Synchronous subcutaneous granular cell tumours, a rare presentation.

Area of Science:

• Oncology
• Pathology
• Dermatology

Background:

• Granular cell tumors (GCTs) are rare, typically benign neoplasms derived from Schwann cells.
• They most commonly occur in the head and neck region and are usually asymptomatic.

Observation:

• A 36-year-old woman presented with a large, symptomatic left flank mass and multiple synchronous subcutaneous masses on the breast, auricle, and cheek.
• Initial diagnosis was confirmed as granular cell tumor via core needle biopsy.

Findings:

• Histopathological and immunohistochemical analysis of excised masses confirmed non-malignant granular cell tumors.
• Multifocal GCTs are present in 5-16% of patients, though this presentation with extensive subcutaneous involvement is unique.
• Malignancy, rare in GCTs (approx. 2%), is indicated by high mitotic rate, necrosis, and pleomorphism.

Implications:

• Definitive histopathological diagnosis is crucial for granular cell tumors, as frozen section analysis is often unhelpful.
• Surgical resection is the primary treatment for symptomatic GCTs, followed by surveillance.
• This case expands the understanding of GCT presentation and multifocality.