The t(1;10)(p22;q24) TGFBR3/MGEA5 translocation in pleomorphic hyalinizing angiectatic tumor, myxoinflammatory fibroblastic sarcoma, and hemosiderotic fibrolipomatous tumor

Context.—Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts, hemosiderotic fibrolipomatous tumor (HFLT), and myxoinflammatory fibroblastic sarcoma (MIFS) are 3 distinct entities of low-grade spindle cell mesenchymal neoplasm. These tumors have similar clinical presentations and partially overlapping but distinctive pathologic features. A recurrent translocation, t(1;10)(p22;q24), has been detected in a subset of PHAT, HFLT, MIFS, and HFLT/MIFS hybrid cases. Translocation t(1;10)(p22;q24) involves transforming growth factor b-receptor 3 (TGFBR3) and meningioma-expressed antigen 5 (MGEA5) genes on chromosomes 1p22 and 10q24, respectively. However, the percentage of translocation in PHAT, HFLT, and MIFS varies significantly among different studies. The relationship among these tumors has been a controversial topic among experts. Objective.—To discuss the diagnostic and functional significance of translocation t(1;10)(p22;q24) TGFBR3/ MGEA5 rearrangement in HFLT, PHAT, and MIFS. Data Sources.—PubMed was used for this study. Conclusions.—Diagnosis of HFLT, PHAT, and MIFS is challenging because of a lack of unique morphologic, immunophenotypic, molecular, and cytogenetic markers. The recurrent t(1;10)(p22;q24) translocation and/or TGFBR3/MGEA5 rearrangement was reported in 55 patients, with a relatively even distribution among HFLT, PHAT, and MIFS (17 HFLT, 15 MIFS, 13 MIFS/HFLT, and 10 PHAT). This indicates that current morphology-based diagnostic criteria do not identify reliably the subset of soft tissue tumor with t(1;10) translocation. Genetic heterogeneity of these tumors is supported by the recent detection of a mutually exclusive, second recurrent genetic change, t(7;17) TOM1L2-BRAF translocation or BRAF amplification, in a subset of MIFS.