Inv(11)(p13p15) and Myf-3(MyoD1) in a malignant extrarenal rhabdoid tumor of a premature newborn

We present a premature newborn of 32 wk of gestation with a congenital mali gnant extrarenal rhabdoid tumor (MERT) on the right shoulder with generaliz ed metastases. Standard histologic, immunohistochemical, molecular and cyto genetic methods were used in the evaluation of diagnostic material. Biopsy of a skin lesion showed the histologic features of a malignant rhabdoid tum or. Cytogenetic analysis of the tumor cells revealed an inv(11)(p13p15) and additionally, an increased expression of myf-3 (myogenic determination fac tor, MyoD1) and PAX3 was detected. These results suggest an origin of the n eoplasm derived from a pluripotent cell with the potential of myogenic diff erentiation. Tumor suppressor genes located on chromosome 11p13 and 11p15 m ay play an important role for malignant rhabdoid tumor development and prog ression.