Müller-S1, Amann-U1, Müller-AM2, Kirkpatrick-CJ2, Metze-D1, Luger-T1 (1Clinic of Dermatology of the Westfalian Wilhelms-University, Münster; 2Institute of Pathology of the Johannes-Gutenberg-University, Mainz)
Introduction : The granular-cell tumor, first described by Abrikossoff in 1926, is a relatively uncommon usually benign lesion that may occur in almost any part of the body but appears to be most common in the tongue.
Case report : A 14 year old girl presented with a solitary nodular tumor of 1 cm in diameter at the right rim of the tongue, which she had noted for four months. The tumor was completely excised and the patient seen 4 weeks and 6 months postoperatively. There were no recurrent lesions. Histologically, there was a fairly well circumscribed tumor located in the submucosa and involving the skeletal muscle of the tongue. The tumor cells were round to polygonal with small dark centrally placed nuclei and a coarsely granular eosionophilic cytoplasm, staining weakly with PAS. The cells were distributed in large nests with occasional slender connective fibrous tissue septae. The overlaying squamous epithelium showed a marked acanthosis and parakeratosis. Immunhistochemically there was a positive staining of the tumor cells for NSE and S-100, but no reactivity with antibodies against desmin, keratin, vimentin, HMB 45, F VIII.
Discussion : The granular cell tumor is mainly found in patients in the fourth to sixth decades of life, seldom in children. It was described for the first time in 1926 by Abrikossoff as ”granular cell myoblastoma” as he regarded the tumor arising from myoblasts in response to trauma or inflammation. Today a neural orgin, especially Schwann cell origin, is supported, the latter by the positive staining of the cells for S-100, which is absent in perineural cells and endoneural fibroblasts. The prominent epithelial hyperplasia over the tumor may sometimes be mistaken for squamous cell carcinoma.