COMPARISON OF CHROMOSOMAL PATTERNS WITH CLINICAL-FEATURES IN 165 LIPOMAS - A REPORT OF THE CHAMP STUDY-GROUP

Soft tissue lipomatous tumors are morphologically heterogeneous. Vario us morphologic features are associated with specific chromosomal patte rns and clinical features such as age, sex, and tumor site, location, and size. Simple lipomas are known to be karyotypically heterogeneous, but this has not been correlated with clinicopathological features. I n 165 cases of solitary soft tissue lipoma, short-term cultures were a nalyzed cytogenetically. The karyotypes were divided into the followin g groups: normal karyotype; 12q13-15 aberrations; 6p rearrangements; 1 3q rearrangements, 8q11-23 aberrations; ring or giant marker chromosom es or both; other aberrations. The tumors were reexamined morphologica lly without knowledge of the karyotypic or clinical data. An abnormal chromosomal pattern wets observed in 129 of 165 cases (78%): in 75 of 90 (83%) lipomas in the extremities and in 43 of 63 (68%) trunk wall l ipomas. Chromosomal aberrations were present in 69 of 90 (77%) subcuta neous tumors and in 59 of 64 (80%) deep tumors. A normal karyotype was twice as frequent in tumors in patients under 30 years of age than in those from older individuals (6 of 16 vs. 30 of 149, 40% resp. 20%). Apart from the finding that normal karyotypes were more common in pati ents younger than 30 years, there was no significant association betwe en cytogenetic pattern and patient sex or age or tumor localization, s ize, or depth. The pathogenetic basis and clinicopathologic relevance (if any) of the cytogenetic subtypes among benign lipomas remain unexp lained. (C) Elsevier Science Inc., 1998.