[21] Consistent t(1;10) Abnormality in Both Myxoinflammatory Fibroblastic Sarcoma (MIFS) and Hemosiderotic Fibrolipomatous Tumor (HFLT).

Cristina R Antonescu, Lei Zhang, Gunnlaugur P Nielsen, Andrew E Rosenberg, Paola Dal Cin, Christopher D Fletcher. Memorial Sloan-Kettering Cancer Ctr, New York, NY; Massachusettes General Hospital, Boston; Brigham & Women's Hospital, Boston, MA

Background: Despite their common predilection for superficial acral location and frequent local recurrences, MIFS and HFLT have distinct morphologic appearances. Only recently cytogenetic studies have identified the presence of an identical t(1;10)(p22;q24) in 5 cases of MIFS and 2 of HFLT, suggesting a pathogenetic link between these two entities.
Design: In order to investigate further the potential relationship between these lesions, as well as to determine the incidence of t(1;10) in a larger group of patients, we subjected 22 cases, representing 6 MIFS, 13 HFLT, and 3 cases with mixed morphology, to molecular and cytogenetic analysis. FISH analysis using custom BAC probes for TGFBR3 on 1p22 and MGEA5 on 10q24 was performed in all cases. Conventional karyotyping was also performed in one HFLT and two cases with mixed MIFS/HFLT histology.
Results: Overall 81% of cases (4/6 MIFS and 11/13 HFLT) showed gene rearrangements in both TGFBR3 and MGEA5. A consistent unbalanced pattern was identified by FISH, with deletion of centromeric fragment of TGFBR3 and telomeric portion of MGEA5. All three cases with features of MIFS and HFLT were positive. Two otherwise typical cases from each group, one each in the arm and leg, were negative for rearrangement in both genes by FISH. Cytogenetic analysis performed in three cases confirmed the presence of a t(1;10)(p22;q24), as well as loss of chromosome 3 material.
Conclusions: The high incidence of t(1;10) in both MIFS and HFLT reinforce the likely shared pathogenetic relationship of these two lesions. Furthermore, the co-existence of both components either synchronously within the same tumor or metachronously in primary/subsequent recurrence, suggest that they represent different morphologic variants of the same entity. FISH analysis for the presence of TGFBR3 and MGEA5 rearrangements can be applied as a reliable molecular test when confronted with limited biopsy material or a challenging diagnosis.
Category: Bone & Soft Tissue

Monday, February 28, 2011 11:15 AM

Platform Session: Section F, Monday Morning


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