82 Rare Case of Atypical Multifocal Cutaneous Granular Cell Tumor

Introduction/Objective Granular cell tumors (GCTs) are rare soft tissue neoplasms typically classified as benign and originating from neural (Schwann) cells. The atypical variant of these tumors is less common, existing in a gray area between benign and malignant forms, which makes its biological behavior unpredictable. We report a case of multifocal cutaneous granular cell tumor with atypical features. Methods/Case Report A 28-year-old male presented with two painless nodules on the left upper lateral back and one on the right anterior lateral chest wall. Gross examination of the excised nodules revealed soft, rubbery, tan-colored tissue, with maximum dimensions up to 2.5 × 0.7 × 0.5 cm. Microscopically, the back lesions demonstrated a proliferation of intermixed spindle and epithelioid cells with granular cytoplasm, eccentric nuclei, and inconspicuous nucleoli. The nodule from the right anterior lateral chest wall showed numerous proliferating granular cells with areas of spindling and prominent nucleoli. Immunohistochemical studies revealed strong positivity for S100, SOX-10, and calretinin, with negative staining for HMB-45 and Melan A. These findings were consistent with atypical granular cell tumors. Tumor cells were identified at the surgical margins, requiring re-excision to achieve complete removal with confirmed negative margins. Results NA Conclusion Atypical multifocal cutaneous granular cell tumors present a diagnostic and management challenge due to their potential for local recurrence and malignant transformation. Complete surgical excision with negative margins is essential to reduce the risk of recurrence and close clinical follow-up is recommended.