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 charac terize these lesions clinicopathologically in order to facilitate their dis tinction from other spindle cell neoplasms in the oral cavity. Methods and results: Ten cases of oral leiomyosarcoma were retrieved and st udied 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 t he jaws and four showed bone involvement. Histological appearances were sim ilar to leiomyosarcomas elsewhere. In addition to myogenic markers, two cas es 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 m istaken for a spindle-celled epithelial neoplasm. Aside from an unusual but infrequent tendency to spread to lymph nodes and a location-specific diffe rential diagnosis, its clinicopathological features are comparable to leiom yosarcomas at other locations.