Case reports in gastrointestinal medicine Granular cell tumor: A rare entity of the perianal region
Granular cell tumor is a pathological entity that was first described by Abrikossof in 1926. Many locations were described. The most frequent one is the buccal mucosa especially on the tongue, dermis and subcutaneous tissue. Granular cells tumor is rarely located in the perianal region . Granular cell tumors often occur between the 4th and 6th decades with a male predominance that can reach up to 68%. Although a malignant variant of this tumor exists, it barely presents 2% of all cases. The diagnosis of malignancy requires an accurate analysis of the histological feature and investigations in order to identify metastases. The basic treatment is surgical excision with local recurrence being the only possible complication when the resection is incomplete. In our work, we report the case of a granular cell tumor of the perianal region that was clinically taken for a squamous cell carcinoma. 6 months after surgery, the patient had a good evolution, without any sign of local recurrence. We also discuss the most important features of this entity.
Our patient is a 52 years old female, married, with no clinical or surgical morbidities. No relevant family neoplastic history was found. She complained for about one year of perianal pain, without diarrhea, abnormal evacuations, rectal bleeding or fever. The patient has previously received anti-hemorrhoid therapy for more than 2 months without any improvement. She was then admitted in our hospital, where rectal examination has revealed a right perianal nodule without local inflammatory changes. No hemorrhoids or other lesions were identified. General examination of the patient was normal. We performed a pelvic MRI with contrast, which identified a lesion of the ischioanal fossa that appeared isointense on T1 weighted images and hypo intense on T2 weighted images. The lesion showed progressive and delayed enhancement on T1 weighted images with fat saturation with contrast. It was in an intimate contact with levator ani and gluteus maximus mascules. Other investigations included colonoscopy, laboratory tests and chest X ray and were found to be normal. An entire macroscopic surgical excision and the surrounding subcutaneous tissue under local anesthesia were performed. The used local anesthetic was Marcaine 25%, with a security marge of 0.5 cm around the mass. Pathological examination of the resection specimen, a 5,5x4,5x2cm of subcutaneous tissue, has revealed a diffuse proliferation of large cells. These cells have a polygonal oxyphilic granular cytoplasm and a regular hyperchromatic, often pyknotic nucleus. The tumoral stroma was essentially fibrous without an inflammatory infiltrate. No mitotic activity neither necrosis was observed. The proliferation locally invades skeletal muscle. The cells have a PAS + cytoplasm on histochemical study. On immunohistochemical study, tumor cells were positive to CD68 and S100 protein. 6 months after surgery, the patient had a good evolution, without any sign of local recurrence.
Journal of Tumor Research