Weichteilmalignome bei Kindern und Jugendlichen - Pathologische Anatomie und ihre klinische Relevanz

Abstract

Soft tissue malignancies in childhood and adolescence encompass a wide variety of histologically and genetically different tumor entities. In the files of the Kiel Pediatric Tumor Registry, 4,272 soft tissue malignancies were collected since 1977. Rhabdomyosarcomas are by far the most frequent sarcomas (44.6 % of the cases), followed in decreasing order of frequency by the family of Ewing tumors (peripheral primitive neuroectodermal tumors and extraosseous Ewing's sarcomas; altogether 22.3 %), malignant peripheral nerve sheath tumors (8.1 %), synovial sarcomas (5.0 %), leiomyosarcomas (3.2 %), fibrosarcomas (2.4 %), extrarenal malignant rhabdoid tumors (2.0 %), and alveolar soft tissue sarcomas (1.1 %). A further group (11.3 %) includes rare tumors, intermediate fibrohistiocytic tumors, and unclassified sarcomas. Embryonal rhabdomyosarcomas are 2.5 times more frequent than the alveolar rhabdomyosarcomas, which are prognostically unfavorable and located predominantly in the extremities and the trunk. With regard to clinical findings, histology, molecular biology and prognosis, embryonal and alveolar rhabdomyosarcomas have to be considered as two different tumor types. The family of Ewing tumors includes extraosseous Ewing's sarcoma and peripheral primitive neuroectodermal tumors (synonym: malignant peripheral neuroectodermal tumors), the former tumors without and the latter with neural differentiation. Many cases of infantile malignant peripheral nerve sheath tumors and infantile fibrosarcomas are low-grade malignancies and prognostically more favorable than their "adult" counterparts.