Adult cutaneous alveolar rhabdomyosarcoma on the face diagnosed by the expression of PAX3-FKHR gene fusion transcripts.

A 26-year-old woman presented with an indurated subcutaneous tumor on her left cheek. The histology was compatible with alveolar rhabdomyosarcoma, but immunohistochemistry showed that the tumor cells were negative for desmin, alpha-smooth muscle actin and alpha-Sr-1, but were positive for CD56, vimentin and myogenin. The diagnosis of alveolar rhabdomyosarcoma was confirmed by the detection of PAX3-FKHR fusion gene transcripts in the paraffin-embedded tumor tissue. The tumor was unresponsive to chemotherapy with pirarubicin, carboplatin and ifosfamide, and the patient died 9 months after the diagnosis. This adult case of an alveolar rhabdomyosarcoma primarily occurring on the face is very rare, and the detection of PAX3-FKHR fusion gene transcripts was useful for diagnosis of the disease.