[1317] Coexistence of Langerhans Cell Histiocytosis and Rosai-Dorfman Disease: Related-Disorders?

A Duong, DP O'Malley, TS Barry, S Chen, JA Ferry, RP Hasserjian, MA Thompson, MS Richardson, R Jaffe, JS Sidhu, PM Banks. Medical University of South Carolina, Charleston, SC; Clarient Inc, Aliso Viejo, CA; Massachusetts General Hospital, Boston, MA; Vanderbilt, Nashville, TN; Children's Hospital of Pittsburgh, Pittsburgh, PA; UHS Hospitals, Binghamton, NY; Carolinas Medical Center, Charlotte, NC

Background: Rosai-Dorfman disease (RDD) and Langerhans cell histiocytosis (LCH) are disorders of accessory cells. LCH is a clonal proliferation of LC. In contrast, RDD is a non-neoplastic proliferation of unusual histiocytes with emperipolesis and S100 expression. In the literature, two cases have been reported of concurrent LCH and RDD. In this report, we characterize the pathologic and clinical findings, as well as selected molecular studies, in 9 additional cases.
Design: Cases were obtained from several institutions with attention to local guidelines for research. Clinical information, histology and submitted immunohistochemical (IHC) stains were reviewed. IHC was performed on all cases where slides or blocks were available. Depending on the materials, a combination of CD1a, S-100, CD3, CD20, langerin, CD68, CD163, CD21, CD35, CD123, vimentin, in situ EBV (EBER) and AE1/AE3 IHC stains were performed. High resolution array comparative genomic hybridization (aCGH) was performed on Case 1, with additional cases pending.
Results: 7 were female and 2 male, with an average age of 25 (15 mos.- 59 yrs.). Sites varied, although most cases (89%) were lymph node. LCH had typical appearance with eosinophils. The immunophenotype showed CD1a, S100, CD68, CD163, and langerin. In areas of RDD, emperipolesis was seen in all cases. Cells were small and round with ample pale cytoplasm. RDD areas were positive for S100, CD68, CD163, without expression of langerin or CD1a. aCGH showed a deletion in 16p in Case 1; other cases are pending.
Conclusions: We report findings of exceedingly rare combination of LCH and RDD. Our cases illustrate that these tumors do indeed coexist and that it is possible that their (co-)incidence may be less rare than previously reported. Based on evidence from our cases, when simultaneous, these two entities may be pathophysiologically related. Additional molecular testing (aCGH) is pending on cases at this time.
Category: Hematopathology

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 219, Tuesday Morning


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