January 17, 2007

Granular Cell Tumors

Synonyms and related keywords: granular cell myoblastoma, granular cell schwannoma, granular cell neurofibroma, granular neurogenic tumor, congenital epulis, gingival GCT, gingival granular cell tumors, malignant GCT, malignant granular cell tumors, malignant granular cell schwannoma, Abrikossoff tumor


Background: The controversy regarding whether the formation of a granular cell tumor (GCT) is a metabolic, degenerative, or neoplastic process is now resolved; it is a neoplastic process. Lesions are of neural derivation, as supported by immunophenotypic and ultrastructural evidence. Granularity of tumor cells is due to the accumulation of secondary lysosomes in the cytoplasm. This change is rather nonspecific and can be observed in many non-neural tumors, including those arising from smooth muscle, connective tissue, neuroglia, endothelial, and epithelial cells. Features described within this article are those of neural granular cell tumors. Non-neural granular cell tumors are discussed only as differential diagnoses.

Pathophysiology: Granular cell tumors are typically solitary, smaller than 3 cm, and located in the dermis or subcutis and less frequently in the submucosa, smooth muscle, or striated muscle. Granular cell tumors are also found in the internal organs, particularly in the upper aerodigestive tract. Benign and malignant counterparts are known; the latter are rare, comprising fewer than 2% of all granular cell tumors (Franburg-Smith, 1998).


Mortality/Morbidity: Again, the lesion is uncommon, and, as with prevalence figures, mortality and morbidity rates are not available.

Race: Granular cell tumors appear to be more common in black persons. Multiplicity of lesions is definitely more common in black persons. Up to 10% of granular cell tumors are multiple (ie, 2-4).

Sex: A slight female predominance exists, with an estimated female-to-male ratio of approximately 3:2.

Age: Granular cell tumors affect persons of varying ages, and the range is wide. Most patients are middle-aged, with a peak incidence in the fourth through sixth decades of life.






Other Problems to be Considered:

Clinical differential diagnoses vary depending on the site of the granular cell tumor. Pathologic differential diagnoses are discussed in Workup.


Lab Studies:

Imaging Studies:

Staging: Universally recommended and accepted staging schemes specific for granular cell tumors do not exist. A general staging scheme developed by the American Joint Committee on Cancer for use with other soft tissue tumors may be followed.


Medical Care: Radiation and chemotherapy are not needed for benign lesions and are not effective for malignant lesions.

Surgical Care: If resection is complete, local surgical excision is curative for benign granular cell tumors. Wide en bloc excision is recommended for malignant lesions.

Consultations: Seek consultation with a site-specific surgeon.

Diet: Generally, no diet restrictions are necessary.

Activity: Generally, no activity restrictions are necessary.


The primary mode of treatment is surgical, not medical.





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