Fibrous hamartoma of the tongue: report of a case with immunohistochemical and ultrastructural studies.

The case of an 8-month-old female with fibrous hamartoma of the tongue is reported with immunohistochemical and electron microscopic findings. An elastic hard mass at the base of the tongue gradually enlarged, causing dysphagia. The tumor was excised by CO2 laser. Under light microscopy, the tumor was observed as composed of fibroblast-like cells, fibrocollagenous bundles and striated muscle tissues. The majority of the cells were immunoreactive for vimentin. Electronmicroscopically, they contained numerous intermediate filaments, some had intercellular microvilli and cilia (9 + 2 type). These findings revealed that the cells of the fibrous hamartoma in our case may possess both mesenchymal and epithelial properties.