Leiomyomatous Hamartomas of the Oral Cavity: Clinicopathological and Immunohistochemical Features of 4 Cases and Literature Review.

Objective. To present 4 new cases of oral leiomyomatous hamartomas (OLH), describing its clinical, microscopical, and immunohistochemical features, and a literature review. Methods. The OLH cases were retrieved from the files of 2 Brazilian and 1 Peruvian oral pathology services. Clinical data were obtained from the pathology reports. Microscopical features were reviewed, and immunohistochemical reactions were performed. A review of the English-language literature about OLH was done. Results. The sample was composed of 3 females (4-, 10-, and 15-year-old) and 1 male (3-year-old). Three cases affected the dorsum of the tongue and one the incisive papilla, and all presented sessile or pedunculated smooth nodules. Microscopically, the lesions were composed of varying-size fascicles of smooth muscle fibers in a fibrous connective tissue background. Immunohistochemistry revealed positivity of the smooth muscle bundles for myogenic markers. The English-language literature review revealed 38 OLH cases reported, most were congenital or diagnosed up to 5 years old. The main locations were tongue and anterior maxilla. Conclusions. Although OLH is a rare lesion, it must be considered in the differential diagnosis of midline tongue or maxillary masses in newborns, infants, and youngsters.