Leiomyosarcomas of the oral cavity: An unusual topographic subset easily mistaken for nonmesenchymal tumours

Aims: Oral leiomyosarcoma is rare and poorly documented. We aimed to characterize these lesions clinicopathologically in order to facilitate their distinction from other spindle cell neoplasms in the oral cavity. Methods and results: Ten cases of oral leiomyosarcoma were retrieved and studied histologically and immunohistochemically, Clinical data were obtained from referring pathologists and prior literature concerning 46 comparable cases was reviewed. Nine out of 10 cases occurred in adults; 50% arose in the jaws and four showed bone involvement. Histological appearances were similar to leiomyosarcomas elsewhere. In addition to myogenic markers, two cases were also keratin-positive. Four patients developed local recurrence or metastatic disease and three died of tumour (median follow-up 37 months). Conclusions: Leiomyosarcoma is under-recognized in the mouth, often being mistaken for a spindle-celled epithelial neoplasm. Aside from an unusual but infrequent tendency to spread to lymph nodes and a location-specific differential diagnosis, its clinicopathological features are comparable to leiomyosarcomas at other locations.