTs are the most common mesenchymal neoplasm of the stomach and small intestine and are relatively less frequent at other gastrointestinal sites. An increasing awareness of their histologic, immunophenotypic, and molecular features coupled with an evolving understanding of their histogenesis is facilitating our ability to identify these tumors.

Incidental seminal vesicle smooth muscle neoplasm of unknown malignancy following robotic-assisted laparoscopic prostatectomy

Primary soft tissue sarcomas of the genitourinary tract are rarely seen, especially in the seminal vesicle. While sarcomas have been reported in the seminal vesicle, this is the first report of a smooth muscle neoplasm, of uncertain malignant potential, involving the seminal vesicle. The finding was incidental, following robotic-assisted radical retropubic prostatectomy for prostate cancer. To our knowledge, this is also the first report of a primary seminal vesicle tumor found following radical prostatectomy. A clinical case review and a brief review of the literature are presented.

Diagnostic criteria for uterine smooth muscle tumors: leiomyoma variants associated with malignant behavior

OBJECTIVE

To determine the prognostic accuracy of current diagnostic criteria for uterine smooth muscle tumors.

STUDY DESIGN

Cases of uterine leiomyosarcoma (LMS) treated from 1976 to 1999 were analyzed retrospectively. Uterine LMS specimens were reevaluated using current criteria by a pathologist specializing in gynecologic diseases. Kaplan-Meier survival curves were evaluated.

RESULTS

Specimens were available from 67 patients diagnosed with uterine LMS. On rereview, only 47 specimens were thought to represent uterine LMS. The 20 other patients were deemed to have leiomyomas or leiomyoma variants, including 13 cellular leiomyomas, 5 atypical leiomyomas and 2 leiomyomas. Median survival for patients with uterine LMS was 2.1 years. (Ninety-seven percent of disease-specific deaths occurred within 6 years after the diagnosis.) With leiomyoma variants, median survival was > 25 years. Among these 18 women were 3 disease-specific deaths (all > 6 years after diagnosis).

CONCLUSION

Diagnostic criteria for uterine smooth muscle tumors require continued refinement. A small but significant number of patients diagnosed with leiomyoma variants will die of the disease. In contrast to the aggressive behavior of uterine LMS, disease-specific deaths attributed to leiomyoma variants occurred later. With this potential for delayed recurrence, these patients warrant close clinical surveillance.

Epstein-Barr virus–associated smooth muscle tumor presenting as a vulvar mass in an acquired immunodeficiency syndrome patient: a case report

Smooth muscle tumors in immunocompromised patients have a strong association with Epstein-Barr virus (EBV) infection. EBV-associated smooth muscle tumors (EBV-SMT) are considered as a distinct group of smooth muscle tumors with different clinicopathologic features from conventional smooth muscle tumors. A 31-year-old female patient presented with a 2-cm mass at the left labium majus, the clinical diagnosis of which was a Bartholin lesion. She had acquired immunodeficiency syndrome diagnosed 29 months before. Excisional biopsy revealed a cellular tumor composed of round- to spindle-shaped cells with mild to moderate nuclear atypia. The tumor cells were immunoreactive for smooth muscle actin and muscle actin (HHF-35). Evidence of EBV infection was confirmed by in situ hybridization for EBV-encoded small RNA-1. To our knowledge, this is the first case of EBV-SMT presenting as a vulvar mass. EBV-SMT should be included in the differential diagnoses of mesenchymal tumor in patients with immunosuppression and in the differential diagnoses of smooth muscle tumor in uncommon sites, including the vulva.

Expression of cyclooxygenase-2, c-kit, progesterone and estrogen receptors in uterine smooth muscle tumors: differential diagnosis

We examined the expression pattern of cyclooxygenase-2 (COX-2) and c-kit in uterine smooth muscle neoplasms and tried to determine the role of these markers in differential diagnosis. Archival tissue from 64 patients with uterine smooth muscle neoplasms (20 leiomyomas (LMs), 22 atypical leiomyomas (ALMs), and 22 leiomyosarcomas (LMSs)) was immunostained with antibodies against estrogen (ER) and progesterone receptors (PR), COX-2 and c-kit. 7 of 20 LM cases and 5 of 22 ALM cases were immunopositive for COX-2, whereas none of the LMS cases stained immunopositive (p< or =0.05). 4 of 20 LM cases and 5 of 22 ALM cases were immunopositive for c-kit, whereas 15 of 22 LMS cases showed c-kit immunopositivity (p< or =0.05). In conclusion, very few LMs and ALMs show COX-2 immunopositivity. LMSs usually do not express COX-2. COX-2 expression in smooth muscle tumors is not a prominent feature. Therefore, COX-2 inhibitors may not be useful in LMS therapy. C-kit was significantly expressed in uterine LMSs.

Epstein-Barr virus-associated smooth muscle tumour mimicking bilateral vocal process granuloma

A case is presented of a 36-year-old Chinese woman with a renal transplant for end-stage renal failure due to Goodpasture's syndrome. She presented with a year's history of throat discomfort and acid regurgitation into her throat. Videolaryngoscopy revealed bilateral vocal process granuloma, presumed to be due to gastroesophageal reflux. A four-week course of high dose omeprazole was prescribed. On follow up a month later, the granulomas had enlarged, and laser excision was undertaken. Histological and immunohistochemical staining was consistent with Epstein-Barr virus-associated smooth muscle tumour. This is believed to be the first reported case in the English literature of such a tumour affecting the vocal process. The aim of this paper is to present the pathogenesis, clinical behaviour and treatment of Epstein-Barr virus-associated smooth muscle tumour, and to review the literature concerning the differential diagnosis of polypoid vocal process lesions.

Primary duodenal neoplasms: A retrospective clinico-pathological analysis

AIM: To analyze the clinico-pathological spectrum of primary duodenal neoplasms.

METHODS: A total of 55 primary duodenal neoplasms reported in the last 10 years after excluding ampullary and periampullary tumors were included in the study. Clinical details were noted and routine hematoxylin and eosin stained paraffin sections were studied for histological subtyping of the tumors.

RESULTS: On histopathological examination primary duodenal neoplasms were categorized as: epithelial tumor in 27 cases (49.0%) including 10 cases of adenoma, 15 cases of adenocarcinoma, and 2 cases of Brunner gland adenoma; mesenchymal tumor in 9 cases (16.3%) consisting of 4 cases of gastrointestinal stromal tumor, 4 cases of smooth muscle tumor and I case of neurofibroma; lymphoproliferative tumor in 12 cases (21.8%), and neuroendocrine tumor in 7 cases (12.7%).

CONCLUSION: Although non-ampullary/periampullary duodenal adenocarcinomas are rare, they constitute the largest group. Histopathological examination of primary duodenal tumors is important for correct histological subtyping.

Cotyledonoid leiomyoma in pregnancy

BACKGROUND

Benign smooth-muscle tumors (leiomyomata) are the most frequent tumors found in the female genital tract. They are easy to diagnose in pregnancy and usually managed conservatively. Some variant forms with unusual infiltrative growth pattern have been known, but they are rare in pregnancy. The variant forms pose diagnostic and management difficulties.

CASE

An unusual type of leiomyoma (cotyledonoid), adhering to the bowels and occupying the whole left broad ligament, was excised completely at 14 weeks of gestation, and the pregnancy continued to term.

CONCLUSION

Familiarity with benign uterine smooth-muscle tumors with unusual growth patterns by gynecologists and pathologists is essential in avoiding over-treatment.

Uterine smooth-muscle tumors with unusual growth patterns: imaging with pathologic correlation

OBJECTIVE

This essay illustrates the salient features of variant smooth-muscle tumors on multiple imaging techniques with correlative pathology. We describe how recognition of these features allows the radiologist to distinguish a uterine leiomyoma variant from the classic fibroid or a leiomyosarcoma. Finally, we highlight the role of the radiologist in triaging these patients to surgical versus medical management and in surgical planning.

CONCLUSION

Parasitic leiomyoma, intravenous leiomyomatosis, disseminated peritoneal leiomyomatosis, and benign metastasizing leiomyoma show key features on multiple imaging techniques that correlate with pathology findings. In the appropriate clinical setting, the radiologist should include these unusual lesions in the broader differential diagnosis of smooth-muscle tumors and, in certain cases, aid in surgical planning.

Single-Stage Resection of a Mixed Endometrial Stromal Sarcoma and Smooth Muscle Tumor With Intracardiac and Pulmonary Extension

A case of mixed endometrial stromal sarcoma and smooth muscle cell tumor of the uterus with intravenous extension into the right heart and pulmonary artery is presented. The current literature and diagnostic and therapeutic strategies of pelvic tumors with intravenous extension are reviewed.

A new scoring system using multiple immunohistochemical markers for diagnosis of uterine smooth muscle tumors

The diagnosis of uterine smooth muscle neoplasms by light microscopy is difficult. Multiple classification schemes have been proposed based on mitotic rate, nuclear atypia, and the presence or absence of necrosis. None of these classification systems has been entirely successful. This study was undertaken to evaluate the use of selected immunohistochemical and histochemical markers in differentiating these tumors, in addition to accepted morphologic criteria. Ten cases of each of the following: leiomyosarcomas (LMS), atypical leiomyomas (AL), cellular leiomyomas (CL) and usual leiomyomas (UL), were classically evaluated for histological diagnosis and were stained for Ki-67 (MIB-1), bcl-2 and p53 using monoclonal antibodies and the avidin-biotin peroxidase method, and argyrophilic nucleolar organizer region (AgNORs). The number of stained cells was counted in the most positively stained region in a 4 mm² square cover glass mounted on each slide. The mean value was calculated for each group of tumors. The data for Ki-67 (MIB-1), bcl-2, p53 and AgNOR staining respectively, were significantly higher in LMS by comparison to UL, CL or AL. Because many singular cases had superimposed data being difficult to diagnose, a new scoring system for pathological evaluation was created. The results obtained by this scoring system suggest that immunohistochemical markers Ki-67 (MIB-1), bcl-2, p53 together with the AgNOR staining could be useful, by the scoring system, as an adjunct to the current accepted morphologic criteria in differentiating smooth muscle tumors of the uterus.

Cotyledonoid Dissecting Leiomyoma of the Uterus

Cotyledonoid dissecting leiomyoma (Sternberg tumor) is a very rare variant of uterine smooth muscle tumor with an unusual and alarming gross appearance. Including our case, approximately 20 cases were reported in the literature. A 27-year-old woman presented with pelvic mass. A 41-cm fungating rubbery mass with placenta-like appearance adhering to the posterior uterine surface and extending to the left broad ligament and pelvic cavity was observed. An intraoperative frozen section was requested, and a diagnosis of a benign smooth muscle tumor was given. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed with removal of the pelvic tumor extension. Thorough tumor sampling was performed and showed nodules of interlacing bundles of bland-looking smooth muscle cells, separated by expanded, edematous, and highly vascularized stroma. No atypia, mitotic activity, or coagulative necrosis was seen. Immunohistochemical studies confirmed the smooth muscle nature of the tumor. Cotyledonoid leiomyoma has a distinctive gross appearance which usually raises the suspicion of sarcoma. Intraoperative frozen section is a mandatory and helpful procedure to avoid overtreatment of such cases.

Differential expression of smooth muscle myosin, smooth muscle actin, h-caldesmon, and calponin in the diagnosis of myofibroblastic and smooth muscle lesions of skin and soft tissue

The diagnosis of low-grade and pseudosarcomatous spindle cell lesions of skin and soft tissue can sometimes be problematic; in particular, distinction between fibroblastic, myofibroblastic, and smooth muscle proliferations can occasionally pose difficulties on routine histologic examination. We have applied a panel of immunohistochemical markers to a series of spindle cell lesions of skin and soft tissue to assess the utility of the differential expression of smooth muscle and myofibroblastic-associated markers. Twenty-eight cases of nodular fasciitis, 42 cases of fibromatosis, and 3 cases of myofibroblastic sarcoma were stained with antibodies against smooth muscle actin (SMA), smooth muscle myosin (SMMS), calponin, and high-molecular weight caldesmon (h-caldesmon). For comparison, 12 cases of cutaneous leiomyoma and 8 cases of leiomyosarcomas involving superficial soft tissues and fascia were studied with the same panel of antibodies. Thirty-eight of 42 cases of fibromatosis were positive for SMA, 42/42 cases were positive for calponin, 39/42 cases were negative for SMMS, and all cases were negative for h-caldesmon. All cases of nodular fasciitis were positive for SMA and calponin, and all were negative for h-caldesmon and SMMS. All cases of myofibroblastic sarcoma were positive for SMA and 2/3 cases for calponin, and were negative for SMMS and h-caldesmon. All cases of cutaneous leiomyoma and leiomyosarcoma were positive for all 4 markers tested. Our results demonstrate a remarkably consistent pattern of reactivity of muscle and myofibroblastic-associated markers in lesions predominantly composed of myofibroblastic spindle cells, characterized by positive staining for SMA and calponin and absence of reactivity for SMMS and h-caldesmon. Application of this panel of stains may be of aid in the differential diagnosis of low-grade myofibroblastic lesions such as nodular fasciitis and fibromatosis from smooth muscle tumors of skin and soft tissue. This panel may additionally be of assistance in the diagnosis of myofibroblastic sarcoma.

Smooth muscle tumour of the pharynx: a rare tumour presenting with globus pharyngeus symptoms

A rare case of a smooth muscle tumour in the pharynx is reported, together with histopathological findings. The patient’s psychiatric background and recurrent complaint of a sensation of a lump in the throat all pointed to a psychogenic aetiology, and diagnosis was delayed. The importance of mirror or endoscopic examination of the pharynx is stressed in patients with globus pharyngeus symptoms.

Analysis of Allelic Loss as an Adjuvant Tool in Evaluation of Malignancy in Uterine Smooth Muscle Tumors

Uterine smooth muscle tumors of uncertain malignant potential (STUMPs) are difficult both from the diagnostic and patient management standpoint because they cannot be classified as benign or malignant by conventional histologic criteria. This study's aim was to determine the diagnostic utility of allelic imbalance (AI) analysis in uterine smooth muscle tumors. Using microdissection and genotyping, we tested 5 leiomyomas, 6 STUMPs, and 10 leiomyosarcomas with follow-up for AI across a panel of seven tumor suppressor genes (p16, p21, p53, VHL, XRCC3, RB, and NM-23). None of the 6 patients with STUMP experienced recurrent disease, whereas 8 of the 10 patients diagnosed with leiomyosarcoma died of disease at follow-up. The mean frequency of allelic loss (FAL) for leiomyomas (18%) was not significantly different from that of STUMPs (21%) (P = 1), whereas leiomyosarcomas displayed a significantly higher FAL (52%) than both leiomyomas (P = 0.001) and STUMPs (P = 0.002). Loss of NM-23, a reported tumor metastasis suppressor gene, was found only in leiomyosarcomas (5 of 9, or 56%), and 4 of 5 (80%) of these were the only cases that demonstrated distant metastases (P = 0.04). Additionally, an FAL of >50% correlated with both NM-23 loss (P = 0.008) and distant metastatic disease (P = 0.04). In conclusion, leiomyomas and STUMPs displayed similar mean FALs and all were clinically benign, whereas uterine leiomyosarcomas had significantly higher frequencies of allelic loss than both leiomyomas and STUMPs. Molecular profiling may thus provide a valuable tool in assessment of malignancy in uterine smooth muscle tumors. Additionally, NM-23 is a promising candidate gene for determination of metastatic potential in these tumors.