Interdigitating Dendritic Cell Sarcoma



Interdigitating Dendritic Cell Sarcoma


Wesley O. Greaves, MD

L. Jeffrey Medeiros, MD










Interdigitating dendritic cell sarcoma subtotally replacing lymph node. The neoplasm tends to spare lymphoid follicles. The neoplasm was S100 protein(+).






Interdigitating dendritic cell sarcoma involving lymph node. The neoplastic cells are spindled and epithelioid with abundant eosinophilic cytoplasm. A mitotic figure is present image.


TERMINOLOGY


Abbreviations



  • Interdigitating dendritic cell (IDC) sarcoma


Synonyms



  • Interdigitating cell dendritic cell tumor


  • Interdigitating dendritic reticulum cell sarcoma


Definitions



  • Neoplastic proliferation of cells with immunophenotypic profile that is similar to normal IDCs


ETIOLOGY/PATHOGENESIS


Postulated Normal Cell Counterpart is IDC



  • Antigen-presenting cell that is involved in T-cell immunity


  • Derived from CD34(+) lymphoid/myeloid progenitor cell in bone marrow that homes to lymph node


  • Normally found in



    • T-cell regions of lymph node


    • Periarteriolar lymphoid sheaths


    • Interfollicular areas of extranodal lymphoid tissue


Concept of “Transdifferentiation”



  • Rare patients with histiocytic neoplasms also have clonally related B-cell lymphoma



    • Usually B-cell lymphoma precedes histiocytic neoplasm


    • Examples in literature include



      • IDC sarcoma and follicular lymphoma


      • Histiocytic sarcoma and follicular lymphoma


      • IDC sarcoma and chronic lymphocytic leukemia/small lymphocytic lymphoma


      • Histiocytic sarcoma and splenic marginal zone lymphoma


    • Histiocytic neoplasms associated with follicular lymphoma share



      • t(14;18)(q32;q21)/BCL2-IgH &/or identical IgH gene rearrangements


    • Histiocytic tumors and nonfollicular B-cell lymphomas share identical IgH gene rearrangements


  • These results suggest that B-cell lymphoma can transform to histiocytic phenotype via “transdifferentiation”



    • Possibly as result of loss of key components of B-cell differentiation


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Very rare


  • Age



    • Wide age range



      • Most patients are adults with median age in 6th or 7th decades


      • Youngest patient reported was 2 years of age


  • Gender



    • Male to female ratio: 1.2 to 1


Site



  • Lymph node



    • Most commonly a single lymph node is involved


    • Cervical, axillary, or inguinal lymph node groups most often affected


  • Extranodal sites can be involved



    • Wide variety of extranodal sites



      • Skin and soft tissue most common


      • Liver and spleen


      • Gastrointestinal tract, lung, kidney


    • Bone marrow is involved in < 20% of patients


Presentation



  • Slow-growing, asymptomatic mass is most common



  • Systemic symptoms occur in subset of patients



    • Fever, night sweats, fatigue


  • Small subset of patients have IDC sarcoma and another hematopoietic neoplasm including



    • Chronic lymphocytic leukemia/small lymphocytic lymphoma


    • Mycosis fungoides


    • Acute lymphoblastic leukemia (mostly of T-cell lineage)


  • Small subset of patients with IDC sarcoma also have carcinoma



    • Most common types: Breast, stomach, liver, colon


Treatment



  • Surgical resection and radiation therapy for patients with localized disease


  • Currently, there is no established chemotherapy regimen



    • ABVD (doxorubicin, bleomycin, vincristine, and dacarbazine) and other regimens have been used



      • Many patients initially respond but relapse, and death is common in this patient subset

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Interdigitating Dendritic Cell Sarcoma
Premium Wordpress Themes by UFO Themes
%d bloggers like this: