Vulvar granular cell tumor

Abstract

Granular cell tumors are rare, usually benign, soft tissue neoplasms of neural origin. They occur more often in females than males, the peak age incidence is in the fourth through fifth decades. They can occur anywhere in the body with up to 15% situated in the vulva. The commonest presentation is as an asymptomatic mass. Microscopic findings are usually sufficient, but immunohistochemistry can also be helpful in confirming the diagnosis. The vulvar tumors are benign in 98% of cases with 2% reported as malignant. In this case report we describe a woman with a granular cell tumor confirmed by biopsy who underwent excision of the mass but with focal extension to the resection margin on microscopy. Our recommendation of re-excision was declined. Since it is not uncommon with these tumors to find groups of tumor cells extending beyond the macroscopic limits of growth, we conclude that it is advisable to have margins assessed intraoperatively by frozen section such that further excision can be performed for positive margins. Our patient has been followed for 18 mo without recurrence, should the tumor recur, re-excision, with frozen section control, is indicated. Recurrence rates are reported as 2%-8% with clear margins and 20% with positive margins.

Keywords: Granular cell tumor, Vulvar tumor, Vulvar neoplasm

Core tip: Granular cell tumors are rare, usually benign, soft tissue tumors of neural origin. They can occur anywhere in the body with up to 15% situated in the vulva. Malignancy has been reported in about 2% of cases. We report a woman with a granular cell tumor of the vulva who underwent tumor excision but with focal extension to the resection margin on microscopy. Recurrence rates are 2%-8% with clear margins and 20% with positive margins. We conclude that intraoperative assessment by frozen section is advisable such that further excision can be performed for positive margins.