A rare case of granular cell tumor of the anal region: diagnostic difficulty to masses in the anal area

An Uncommon Perianal Mass in a Girl: A Diagnostic Challenge

A 15-year-old female presented with a two-month history of a tender perianal nodule, which was aggravated by sitting or pressure. She denied having any systemic symptoms. Examination revealed a well-defined, erythematous-to-gray nodule measuring 3 × 3 cm, featuring a corrugated surface at the lateral end. Histopathology showed large polygonal cells with abundant granular eosinophilic cytoplasm and small, uniform nuclei. Immunohistochemical staining was strongly positive for S-100 protein and neuron-specific enolase, confirming the diagnosis of a granular cell tumor (GCT). GCT is a rare, usually benign neoplasm of Schwann cell origin, with perianal involvement being extremely uncommon, especially in pediatric patients. Although most cases are asymptomatic, a perianal GCT can cause discomfort and may require surgical excision with sphincter preservation. While malignant transformation is rare, close monitoring is advised. This case highlights the diagnostic challenges of GCT in unusual locations and underscores the importance of histopathology and immunohistochemistry for accurate diagnosis and management.

A rare case of perianal granular cell tumor: case report and literature review

Granular cell tumor (GCT) is a rare submucosal neoplasm most commonly localized in the oral mucosa; with one-third of all cases found in the tongue, with less than 30 cases of perianal GCT reported in the literature, making it a rare anal neoplasm. Wide local excision is the gold standard of treatment and follow-up includes annual colonoscopy due to the high incidence of reoccurrence. Here we describe a rare case of benign perianal GCT in a 29-year-old female who presented asymptomatically; however, pathology report revealed a S100 positive immunostaining pattern. GCT is an important differential to be included when evaluating a patient with an asymptomatic perianal submucosal lesion. Since GCT and Squamous Cell Carcinoma present with similar pseudoepitheliomatous hyperplasia of the epithelium it is important that a biopsy and immunohistochemical analysis be performed to allow for accurate diagnosis and appropriate treatment.

Unexpected Presentation of Perianal Granular Cell Tumor in a Young Woman

Granular cell tumors originate from Schwann cells of the soft tissues and are rarely observed in the perianal region. Often, correct diagnosis can be challenging owing to nonspecific clinical symptoms and imaging characteristics, as well as its ability to mimic other malignant lesions histologically. We describe the case of a previously healthy 36-year-old woman who presents with a slow growing, painless lump in her perianal region who underwent surgical excision and was found to have a granular cell tumor on microscopic evaluation. This case highlights the importance for radiologists, pathologists, surgeons, and other health care providers to be aware of this rare neoplasm and consider it in the differential diagnosis when encountering perianal masses.