Unexpected Discovery of Myoepithelioma-Like Tumor of the Vulvar Region After Trauma: A Rare Case Report and Systematic Review of the Literature.

Myoepithelioma-like tumor of the vulva region (MELTVR) is a low-grade mesenchymal neoplasm and mainly arises in the subcutaneous tissue of the vulva and surrounding regions in adult females. Here, a case of MELTVR is reported and the literature is systematically reviewed to shed light on this rare disease. The patient was a 46-year-old female who presented with a lump in the right vulva region after local trauma. On microscopic examination, the tumor cells displayed epithelioid or spindled morphology with fine amphophilic cytoplasm and uniform nuclei with vesicular chromatin. Immunohistochemical staining showed that tumor cells were positive for vimentin and calponin but negative for S100 protein, glial fibrillary acidic protein, AE1/AE3, and CD34. INI1/SMARCB1 expression was absent in the tumor nuclei. Fluorescence in situ hybridization revealed no EWSR1 or FUS gene rearrangements. These findings confirm the diagnosis of MELTVR. Although the biological behaviors of MELTVR remain incompletely understood, recognition of its characteristic morphologic and immunophenotypic profiles will aid in distinguishing it from potential histological mimics better.