title: The genetics of interdigitating dendritic cell sarcoma share some changes with Langerhans cell histiocytosis in select cases.
abstract: Histiocytic disorders have been noted to have evidence of transdifferentiation; examples of cases with combinations of different lineages have been shown. In our index case, we identified interdigitating dendritic cell (IDC) differentiation in a case of Langerhans cell histiocytosis (LCH). Little is currently known about the genetics of IDC sarcoma (IDCS) because they are exceedingly rare. Using array comparative genomic hybridization (aCGH), we evaluated 4 cases of IDCS and compared them with our index case, as well as genetic abnormalities previously found in LCH. Four cases of paraffin-embedded samples of IDCS and 1 case of LCH with IDC differentiation were evaluated using aCGH. Array CGH results showed no abnormalities in a case of LCH with interdigitating cell differentiation. In 3 of 4 cases of IDCS, genetic abnormalities were identified; 1 case had no identifiable abnormalities. Interdigitating dendritic cell sarcoma case 1 had gains of 3q and 13q; IDCS case 2 had trisomy 12; IDCS case 3 had deletions of 7p, 12p, 16p, 18q, 19q, and 22q; and IDCS case 4 had no detectable abnormalities. Our index case, LCH with IDC differentiation, showed no abnormalities by aCGH. A number of LCH cases do not have detectable genetic abnormalities. In contrast, 3 of 4 cases of IDCS evaluated had identifiable abnormalities by aCGH. Furthermore, 2 of these shared abnormalities, albeit of large genetic regions, with published abnormalities seen in LCH. No recurrent abnormalities were identified in the IDCS cases. However, the possibility of a relationship between IDCS and LCH cannot be entirely excluded by these results.
authors: Clarient/GE Healthcare, Aliso Viejo, CA; MD Anderson Cancer Center/University of Texas, Houston, TX. Electronic address: domalley@clarientinc.com.
authors: Dennis P
authors: DP
authors: O'Malley
authors: Lawrence
authors: L
authors: Zuckerberg
authors: Lauren B
authors: LB
authors: Smith
authors: Todd S
authors: TS
authors: Barry
authors: Shelly
authors: S
authors: Gunn
authors: Wayne
authors: W
authors: Tam
authors: Attilio
authors: A
authors: Orazi
authors: Young S
authors: YS
authors: Kim
authors: Lawrence M
authors: LM
authors: Weiss
mesh_terms: D055028:Comparative Genomic Hybridization; D054739:Dendritic Cell Sarcoma, Interdigitating / Q000235:genetics* / Q000473:pathology*; D006646:Histiocytosis, Langerhans-Cell / Q000235:genetics* / Q000473:pathology*; D006801:Humans
keywords: Array comparative genomic hybridization; Genetics; Interdigitating dendritic cell sarcoma; Langerhans cell histiocytosis