METASTATIC RETROPERITONEAL PARAGANGLIOMA IN A 16-YEAR-OLD GIRL - CASE-REPORT, MOLECULARPATHOLOGICAL AND CYTOGENETIC FINDINGS

Retroperitoneal paraganglioma is a rare tumor, especially occurring in childhood and adolescence, with a marked tendency to become biologica lly malignant. It has not been possible to predict the clinical outcom e of paraganglioma patients by conventional histology, hence malignanc y can only be demonstrated by the occurrence of metastatic lesions. Cu rrently, only limited information on the genetics of this tumor is ava ilable. We report on a 16-year-old girl with a large retroperitoneal p araganglioma and an osseous metastasis to the first lumbar vertebra. I n addition to morphological and immunohistochemical examinations, a mo lecular cytogenetic analysis was performed. Comparative genomic hybrid ization (CGH) revealed imbalanced chromosomal aberrations with a loss of chromosome Ip and a gain of Iq, indicating isochromosome Iq. A loss of chromosome 3 as well as low-level gains of chromosomes 4, 5, 6q, 1 1q and 13q were detected. A PCR-based microsatellite analysis of Ip co nfirmed the loss of heterozygosity, including NB1 and NB2 putative tum or-suppressor gene regions. Telomerase activity, which is found in the majority of malignant tumors, could not be detected. The case present ed here is the first more comprehensive molecular genetic analysis of a sporadic malignant paraganglioma.