Resumen de Primary leiomyosarcoma of the mandible: a case report

João de Jesus Viana Pinheiro, Sérgio de Melo Alves Júnior, Edson Okuda, Waldir Antonio Jorge, Ruy Gastaldoni Jaeger, Ney Araujo

• The aim of this article is to describe a case of leiomyosarcoma of the mandible with immunohistochemical analysis that was useful in making the final diagnosis.

  A 40-year-old woman was referred to the Stomatology Clinic of São Paulo Tatuapé Hospital, , for evaluation of a lesion on the left side of the mandible. This lesion presented a fast growth in the last 6 months. Intraoral examination showed a firm, fixed, red colored mass measuring, approximately 60-mm in diameter. No lymph nodes involvement was found.

  The radiographic examination showed a lytic lesion showed ill-demarcated radiolucent with facial and lingual cortical bone destruction. Microscopic examination of the mandibular lesion showed a neoplasm composed by interlacing fascicles of spindle-shaped cells. Most of the cells presented a blut-ended elongated shape. A marked cellular pleomorphism was observed, represented by cells with irregular shape and abundant eosinophilic cytoplasm. Nuclei were large, hyperchromatic, either vacuoled or cigar-shape. The cytoplasm of the cells stained red with Masson’s trichrome stain.

  Neoplastic cells expressed vimentin, smooth-muscle actin, HHF-35 and desmin. These findings were consistent with the diagnosis of leiomyosarcoma.