Granular cell tumor: rare location and literature synopsis.

Summary: Granular cell tumor is a rare clinical entity derived from Schwann cells. This tumor was first described by Abrikossoff in 1926. Most are found in the oral cavity, especially the tongue. The vulvar location is extremely rare, being around 7% of the cases. The average age of presentation is 40 to 50 years, but the tumors may arise in children. There is a slight risk of malignant transformation at the rate of 2%. Here, we reported a 28-years-old female, presented with progressively enlarged, solitary nodule on her left labia majora in the last 9 months. On histology, it showed non-encapsulated tumor mass in the dermis, composed of large cells with abundant eosinophilic granular cytoplasm. Immunohistochemical staining revealed strong expression of S100. Based on the biopsy result, the patient underwent local complete resection of vulvar tumor under local anesthesia. Granular cell tumors are uncommon soft tissue tumors, approximately 50% occur in the tongue. However, in this case, a rare presentation of GCTs on the vulva of a 28-years-old young female which was successfully treated with surgical excision. In short, we think that GCT should be considered as one of the differential diagnoses of solitary genital mass at young ages.