Proximal-type Epithelioid Sarcoma of the Vulva: Relationship to Malignant Extrarenal Rhabdoid Tumor

Proximal-type epithelioid sarcoma of the perineum: A case report and literature review

Proximal-type epithelioid sarcoma of the perineum is a rare soft-tissue malignancy, and only 55 cases have been reported in the English literature to date. This tumor has an indetectable early symptom and frequent recurrences. Here, we present the case of a 31-year-old man with proximal-type epithelioid sarcoma of the perineum who underwent wide excision. Further, we reviewed the current literature regarding differential diagnosis and management of this disease.

Vulvar Yolk Sac Tumors Are Somatically Derived SMARCB1 (INI-1)-Deficient Neoplasms

So-called primary yolk sac tumors of the vulva are very rare and often have an aggressive disease course. Their molecular features have not been previously characterized. There is also a well-documented group of SMARCB1 (INI-1)-deficient vulvar neoplasms, which includes proximal-type epithelioid sarcoma and myoepithelial carcinoma. Until now, "vulvar yolk sac tumors" and SMARCB1-deficient neoplasms were considered unrelated diseases. After reviewing an index case of a vulvar yolk sac tumor with loss of SMARCB1 by immunohistochemistry, we retrospectively identified 2 additional cases diagnosed as vulvar yolk sac tumors. Patient ages were 34, 32, and 25 years old, and 2 tumors were associated with a pregnancy. All 3 cases showed morphology typical of a yolk sac tumor, and by immunohistochemistry all were positive for SALL4, glypican-3, keratins, and lacked CD34 positivity. All tumors also demonstrated loss of SMARCB1 in tumor cells. Targeted molecular profiling was performed in 2 cases and identified 2 copy deletion of SMARCB1, without genomic alterations typically seen in gonadal yolk sac tumors. In the third case, isochromosome 12p was not identified by fluorescence in situ hybridization. All 3 patients had either local recurrences or distant metastases, and 2 died of disease. One patient had progressive disease while receiving the enhancer of zeste homolog 2 inhibitor tazemetostat. Overall, these findings suggest that vulvar tumors with pure yolk sac-like morphology may represent morphologic variants of SMARCB1-deficient tumors and not veritable germ cell neoplasia. This potential reclassification may have both prognostic and treatment implications and warrants study of additional extragonadal yolk sac tumors.

SMARCB1/INI1-deficient tumors of adulthood

The SMARCB1/INI1 gene was first discovered in the mid-1990s, and since then it has been revealed that loss of function mutations in this gene result in aggressive rhabdoid tumors. Recently, the term "rhabdoid tumor" has become synonymous with decreased SMARCB1/INI1 expression. When genetic aberrations in the SMARCB1/INI1 gene occur, the result can cause complete loss of expression, decreased expression, and mosaic expression. Although SMARCB1/INI1-deficient tumors are predominantly sarcomas, this is a diverse group of tumors with mixed phenotypes, which can often make the diagnosis challenging. Prognosis for these aggressive tumors is often poor. Moreover, refractory and relapsing progressive disease is common. As a result, accurate and timely diagnosis is imperative. Despite the SMARCB1/INI1 gene itself and its implications in tumorigenesis being discovered over two decades ago, there is a paucity of rhabdoid tumor cases reported in the literature that detail SMARCB1/INI1 expression. Much work remains if we hope to provide additional therapeutic strategies for patients with aggressive SMARCB1/INI1-deficient tumors.

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.

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.

Congenital multifocal rhabdoid tumor: a case with peculiar biological behavior and different response to treatment according to location (central nervous system and kidney)

Atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system and malignant rhabdoid tumor of the kidney (MRTK) may present with different responses to chemotherapy and outcomes. We describe the case of an infant with multifocal rhabdoid tumor with different behavior and response to treatment, depending on the anatomic site.

Dilemmas in the management of patients with vulval epithelioid sarcoma: a literature review

Vulval sarcomas are an extremely rare type of soft tissue tumor, the principal properties of which are unpredictable symptoms and frequent recurrences. This review discusses the management options specific for cases of vulval epithelioid sarcoma. The PubMed, Scopus and Cochrane databases were systematically searched and 28 studies met the inclusion criteria for our narrative review. The mean age of the 31 included patients was 31 years (range: 17-84). Local excision (19 out of 31, 61.3%), radical vulvectomy (8 out of 31, 25.8%) and hemivulvectomy (4 out of 31, 12.9%) were the principal surgical treatments. Radiotherapy and chemotherapy were performed in 8 and 5 patients, respectively. Recurrence of the disease was present in 13 out of 31 (42%). The interval to recurrence ranged from 1 to 48 months. The main location of recurrences was the local tissues, the lymph nodes and the lung. The mean period of follow-up was 38.5 months (range: 2-146 months). Cure was considered to have taken place in 19 out of 31 (61.3%) patients; 10 out of 31 (32.6%) died, and 2 out of 31 (6.4%) at the end of follow-up were alive but not considered cured. The first and principal step for the proper treatment of vulval epithelioid sarcomas is awareness of their existence by the specialist involved. Extensive imaging is proposed for staging, while the creation of a national or international register of patients with this malignancy would enable a more consistent approach to its management.

Vulvar "proximal-type" epithelioid sarcoma: report of a case and review of the literature

Background

The “proximal-type” epithelioid sarcoma is a very rare kind of mesenchimal tumor characterized by the difficulty in histological diagnosis and the very aggressive biological behavior.

Case

We report of a case of a 63 years old woman with a vulvar “proximal-type” epithelioid sarcoma that underwent a radical surgical staging followed by an adjuvant radiotherapy. She is on follow-up care for 14 months and there is no clinical evidence of disease.

Conclusion

Even if quite rare the proximal type epithelioid sarcoma should be regarded as a separate entity of particularly aggressive biologic behaviour. Its diagnosis attracts controversies and criticism related to the surgical approach and the choice of an adjuvant therapy.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1508554852942125

Proximal-type epithelioid sarcoma of the vulva with INI1 diagnostic utility

Proximal epithelioid sarcoma (PES) is an extremely uncommon neoplasm of the vulva with an aggressive behavior. Recently, these authors experienced a case of proximal-type ES in a 41-year-old woman who was admitted for a rapidly growing mass in the right mons pubis. An about-1-cm-sized mass was initially noticed one and a half years earlier. The excised mass, however, was 8 cm in greatest dimension and was relatively well circumscribed. The cut surface was trabeculated, with multifocal hemorrhages and necroses. Microscopically, the tumor consisted of epithelioid rhabdoid cells with vesicular nuclei, large prominent nucleoli, and cytoplasmic eosinophilic globules comparted by thin, fibrous septae. The main differential diagnoses included PES, other sarcomas with epithelioid cells, malignant melanoma, and sarcomatoid carcinoma. The tumor cells were diffusely positive for vimentin and EMA; focally positive for cytokeratin; and negative for CK5/6, CD34, S-100 protein, desmin, and myogenin. INI1 (hSNF5/SMARCB1, a member of the SW1/SNF chromatin remodeling complex located on chromosome 22q11.2) staining clearly showed loss of expression in the tumor cells. Recent studies reported that some ESs also showed INI1 inactivation, as characteristically seen in malignant rhabdoid tumors of infancy. Reported herein is the diagnostic utility of INI-1 on PES and the possible relationship between PES and malignant rhabdoid tumor of the soft tissue, besides a collective review of the reported cases of PES of the vulva and of the current case.