Uncovering an Uncommon Diagnosis in a Child - Granular Cell Tumor in the Left Leg

Abstract

Granular cell tumor (GCT) is a rare benign tumor of Schwann cell origin that typically impacts adults and frequently occurs in the head and neck. Its manifestation in the pediatric population, particularly within the lower extremities, is exceedingly rare and may pose diagnostic challenges. We present a unique case involving a 12-year-old girl with an insidiously enlarging, non-tender swelling on the anterior aspect of the left leg. Preliminary imaging and fine-needle aspiration cytology (FNAC) failed to provide conclusive evidence, prompting surgical biopsy for definitive evaluation. Histopathological examination revealed abundant granular eosinophilic cytoplasm and small, centrally located nuclei, characteristic of GCT. Imnunohistochemical analysis demonstrated strong S100 protein positivity. Further substantiating the diagnosis, with a Ki-67 proliferation index of 5% indicating a low mitotic rate. This example highlights the essential requirement of using GCT in the differential diagnosis of pediatric soft tissue lesions, especially those arising in atypical anatomical locations. Early recognition and histological confirmation are essential for appropriate management and to avoid over-treatment.