Myoepithelioma-like tumor of the vulvar region: a case report in China and review of the literature

Update on Mesenchymal Lesions of the Lower Female Genital Tract

This article provides an update of the recent developments in mesenchymal tumors of lower genital tract. We focus on the characterization of recurrent molecular events in certain genital stromal tumors, for instance angiomyofibroblastomas and superficial myofibroblastomas. Moreover, fusions involving Tyrosine-kinases receptors (NTRK, FRFR1, RET, COL1A1-PDGFB) have been demonstrated in an emerging group of mesenchymal tumors characterized by a fibrosarcoma-like morphology and a predilection for uterine cervix of premenopausal women. We also cover the topic of smooth muscle tumors of the lower genital tract, which can be now classified using the same diagnostic criteria than their uterine counterpart..

Myoepithelioma-like tumors of the vulvar region: A case report and review of the literature

Myoepithelioma-like tumors of the vulvar region (MELTVR) is a kind of solid tumor newly recognized in recent years, which is characterized by mesenchymal tumors of adult female vulva. The histopathology is similar to myoepithelioma, but the immunohistochemical phenotype and genetic changes are different from myoepithelioma. It usually has clear boundary and partial capsule, mixed with two forms of cells (epithelioid and spindle), the cells are mild, the nucleoli are clear, mitoses are rare, some cases have myxoid differentiation. In this article, a case of MELTVR diagnosed in our hospital is discussed. The patient was a 43-year-old female who finds a neoplasm in the pubic tubercle 4 months ago. Local resection was performed. Pathological examination showed that the boundary of the tumor was clear with partial capsule. The cells were arranged in cords or nests, and partially infiltrated the surrounding adipocytes. The tumor cells had two morphologies, epithelioid or spindle shaped. The spindle type cells were dominant, with bright cytoplasm, obvious nucleoli, rare nuclear mitosis (about 1/10HPF), and no necrosis was observed. Immunohistochemically, the tumor cells were positive for vimentin, epithelial membrane antigen, estrogen receptor, progestogen receptor, calponin and were partially positive for cathepsin k. INI1/SMARCB1 expression was deficient. There was no recurrence or metastasis during the 8-month-long follow-up. The unique feature of this case was that the site of the disease was not the vulva, but in front of the pubic tubercle, there was no large amount of mucus production, and the cytoplasm of most tumor cells was transparent. Due to our limited knowledge of MELTVR, its pathogenesis and tissue origin are not clear. Clinicians should be aware of such potential patients.

A case of retroperitoneal tumor displaying epithelial differentiation, prominent myxoid stroma and loss of INI1/SMARCB1

The clinicopathological spectrum of INI1 deficient tumors is expanding. Epithelioid sarcoma (ES) is a rare sarcoma of uncertain differentiation, more often occurring in the extremities and uncommonly in the deep soft tissues. Histopathologically, it manifests in the form of classical, proximal, or hybrid types, the latter two characterized by rhabdoid cytomorphology. Immunohistochemically, ESs display loss of INI1/SMARCB1 and genetically associated with high percentage of SMARCB1 deletions

We report an extremely uncommon case of a retroperitoneal tumor in a 42-year-old male, who presented with abdominal discomfort. Radiologic imaging disclosed a 12 cm-sized retroperitoneal mass without involvement of any organ parenchyma. The patient underwent tumor excision with left-sided nephrectomy at another hospital. A review of the paraffin-embedded tissue sections revealed a multinodular tumor, composed of dyscohesive epithelioid tumor cells and focally arranged in cords, containing moderate to abundant, eosinophilic cytoplasm, vesicular nuclei, containing prominent nucleoli, including cells with rhabdoid cytomorphology, in a conspicuous myxoid stroma. A focal tumor area resembled proximal-type of ES. Immunohistochemically, tumor cells displayed positivity for pan cytokeratin (AE1/AE3), epithelial membrane antigen (EMA), vimentin and focally for CA125, while these were negative for CD34, S100 protein, CKIT, DOG1, and INI1/SMARCB1.

To the best of our knowledge, this constitutes the first case of a malignant tumor with epithelioid morphology, displaying myxoid matrix and loss of INI1/SMARCB1, resembling a myxoid variant of an epithelioid sarcoma and myoepithelioma-like tumor of the vulvar tumor, occurring in the retroperitoneum. A review of similar cases, differential diagnosis and treatment-associated implications are presented.

Myoepithelioma-like tumour of the vulval region: A case report

Myoepithelioma-like tumours of the vulvar region (MELTVR) are a newly described group of spindle cell neoplasm. Morphologically, they consist of epithelioid to spindled cells in a myxoid to collagenous stroma and can resemble epithelioid sarcomas, myoepithelial carcinomas or extraskeletal myxoid chondrosarcomas. However, they have a distinct pattern of immunohistochemical staining characterised by positivity for EMA, ER, PR and negativity for cytokeratin, GFAP and S100. Nuclear staining for INI-1 is lost. In addition, they lack the characteristic gene arrangements of these other lesions. MELTVR can recur locally when incompletely excised, however, do not appear to metastasize. We report a case of a MELTVR in a 49-year-old woman arising in the right mons pubis.

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.