Alveolar Soft Part Sarcoma of the Female Genital Tract: A Morphologic, Immunohistochemical, and Molecular Cytogenetic Study of 10 Cases With Emphasis on its Distinction From Morphologic Mimics

The Spectrum of Fusions Occurring in Non-Smooth Muscle Mesenchymal Uterine Tumors: A Review of the Current Knowledge

CONTEXT.—

Non-smooth muscle uterine sarcomas are mostly represented by low-grade endometrial stromal sarcoma. However, several other rare, distinct types of uterine sarcoma are recognized, including high-grade endometrial stromal sarcoma, tumors with kinase fusions, uterine tumors resembling ovarian sex cord tumors, soft tissue-type sarcoma, and emerging entities such as KAT6A/B-rearranged tumors. The landscape of uterine sarcomas has changed, mostly because of the increasing knowledge concerning their molecular aberrations.

OBJECTIVE.—

To offer a comprehensive review of the literature focusing on fusions occurring in tumors other than smooth muscle mesenchymal uterine tumors with respect to their type, frequency, and overlap between diagnostic categories and entities.

DATA SOURCES.—

The data were mined from the PubMed/MEDLINE database covering the time period from January 1988 to June 2023. In total, 156 studies focusing on the problematics of fusions occurring in non-smooth muscle mesenchymal uterine tumors were selected, and thus became the basis for this review.

CONCLUSIONS.—

One hundred ten fusions were identified in 703 tumors. The diagnostic significance of the molecular aberrations occurring in these tumors can be unclear in some cases. This can be related to the rare aberrations with a limited number of reported cases. Additionally, even well-known aberrations considered as specific for a certain distinct entity can occur in other lesions, the biological behavior and clinical significance of which can differ substantially.

[Translocation-associated uterine mesenchymal tumors: The new without forgetting the old. An integrated diagnostic approach]

This review focuses on uterine mesenchymal tumors that are defined on a molecular level by a single and unique genetic alteration, that is somehow necessary and sufficient to allow tumor growth and progression. Although diverse from a clinical, morphological and immunohistochemical point of view, the different entities we are going to talk about share both a simple genomic profile with a low number of chromosomal alterations observed by CGH Array (few deletions, gains or amplifications...) and a low mutational burden observed by sequencing technics. Some of these entities are already well known and described in the literature when found outside of the uterus and gynecological tract. It remains intriguing that uterine mesenchymal pathology has been lagging behind when compared to its extrauterine counterpart. How can we explain that when it comes to inflammatory myofibroblastic tumors, abundant numbers of articles have been published since the 70's, but it was only in the early 2000s that the first relevant descriptions of this tumor in the uterus emerged? Certainly, the increased accuracy, availability, and use of molecular biology technics and in particular RNA sequencing in the area of uterine pathology can partly explain the reduction of the gap between soft tissue and uterine pathology we currently observe. Other reasons explaining this gap may be the high prevalence of smooth muscle tumors in the uterus and the abounding diversity of their morphological aspects, which may have partly eclipsed the array of differential diagnoses. Last but not least, one can hypothesize that the relative "simplicity" of hysterectomy procedures, referring to their safety and accessibility, has cured most of the lesions and partly clouded our knowledge regarding the biological potential and natural history of these newly described entities. As a consequence of this situation, our reader will often encounter the wording "uncertain malignant potential", as for some of these rare entities, evidence to establish reliable prognostic variables is still insufficient. We hope this review to be a useful tool to guide pathologists through the diversity and complexity of uterine mesenchymal tumors. As a scientific and medical community, sharing this knowledge will help us to collectively raise our vigilance and awareness by expanding the array of our differential diagnoses. We hope this will lead to more cases being accurately diagnosed, and ultimately, to a deeper knowledge regarding the biological potential and clinical evolution of these tumors. From a therapeutical point of view, the consequences of an accurate diagnosis for the patient are already appreciable through the use of targeted therapy. Examples include: ALK inhibitors in inflammatory myofibroblastic tumor, tyrosine-kinase inhibitors in COL1A::PDGFB rearranged sarcomas or mTOR inhibitors in PEComa.

Primary Uterine Alveolar Soft Part Sarcoma in a Postmenopausal Woman: Histopathologic and Immunohistochemical Characteristics of a Rare Case

BACKGROUND

Primary uterine alveolar soft part sarcoma (ASPS) is a rare, indolent mesenchymal malignancy with less than 40 patients documented in the literature.

CASE

We report an example of ASPS in a 61-year-old postmenopausal woman. Macroscopically, the uterus showed multiple nodular masses. Microscopic examination revealed tumor arranged in nests and alveolar pattern. The tumor cells were moderately to markedly pleomorphic, epithelioid to polygonal, with eccentrically placed nuclei, vesicular chromatin, prominent macro-nucleoli, and moderate to abundant eosinophilic cytoplasm. PAS-positive and diastase-resistant intracytoplasmic crystals were also seen in some tumor cells. On immunohistochemistry, the tumor cells showed diffuse positivity for vimentin and nuclear positivity for TFE3, a surrogate marker for ASPS. These were negative for SMA, desmin, CD10, h-caldesmon, cyclin D1, EMA, Melan A, and CD34. SMARCB1 expression was retained. Based on the histopathology and IHC, a final diagnosis of uterine ASPS was rendered.

CONCLUSIONS

Knowledge of the characteristic histopathologic and immunohistochemical features can help accurately diagnose such rare tumors. Knowledge of the characteristic histopathologic and immunohistochemical features can help accurately diagnose such rare sarcoma in an uncommon site with an unusual age.

Systematic analysis of perivascular epithelioid cell neoplasms in the female reproductive tract: a comprehensive review

Perivascular epithelioid cell neoplasms (PEComas) are rare mesenchymal lesions, with gynecological PEComas accounting for just over a quarter of cases. Limited reports exist on gynecological PEComa, primarily treated with surgery; adjuvant therapy is considered in high-risk cases. This systematic review aims to summarize the origin and clinical, pathological and molecular characteristics of uterine PEComa, focusing on treatment options for gynecological PEComa. A comprehensive PubMed review of gynecological PEComa reports was conducted. A detailed examination of the literature ensured a thorough understanding. Gynecological PEComa diagnosis relies on histology and immunology. Despite therapy controversies, surgery remains the mainstay. Adjuvant therapy efficacy in high-risk cases is uncertain. mTOR inhibitors are the first line; alternative treatments, including angiogenesis and aromatase inhibitors, should be considered.

Alveolar Soft Part Sarcoma in the Female Genital Tract: Case Series with Literature Review and SEER Database Analysis

Introduction

Alveolar soft part sarcoma (ASPS) is a rare and distinct subtype of soft tissue sarcoma. This study aims to describe the unique presentation of ASPS in the female genital tract.

Methods

Prognostic factors for cancer-specific overall survival (CSS) were evaluated using multivariate analyses.

Results

In our case series, we identified a novel TFE3-PRCC gene fusion in a 24-year-old unmarried patient with cervical ASPS who underwent fertility-sparing surgery and remained recurrence-free for 41 months. The other two patients underwent radical hysterectomy and bilateral salpingo-oophorectomy. At the time of writing, the two patients had been disease-free for 49 and 71 months, fluorescence in situ hybridization showed break-apart signals for the ASPL-TFE3 gene. Among the 55 cases with available information from the PubMed/Medline database, most presented with localized disease, and at the last follow-up, all patients were alive and 45 patients showed no evidence of disease. The 5-year CSS rate in the female genital tract cohort from SEER database was 86.2%. Multivariate analysis revealed that older age was associated with a 1.042-fold increased risk of cancer-specific mortality (HR=1.042, 95% CI 1.022-1.063, P < 0.001), involvement of soft tissue including the heart was associated with a 4.786-fold higher risk (HR=4.7868, 95% CI 1.681-13.623, P= 0.003), and regional infiltration and distant metastasis were associated with approximately 8.6-fold and 18-fold higher risk of cancer-specific mortality compared to local disease, respectively (HR=8.652, 95% CI 2.529-29.63, P = 0.001; HR=18.366, 95% CI 6.153-54.817, P< 0.001). Patients who underwent radical excision did not show reduced cancer-specific mortality compared to those who underwent local excision (HR=0.492, 95% CI 0.224-1.081, P = 0.078).

Discussion

Previously unrecognized genetic diversity exists in ASPS. Patients with ASPS in the female genital tract have the lowest likelihood of presenting with a distant disease and are associated with a more favorable survival outcome.

Alveolar soft part sarcoma of the uterine corpus: A 13-year follow-up case report and review of the literature

OBJECTIVE

Female genital alveolar soft part sarcoma (ASPS) is rare and has a favourable prognosis compared to ASPS from other sites. We reported our experience to manage a case with uterine corpus ASPS (UC ASPS) and conducted a literature review on prognosis of ASPS from different sites of female genital tract.

CASE REPORT

This report represented a 33-year-old woman who had UC ASPS. She received tumor excision with uterine preservation and had the longest follow-up time (155 months) without recurrence in the literature.

CONCLUSION

UC ASPS has better prognosis than ASPS from the uterine cervix, the low uterine segment, vulvovaginal area and perineum. We recommended conservative treatment for young women with UC ASPS.

Data Set for Reporting of Uterine Malignant and Potentially Malignant Mesenchymal Tumors: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

The International Collaboration on Cancer Reporting (ICCR) seeks to produce standardized, evidence-based protocols for the reporting of tumors with the aim of ensuring that all cancer reports generated worldwide will be of similar high quality and record the same elements. Herein, we describe the development of the data set for the reporting of uterine malignant and potentially malignant mesenchymal tumors by a panel of expert pathologists and a single clinician and provide the commentary and rationale for the inclusion of core and noncore elements. This data set, which incorporates the recent updates from the 5th edition of the World Health Organization Classification of Female Genital Tumors, addresses several subjects of debate including which mesenchymal tumors should be graded, how to document extent of invasion, mitotic counts, and the role of ancillary testing in tumor diagnosis and patient management. The inclusion of elements is evidence-based or based on consensus of the expert panel with clinical relevance being the guiding standard.

Alveolar Soft Part Sarcoma of the Uterus: Clinicopathological and Molecular Characteristics

Alveolar soft part sarcoma (ASPS) is a rare malignant mesenchymal tumor mainly affecting adolescents and young adults, with a predilection for the deep soft tissues of extremities. ASPS arising in the female genital tract is extremely rare and poses a significant diagnostic challenge. We herein present two rare cases of ASPS, one occurring in the uterine corpus of a 27-year-old woman, and the other in the uterine cervix of a 10-year-old girl. We described the clinical, histological, immunophenotypical, and molecular characteristics of primary uterine ASPS. We performed immunostaining for transcription factor E3 (TFE3), human melanoma black 45 (HMB45), melan-A, desmin, pan-cytokeratin (CK), paired box 8 (PAX8), CD10, hormone receptors, and S100, and targeted RNA and DNA sequencing using commercially available cancer gene panel. In case 1, a 27-year-old woman was referred to our hospital after laparoscopic uterine myomectomy at an outside hospital. Imaging studies revealed a residual tumor in the uterine corpus. In case 2, a 10-year-old girl underwent surgical excision for the cervical mass and was diagnosed as having ASPS. She was then referred to our hospital for further management. Both patients received total hysterectomy. Histologically, they displayed characteristic histological features of ASPS. Strong nuclear TFE3 immunoreactivity, periodic acid-Schiff-positive, diastase-resistant intracytoplasmic rod-shaped crystalloids or granules, and the identification of ASPSCR1–TFE3 fusion confirmed the diagnosis of ASPS in both cases. Lack of immunoreactivity for HMB45, melan-A, desmin, pan-CK, PAX8, and S100 excluded the possibility of perivascular epithelioid cell tumor, clear cell sarcoma, metastatic renal cell carcinoma, granular cell tumor, and paraganglioma. Our observations can help pathologists make an accurate diagnosis of uterine ASPS and suggest that pathologists should include primary uterine ASPS in the differential diagnosis of uterine mesenchymal tumors.

Paraganglioma of the Vagina Associated With Germline SDHB Mutation: Report of a Case With Review of the Literature

Paragangliomas are rare neuroendocrine neoplasms in the vagina, and their molecular pathogenesis has not been documented. We report a case of vaginal paraganglioma in a 15-yr-old adolescent girl who presented with irregular heavy menses and anemic symptoms. Examination under anesthesia revealed a polypoid mass of 3 cm size in the left anterior vaginal wall, which was resected piecemeal. Histology showed a circumscribed nodular tumor with typical nested morphology of paraganglioma and no significant nuclear atypia. Immunohistochemically the tumor cells were diffusely positive for synaptophysin and chromogranin while being negative for cytokeratin, accompanied by S100-positive sustentacular cells. SDHB immunohistochemistry demonstrated the absence of cytoplasmic staining in the tumor cells with preserved staining in sustentacular cells, raising the possibility of a germline mutation in the genes encoding subunits of succinate dehydrogenase. Sanger sequencing for all the exons and exon-flanking intronic regions of the SDHB gene revealed no mutation, but further investigation with multiplex ligation-dependent probe amplification identified a heterozygous deletion of exon 1 of the SDHB gene in the patient and her mother, confirming the diagnosis of SDHB-related hereditary paraganglioma-pheochromocytoma syndrome. The patient had no evidence of disease upon imaging surveillance and follow-up for 56 mo. A review of the published cases of vaginal paraganglioma seems to suggest a relatively young age of presentation, commonly encountered as incidental findings in asymptomatic patients or presenting with abnormal vaginal bleeding. The association between vaginal paraganglioma and germline SDHB mutation has not been reported. We believe this case illustrates the clinical significance of SDHB immunohistochemistry and genetic testing for this rare vaginal neoplasm.

Alveolar Soft Part Sarcoma of Uterine Corpus in a Young Female: A Case Report With Review of Literature

Alveolar soft part sarcoma (ASPS) is a rare soft tissue sarcoma, often occurs in adolescents and young adults with a particular predilection for the deep soft tissue of extremities. Occurrence of ASPS in the female genital tract is very uncommon and poses a significant diagnostic challenge. A case of ASPS of the uterine corpus is described in a young unmarried female, who presented to the out-patient clinic of our Institute with complaints of abnormal uterine bleeding for the past 9 mo. She was being treated with oral contraceptive pills, progesterone and tranexamic acid. Following radiological imaging and hysteroscopy, a therapeutic curettage of the lesion was done. The histopathologic features raised a differential diagnosis of a myriad of morphologic mimickers. The diagnosis was clinched by exclusion of mimickers by relevant immunohistochemical markers and strong nuclear expression of TFE3 on immunohistochemistry. The patient is on regular follow-up with oral contraceptives and antifibrinolytic medication. Despite being infrequent at this location, ASPS should be kept in differential diagnosis in young females presenting with abnormal uterine bleeding.

Perivascular epithelioid cell tumors (PEComa) of the gynecologic tract

PEComas of the female genital tract are rare mesenchymal neoplasms that are most common in the uterus, but also may occur in other gynecologic locations. As they morphologically and immunohistochemically resemble smooth muscle tumors, distinction between the two entities is often challenging, and may be aided by molecular analysis. Thus far, two distinct molecular groups-classic PEComas with TSC mutations and TFE3-translocation associated PEComas with TFE3 fusions have been described. Recognition of the first group is imperative as these patients may benefit from targeted therapy with mTOR inhibitors, if malignant. This review will focus on recognition of the morphologic and immunophenotypic features of PEComas, as well as the role of molecular testing in their diagnosis and treatment, analysis of the different algorithms to predict behavior, and differential diagnosis.

Mesenchymal lesions of the vulva

Mesenchymal lesions of the vulva include site-specific entities limited to the lower genital tract, as well as a range of non-site-specific tumors that are more common at extragenital sites. Site-specific lesions include fibroepithelial stromal polyp, cellular angiofibroma, angiomyofibroblastoma, and aggressive angiomyxoma. Non-site-specific tumors that may occur in the vulva include those of smooth muscle, skeletal muscle, vascular, neural, adipocytic, and uncertain differentiation. This review discusses both site-specific and non-site-specific vulvar mesenchymal lesions including non-neoplastic proliferations, benign neoplasms, locally aggressive neoplasms with a predilection for local recurrence, neoplasms of indeterminate biologic potential, and frankly malignant neoplasms with a high risk of distant metastasis and death. Accurate diagnosis is essential for proper management, and is facilitated by correlation with clinical findings and targeted application of immunohistochemical and molecular studies.

A Comprehensive Review of Biomarker Use in the Gynecologic Tract Including Differential Diagnoses and Diagnostic Pitfalls

Morphologic (ie, hematoxylin and eosin) evaluation of the Mullerian tract remains the gold standard for diagnostic evaluation; nevertheless, ancillary/biomarker studies are increasingly utilized in daily practice to assist in the subclassification of gynecologic lesions and tumors. The most frequently utilized "biomarker" technique is immunohistochemistry; however, in situ hybridization (chromogenic and fluorescence), chromosomal evaluation, and molecular analysis can also be utilized to aid in diagnosis. This review focuses on the use of immunohistochemistry in the Mullerian tract, and discusses common antibody panels, sensitivity and specificity of specific antibodies, and points out potential diagnostic pitfalls when using such antibodies.

Alveolar soft part sarcoma presenting as a uterine polyp: A case report

Alveolar soft part sarcoma is a rare malignant soft tissue tumor, mainly localized in the extremities and occurring principally in adolescents and young adults. Alveolar soft part sarcoma are uncommon in the female genital tract. We here report a case of alveolar soft part sarcoma in a 20-year-old nullipara, presenting with vaginal bleeding and profound anemia requiring blood transfusions. Ultrasonographic examination revealed a polyp in the lower uterine segment. Surgical resection of the polyp was performed, and pathological evaluation showed typical histological, immunohistochemical, and molecular features consistent with alveolar soft part sarcoma. Patient underwent for total hysterectomy. Currently, she follows up with her surgeon and has no new complains. Given the infrequency of alveolar soft part sarcoma, this case report raises the awareness of alveolar soft part sarcoma as one of the entities to consider when confronted with a uterine polyp in a young patient.

Alveolar soft part sarcoma metastatic to the breast: a case report

Background

Alveolar soft part sarcoma (ASPS) is an extremely rare neoplasm that tends to occur in the lower limbs of children and adolescents. Metastatic breast tumors constitute 0.5–2.0% of all malignant mammary neoplasms, and cases of ASPS with mammary metastases are very rare.

Case presentation

Three years ago, an 11-year-old girl presented to the hospital with pain in the right jaw after becoming aware of a mass in the right cheek. After detailed examination, the patient was diagnosed with ASPS with the primary tumor in the right cheek and multiple lung metastases, and chemotherapeutic treatment was initiated. One year later, accumulation of fluorodeoxyglucose (FDG) was observed in the right front of the skull (standardized uptake value (SUV)-max 2.8) and left breast (SUV-max 2.4) using FDG-positron emission tomography (PET) / computed tomography (CT). Ultrasonography revealed the mammary tumor as a hypoechoic, internally heterogeneous mass measuring 22.4 × 16.2 × 21.1 mm with a rich blood supply. Using pathological findings of core-needle biopsy, we diagnosed it as ASPS. Based on the above information, we made a diagnosis of ASPS with left mammary and cranial metastases. Due to chemoresistance, surgical excision was selected as the mode of treatment; resection of the metastatic cranial bone was performed first, and partial mastectomy of the left breast was performed in two stages. Postoperative conditions were good, and we are currently performing regular follow-ups (visual palpation every 3 months and semi-annual mammary gland ultrasonography).

Conclusions

We have reported an extremely rare case of ASPS with mammary metastasis with some reference-based discussion. In our case, disease control was obtained by a combination of drug therapy and surgical treatment.