July 2018
- 38 year old female presented with a 2 cm mass on her abdomen.
- Cyst
- Dermatofibroma
Sections show sheets of epithelioid cells with abundant eosinophilic cytoplasm present throughout the dermis
Higher magnification shows the lesional cells have finely granular cytoplasm
Granular cell tumor
- Granular cell tumors are bengin neoplasms that often arise in the oral cavity, particularly the tongue, but occur commonly in the skin and subcutaneous tissue
- These tumors are believed to arise from Schwann cells or a “neural crest-derived peripheral nerve-related cell”
- Pseudoepitheliomatous hyperplasia can be seen overlying the tumor and may be mistaken for squamous cell carcinoma on superficial biopsies
- Granular cells tumors are composed of sheets and aggregates of epithelioid cells with abundant eosinophilic and finely granular cytoplasm
- Large cytoplasmic granules called pustulo-ovoid bodies of Milian are often identified
- The granularity of the cytoplasm is caused by accumulation of lysozymes
- The tumor cells are strongly positive for S100 and CD68 by immunohistochemistry; MITF and NKI/C3 can also be positive
- Malignant transformation is exceedingly rare but such tumors may metastasize
- Surgical excision is curative for benign lesions
- Some lesions may locally recur even with clear margins
- Granular cell tumors are bengin neoplasms that often arise in the oral cavity, particularly the tongue, but occur commonly in the skin and subcutaneous tissue
- Granular cells tumors are composed of sheets and aggregates of epithelioid cells with abundant eosinophilic and finely granular cytoplasm
- The tumor cells are strongly positive for S100 and CD68 by immunohistochemistry; MITF and NKI/C3 can also be positive
- Surgical excision is curative for benign lesions