title: Granuloma annulare-like eruption associated with B-cell chronic lymphocytic leukemia.
abstract: BACKGROUND
  Cutaneous granulomatous inflammation can occur in patients with T-cell lymphoma and Hodgkin disease. We describe the unusual microscopic pattern of a granuloma annulare (GA)-like eruption co-existing with B-cell chronic lymphocytic leukemia (B-CLL).
  
  
  METHODS
  We reviewed the histopathology and immunophenotype of skin biopsies from two patients with B-CLL and cutaneous lesions resembling GA.
  
  
  RESULTS
  Both patients had symptomatic cutaneous lesions clinically resembling GA; one had lesions refractory to standard dermatologic therapy. Histopathology showed GA-like palisaded histiocytic infiltration, with subtle collections of lymphocytes interspersed among the granulomatous inflammation. Immunohistochemistry showed strong expression of CD20 and CD79a, with aberrant CD5 co-expression, confirming cutaneous involvement by B-CLL.
  
  
  CONCLUSIONS
  Co-existence of a GA-like infiltrate and cutaneous B-CLL raises the possibility that granulomatous inflammation occurs as a secondary response to dermal infiltration by leukemic cells. Because histopathologic findings can be subtle, knowledge of this association is essential to avoid overlooking the diagnosis. Regardless of whether histopathology reflects a reactive or primary phenomenon, documentation of cutaneous involvement by B-CLL may serve as a rationale for specific treatment of the underlying B-CLL in patients with skin lesions unresponsive to dermatologic therapy and for whom there is no other justification for leukemia-targeted therapy.
authors: Department of Dermatology, Mayo Clinic, Rochester, MN 55905, USA.
authors: Olayemi
authors: O
authors: Sokumbi
authors: Lawrence E
authors: LE
authors: Gibson
authors: Nneka I
authors: NI
authors: Comfere
authors: Margot S
authors: MS
authors: Peters
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000096:biosynthesis*; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D016460:Granuloma Annulare / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism / Q000473:pathology; D008297:Male; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology
chemical_list: D015703:Antigens, CD; D009363:Neoplasm Proteins