Immature teratoma of vulva in a 15-year-old girl

Backgrounds: Immature teratoma (IT) of vulva (V) has been reported only once. Case report: A 15-year-old girl presented a vulvar tumor, and tumorectomy was performed. The tumor measured 4 cm × 4 cm × 5 cm and multiply cystic. The cysts contained mucinous fluid. The tumor was well demarcated from surrounding tissues and tumorectomy was easy. Microscopically, the tumor was multicystic neoplasm composed of mucin-bearing columnar mature epithelial cells, cellular immature mesenchymal zone beneath the columnar epithelial cells, immature cartilage, and mature connective tissue containing vasculatures. Immunohistochemically, the immature mesenchymal elements of the tumor were positive for p53, Ki67 (labeling = 30%) and vimentin, but negative for smooth muscle actin, myoglobin, HHF-35 caldesmon, and S100 element. No immature neural elements were seen. Since three germ elements were seen and some showed immature features, a diagnosis of IT was made. Conclusions: A very rare case of IT of V is reported. This is the second case of IT in this location.