Granular cell tumor

    Clinical Features:

    • Common benign tumor of putative Schwann cell origin
    • Most often seen in adults, with a female predominance
    • May present in any visceral or cutaneous location
    • Cutaneous lesions are most common on the trunk and extremities.
    • Multiple in up to 10% of cases.
    • Presents as a slow-growing mass, which may be painful, often with a verrucous appearance
    • Excision is usually curative, but the rare infiltrative variants may recur.
    • Rare malignant examples exist.

    Histologic Features:

    • Poorly defined dermal or subcutaneous tumor
    • Composed of nests or trabeculae of large round to oval cells with abundant granular eosinophilic cytoplasm and small, round, uniform, central nuclei
    • Pseudoepitheliomatous hyperplasia of the overlying epidermis is very common in dermal lesions.
    • Positive for S-100, CD68, NSE and NKI-C3 (a putative melanoma marker).  Sometimes also positive for calretinin and α-inhibin.
    • Electron microscopy reveals that the cytoplasm is filled with lysosomes, corresponding to the granules seen on H&E.
    • The criteria for malignancy are not well defined.  Concerning features are size >5 cm, rapid growth, vascular invasion, necrosis, high mitotic index and pleomorphism.

    Cases associated with this book:

  • Granular cell tumor
    Author: Artur Zembowicz M.D. Ph.D.

    Conference: Teaching Collection