Synchronous oral leiomyosarcoma and squamous cell carcinoma

An unusual case of synchronous squamous cell carcinoma and leiomyosarcoma o f the oral cavity is reported in a patient without any identified environme ntal risk or predisposing factors. The invasive squamous cell carcinoma inv olved the tongue, whereas the leiomyosarcoma was located in the soft palate . No immunostaining was found for human papillomavirus or Epstein-Barr viru s, and in situ hybridization showed negativity for human papillomavirus DNA within the tumor cells. Alterations of bcl-2, c-erb-b2 and Rb oncoproteins were not found immunohistochemically. Overexpression of p53 was detected b y immunohistochemistry in both tumors, but p53 gene mutations were not foun d by polymerase chain reaction. Neither loss of heterozygosity of p53 nor m icrosatellite instability was detected in this patient. The smooth muscle n ature of the leiomyosarcoma was confirmed by immunohistochemical methods. T o our knowledge, synchronous smooth muscle and epithelial oral tumors have not previously been reported.