Clinico-morphological characteristics of a rare case of pleomorphic cardiac rhabdomyosarcoma

Pleomorphic sarcomas are a group including some of poorly differentiated mesenchymal malignancies, which differ in morphology, molecular and biological properties and clinical outcomes. They are relatively rare tumors comprising, by different assessments, 5 to 7% of all mesenchymal malignancies. The tumors affect soft tissues of the limbs, body, retroperitoneal space and mediastinum. The morphologic substrate of pleomorphic sarcomas is polymorphic tumor cells of fibroblast cell lines, smooth myocytes, rhabdomyoblasts, Schwann cells, etc. Accuracy of morphologic diagnosis of pleomorphic sarcomas ranges between 13 to 26%. In practice it means that histological type of pleomorphic sarcoma is correctly defined only in a quarter of patients. Meanwhile, the importance of defining the histological type before starting the treatment is explained by the fact, that accurate histological and simultaneous molecular characteristics of pleomorphic sarcomas points the way to selective therapy of such tumors. The article presents the results of our observation of a 27-year-old patient with pleomorphic cardiac rhabdomyosarcoma. In this case cardiac tumor, first defined during echocardiography, is one of metastases of pleomorphic rhabdomyosarcoma of neck soft tissues. But at retrospective analysis its primary nature cannot be ruled out. The difficulties of morphologic diagnosis occurring during tumor verification are objective as the diversity of tissues - sources of pleomorphic sarcomas - creates extremely complex histological presentation and exceptionally embarrasses defining the histogenesis of the tumor.