Inflammatory myofibroblastic tumor with HMGIC rearrangement

Inflammatory pseudotumors or inflammatory myofibroblastic tumors (IMT) are lesions of extreme heterogeneity showing a highly variable mixture of bland -looking spindle cells,inflammatory cells, and collagen fibers. We describe our results of molecular cytogenetic and rapid amplification of cDNA ends (RACE-PCR) studies on an IMT characterized by a translocation involving 12q 15. Chromosomal aberrations involving this region are very frequent among o ther benign tumors such as lipomas, uterine leiomyomas, or pulmonary chondr oid hamartomas. Recently, we have shown that, by these structural chromosom al aberrations, the HMGIC gene is affected. Fluorescence in situ hybridizat ion (FISH) analysis and 3' RACE-PCR on cells of the present case of an infl ammatory myofibroblastic tumor indicated an intragenic rearrangement of HMG IC, resulting in an aberrant transcript of that gene.. Clonal cytogenetic a berrations have been described in very few cases of IMT. The results presen ted herein indicate that this case of IMT represents a true benign mesenchy mal neoplasm associated with, or due to, a rearrangement of HMGIC. (C) Else vier Science Inc., 1999. All rights reserved.