title: Langerhans cell sarcoma in a patient with hairy cell leukemia: common clonal origin indicated by identical immunoglobulin gene rearrangements.
abstract: Histiocytic/dendritic cell sarcomas are rare tumors, a few of which have been reported in association with B-cell lymphoma/leukemia. Isolated reports have documented identical immunoglobulin gene rearrangements suggesting a common clonal origin for both the sarcoma and the B-cell neoplasm from individual patients. We report a case of a 75-year-old male with hairy cell leukemia who subsequently developed Langerhans cell sarcoma 1 year after his primary diagnosis of leukemia. The bone marrow biopsy containing hairy cell leukemia and skin biopsies of Langerhans cell sarcoma were evaluated by routine histology, immunohistochemistry, flow cytometric immunophenotyping and PCR-based gene rearrangement studies of the immunoglobulin heavy chain and kappa genes. The hairy cell leukemia showed characteristic morphologic, immunohistochemical and flow cytometric features. The Langerhans cell sarcoma showed pleomorphic cytology, a high mitotic rate and characteristic immunohistochemical staining for Langerin, S100 and CD1a. There was no evidence of B-cell differentiation or a background B-cell infiltrate based on the absence of immunoreactivity with antibodies to multiple B-cell markers. Identical immunoglobulin gene rearrangements were identified in both the hairy cell leukemia and Langerhans cell sarcoma specimens. Despite the phenotypic dissimilarity of the two neoplasms, identical immunoglobulin gene rearrangements indicate a common origin.
authors.affiliation: Department of Pathology, University of Washington Medical Center, 1959 NE Pacific, Seattle, WA 98195-6100, USA. pfurmanczyk@gmail.com
authors.forename: Paul S
authors.initials: PS
authors.lastname: Furmanczyk
authors.forename: Allison E
authors.initials: AE
authors.lastname: Lisle
authors.forename: Russell B
authors.initials: RB
authors.lastname: Caldwell
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Kraemer
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Mercer
authors.forename: Evan
authors.initials: E
authors.lastname: George
authors.forename: Zsolt B
authors.initials: ZB
authors.lastname: Argenyi
mesh_terms: D000368:Aged; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics; D001853:Bone Marrow; D002454:Cell Differentiation / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D054752:Langerhans Cell Sarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007943:Leukemia, Hairy Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D016609:Neoplasms, Second Primary / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D027041:Somatic Hypermutation, Immunoglobulin / Q000235:genetics*; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins