Rare Malignant Transformation of a Granular Cell Tumor: A Case of Recurrent Perianal Lesion With Pulmonary and Lymph Node Metastases.

This report presents the case of a 52-year-old woman with a recurrent perianal mass, initially diagnosed as a benign GCT. Despite surgical resection, the tumor later metastasized to the lungs and lymph nodes, indicating malignant transformation. Imaging and histological analysis confirmed the malignancy, with cellular atypia and metastasis. The patient declined further treatment and passed away shortly thereafter. This case underscores the potential for malignant transformation in GCTs, particularly in recurrent cases. While surgical removal with clear margins remains the standard approach, malignant GCTs often present a poor prognosis due to high rates of recurrence and metastasis, with limited response to chemotherapy and radiation therapy.