Lymphadenopathic form of alveolar rhabdomyosarcoma: A case report.

We report the case of a special form of rhabdomyosarcoma called "lymphadenopathic" which was reported only two times in the literature. This lymphadenopathic alveolar RMS shows lymph nodes as clinical manifestation mimicking lymphoma with an unknown primary neoplasm. In the case we report, clinical examination, and radiological studies revealed superficial and deep located lymph nodes in association with bilateral pleural effusion. Conventional histological examination showed lymph node infiltration by a metastatic tumour having alveolar pattern. Some of tumour cells were round with multilobed off-centred nucleus and eosinophilic cytoplasm containing fibril material with longitudinal and transverse striation indicating a muscle nature of the tumour proliferation. The immunohistochemical study showed intense and diffuse immunoreactivity of tumour cells for vimentin and a discreet immunostaining by desmin. These findings were compatible with the diagnosis of lymph node metastasis by alveolar rhabdomyosarcoma.