[Peripheral primitive neuroectodermal tumor -- PNET].

The authors describe three cases of peripheral primitive neuroectodermal tumor. The tumor was found in soft tissues of the crus, shoulder girdle and perineum, and was also located paravertebrally and epidurally at the level of L1-L2 vertebrae. Radiological findings were not specific for this disease. The results of imaging methods (sonography, CT, MRI, DSA) were important for the assessment of tumor size, its boundary and invasion of the surrounding tissues, and for the evaluation of tumor response to therapy and detection of recurrent disease. The PNET diagnosis was based on immunohistochemical, biochemical and cytogenetic examinations. One patient died 5 months after the first clinical signs were manifested; the two patients surviving for 2 and 1 3/4 years after first sign manifestation, respectively, remained in the care of cancer specialists. Key words: skeletal Ewing's sarcoma, extra-skeletal Ewing's sarcoma, Ewing's sarcoma family of tumors, peripheral primitive neuroectodermal tumor.