Multiple granular cell tumors with metachronous occurrence in tongue and vulva. Clinicopathological and immunohistochemical study.

Granular cell tumor (GCT) usually occurs as a single tumor, although sometimes multiple lesions can occur. In present report we analyze the clinicopathological and immunohistochemical features of a multiple GCT involving the tongue of a 14-year-old girl, with no other abnormalities, with a metachronous occurrence of a second GCT in vulva, after a period of 10 years. Both tumors revealed S-100, vimentin and CD57 positivity. In addition, over expression of calretinin was observed in tumor cells located in the vicinity of pseudoepitheliomatous hyperplasia (PEH) of the tongue. Tumor vasculature situated close to the PEH showed marked CD105 reactivity, data not described so far, suggesting an interaction between PEH cells and underlying stroma, since GCT completely lacks CD105 vessels. Our study emphasizes that patients with GCT, especially young patients, should be followed long-term, looking for multiple tumors or other abnormalities suggestive of a systemic syndrome, given the associations described in multiple GCT.