Rare case of composite embryonal rhabdomyosarcoma and leiomyosarcoma of the tongue of an adult

The differential diagnosis of embryonal rhabdomyosarcoma (RMS), pleomorphic sarcoma, and leiomyosarcoma remains a challenge because of their overlapping histological presentations, with serious implications on the choice of treatment. We report a rare case of a tumor confined to the tongue in a 22-year-old woman. Clinical, histological, and immunohistochemical data confirmed the diagnosis of a composite tumor of embryonal RMS and leiomyosarcoma based on the presence of spindle-shaped cells within a myxoid background of spherical cells and immunoreactivity to muscle-specific markers (desmin, smooth-muscle actin, muscle-specific actin, myoglobin, and vimentin), RMS-specific myogenin, and leiomyosarcoma-specific h-caldesmon. The lack of immunoreactivity to S-100 and cytokeratin antibodies suggested the absence of melanoma and pleomorphic sarcoma, respectively. Presurgical treatment with a single round of broad-spectrum MAID (mesna, pirarubicin, ifosfamide, and dacarbazine) adjuvant therapy for the advanced soft tissue sarcoma allowed the growth of the tumor from 45mmx38mmx25mmto 45mmx40mmx40mm. Thereafter, subtotal glossectomy was performed. Based on the strong immunoreactivity of the tumor to myogenin, the patient received RMS-specific VAC (vincristine, actinomycin D, and cyclophosphamide) chemotherapy over 6 months. However, metastases to the lungs led to the patient's death. This case highlights the danger of "overdiagnosing" a patient, and the need to select a broad-spectrum adjuvant whenever a diagnosis of composite sarcoma is suspected. (C) 2012 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.