Paraganglioma of the vulva: a case report and review of the literature.

Paraganglioma is a neuroendocrine neoplasm, which is extremely rare in the vulva and only one case has been reported. Here we present a case of vulvar paraganglioma in a 48-year-old woman and a literature review. The patient found a lump located in the genitals below the symphysis pubis 3 months before presentation when she complained that the lump was increasing in size. A 3.2 cm x 2.3 cm x 1.5 cm nodule was excised from subcutaneous soft tissue in the vulva. Microscopy showed a diversity of cell morphologies and structures in the rich vascular network of the tumor separated the chief cells into round cell nests (Zellballen pattern). Some areas of the tumor presented epithelioid and spindle-shaped cells with increased cell density and indistinct structural characteristics. Hyaline degeneration of collagen fibers or mucoid degeneration was found in tumor interstitium. Immunohistochemical staining showed diffused expression of synaptophysin in the chief cells, focal expression of S-100 protein in the sustentacular cells and high expression of CD34 in the vascular components. Based on morphological and immunohistochemical results, a rare paraganglioma of the vulva was diagnosed.