Myoepithelial neoplasms involving the vulva and vagina: report of 4 cases

Primary myoepithelial carcinoma of the Vulva: Case of a rare tumor with malignant potential and review of literature

•Primary myoepithelial carcinoma is rare with a handful of cases reported from the vulva.•There is no standard of treatment for primary myoepithelial carcinoma.•Current recommendations suggest excision with wide margins to be the best therapy.•Chemotherapy and immunotherapy should be considered in combination with excision.

Proximal-type epithelioid sarcoma of vulva – Case series of a rare tumor

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Proximal-type Epithelioid sarcoma of the vulva is a rare, aggressive soft tissue neoplasm seen in young and middle-aged females.

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Biopsy of the lesion with immunohistochemistry aids in diagnosis and differentiating from benign mimics.

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Loss of INI1 is characteristic and seen in the majority.

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Surgery is the mainstay of management in localized disease.

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Recently, Tazemetostat has obtained accelerated FDA approval for use in locally advanced and metastatic settings.

Epithelioid sarcoma (ES) is rare and aggressive soft tissue neoplasm characterized by tumor cells showing epithelioid morphology and immunohistochemically, characteristic loss of INI1/ SMARCB1 in most cases. The proximal-type ES usually involves the deeper soft tissues of the vulva or perineum is an extremely rare entity with diagnostic challenges. Surgery is the mainstay of treatment in localized diseases. Radiation and chemotherapy are used in the advanced and metastatic setting, however, their role in the adjuvant setting is uncertain. Anthracycline and gemcitabine-based chemotherapy are given in metastatic and recurrent tumors. We report 4 cases of ES treated over a period of 6 years at our center. All the cases initially presented at a local hospital with vulvar swelling with a benign mimic (3/4) or squamous cell carcinoma (1/4). The median age of diagnosis was 34 years (range 17–80). The diagnosis was established with epithelioid morphology of tumor cells and immunohistochemically characteristic loss of INI1/SMARCB1 in all cases. 3 cases were treated with upfront surgery and two of them received adjuvant radiotherapy. One case received upfront palliative therapy due to lung metastasis at the time of presentation. On median follow-up of 24 months (2–63), 2 cases were disease-free. One case had a recurrence in the lungs and chest wall after a disease-free interval of 63 months. She underwent surgical excision of metastatic deposits, however developed second lung recurrence after 3 months and is being treated with Adriamycin-based chemotherapy. All patients are alive at the last follow-up.

Update on SWI/SNF-related gynecologic mesenchymal neoplasms: SMARCA4-deficient uterine sarcoma and SMARCB1-deficient vulvar neoplasms

Our knowledge regarding the role of genes encoding the chromatin remodeling switch/sucrose non-fermenting (SWI/SNF) complex in the initiation and progression of gynecologic malignancies continues to evolve. This review focuses on gynecologic tumors in which the sole or primary genetic alteration is in SMARCA4 or SMARCB1, two members of the SWI/SNF chromatin remodeling complex. In this review, we present a brief overview of the classical example of such tumors, ovarian small cell carcinoma of hypercalcemic type, and then a detailed review and update of SMARCB1-deficient and SMARCA4-deficient tumors of the uterus and vulva.

SWI/SNF-deficient malignancies of the female genital tract

Mutations and other molecular events involving subunits of the SWI/SNF chromatin remodelling complex are common in a wide variety of malignancies, including those arising at various sites in the female genital tract. Endometrioid and clear cell carcinomas in the uterine corpus and ovary not uncommonly contain mutations in ARID1A and these also occur in other endometriosis-associated ovarian neoplasms such as seromucinous tumours. In these organs, mutations in SMARCA4, SMARCB1, ARID1A and ARID1B (with subsequent loss of corresponding protein expression as a reliable surrogate) are relatively common in undifferentiated carcinomas, including the undifferentiated component of dedifferentiated carcinoma. SMARCA4 mutations are extremely common (almost ubiquitous) in small cell carcinoma of the ovary of hypercalcaemic type (SCCOHT), occurring in about 98% of these neoplasms, often in association with epigenetic SMARCA2 loss. SMARCB1-deficient vulval neoplasms include epithelioid sarcoma and myoepithelial carcinoma, as well as related malignancies which defy easy classification. Recently the spectrum of SWI/SNF deficient female genital malignancies has been expanded to include SMARCA4-deficient undifferentiated uterine sarcoma and mural nodules of anaplastic carcinoma in ovarian mucinous neoplasms.

Vulval Microglandular Adenosis-like Neoplasm With Chondromyxoid Stroma: Report of a Unique Case

Microglandular adenosis of the breast is an uncommon lesion which can mimic tubular carcinoma. It is composed of small round tubules lined by a single layer of flat or cuboidal epithelial cells, often with eosinophilic colloid-like material within the lumen. The absence of a myoepithelial cell layer and preservation of basement membrane around the tubules are characteristic features. We report the first case of a vulval "neoplasm" in a 60-yr-old woman showing features identical to microglandular adenosis of the breast except for the presence of an unusual chondromyxoid stroma. This case reinforces the analogy between vulval lesions derived from anogenital mammary-like glands and breast lesions and also adds a new entity to the list of lesions arising from these glands.

Myoepithelioma-like Tumors of the Vulvar Region: A Distinctive Group of SMARCB1-deficient Neoplasms

We describe 9 tumors that resemble soft tissue myoepitheliomas but possess certain traits that do not fit perfectly into this category. These tumors, herein referred to as "myoepithelioma-like tumors of the vulvar region," occurred in the subcutis of the vulva and surrounding regions of adult women aged 24 to 65 years. Histologically, the tumors measured 2 to 7.7 cm and were well circumscribed, focally encapsulated, and lobulated. Tumor cells had an epithelioid to spindled shape, with fine amphophilic cytoplasm, and uniform nuclei with vesicular chromatin and nucleoli. The tumor stroma was relatively hypervascular, and comprised a mixture of myxoid and nonmyxoid components. Myxoid areas accounted for <5% to 95% of the tumor volume, wherein cells proliferated singly or in a loosely cohesive manner. In nonmyxoid areas, tumors cells grew in diffuse sheets or storiform arrangements. Immunohistochemically, all tested tumors were positive for vimentin, epithelial membrane antigen, and estrogen receptor; most tumors expressed actin. All tumors were negative for S100 protein, glial fibrillary acidic protein, and CD34. Cytokeratin expression was absent in all but 2 tumors, which showed rare positivity. SMARCB1 expression was deficient in all cases. EWSR1, FUS, and NR4A3 rearrangements were absent. All tumors were treated through surgery. Although 3 tumors regrew or recurred after intralesional excision, all 9 patients were alive without metastases at a mean follow-up of 66 months. Myoepithelioma-like tumors of the vulvar region constitute a distinct group of tumors, although future research is required to determine whether they are an unusual subtype of soft tissue myoepitheliomas or a separate disease.

Myoepithelioma of the ovary: first reported case

A wide variety of neoplasms of varying histogenesis occur within the ovary. We report the first case of a primary ovarian myoepithelioma, a diagnosis made on the basis of the morphologic features coupled with immunoreactivity with epithelial and myoid markers. The tumor had a lobulated appearance with variable architectural patterns including anastomosing cords, trabeculae, and nests of epithelioid to spindled tumor cells within a hyalinised and focally myxoid stroma. Fluorescence in situ hybridization for EWS gene rearrangement and reverse transcriptase polymerase chain reaction for EWSR1-POU5F1 and EWSR1-PBX1, molecular abnormalities which are found in some extrasalivary myoepitheliomas, were negative. In reporting this unique neoplasm, we discuss the wide differential diagnosis generated by the case.

Unusual myoid, perivascular, and postradiation lesions, with emphasis on atypical vascular lesion, postradiation cutaneous angiosarcoma, myoepithelial tumors, myopericytoma, and perivascular epithelioid cell tumor

In recent years, a number of new soft tissue tumor entities have been described that occur in the skin only, or that also occur in other sites but form clinically and pathologically distinct subsets when arising in the skin and subcutaneous tissue. These include a variety of mesenchymal lineages and have variable malignant potential, although superficial malignant soft tissue tumors generally have a more favorable outcome than their more deeply located counterparts. This article reviews the clinical and pathologic features and differential diagnoses of atypical vascular lesion, postradiation cutaneous angiosarcoma, myoepithelioma, myopericytoma, and perivascular epithelioid cell tumor.

Primary myoepithelial carcinoma of the vulva and review of the literature

Myoepithelial carcinoma of the vulva is extremely rare, with only five cases reported. Here, we describe a case of vulvar myoepithelial carcinoma along with a review of the literature. The patient, a 49-year-old woman, was referred for a tumor on the right labium majora. She underwent a wide local excision and bilateral inguinal lymph node dissection. Pathological examination revealed an unencapsulated, infiltrative pattern, with solid, nested and trabecular components and areas with myxoid or hyalinized stroma. The tumor consisted of oval to round epithelioid cells with moderate nuclear pleomorphism. By immunohistochemistry, the tumor cells were diffusely positive for cellular adhesion molecule (CAM) 5.2, epithelial membrane antigen (EMA), S-100 protein, and vimentin and focally positive for carcinoembryonic antigen (CEA) and p63, while negative for alpha- smooth muscle actin (SMA). The tumor was diagnosed as a myoepithelial carcinoma of the vulva, with metastases to the bilateral inguinal lymph nodes. Following completion of adjuvant radiotherapy, the patient remained alive without any evidence of recurrence at 56 months. A review of six cases of this tumor (including the present case), demonstrated variable morphology with some overlapping features. Therefore, immunohistochemistry using a panel of epithelial and myogenic markers is essential for definitive diagnosis. Two cases had inguinal lymph node metastases and received adjuvant radiotherapy or concurrent chemoradiotherapy, which resulted in good local control. One case had lung metastasis and was successfully treated by chemotherapy. Given the rarity of this disease and its uncertain prognosis, no clinical trials have been conducted regarding the necessity of adjuvant therapy. Myoepithelial carcinomas of the vulva are extremely rare making case series the most viable means of optimizing diagnosis and therapy.