Cutaneous manifestations of angioimmunoblastic lymphadenopathy.

Six of 22 patients with angioimmunoblastic lymphadenopathy seen at the Mayo Clinic from 1962 to 1978 had associated cutaneous lesions exhibiting characteristic histologic features at biopsy. Clinically, three patients had generalized maculopapular eruptions, two had generalized petechiae, and one had generalized erythroderma and petechiae located on the extremities. In each patient, the eruption occurred concurrent with or prior to the onset of generalized lymphadenopathy. Pathologically, all skin biopsy specimens showed lymphohistiocytic vasculitis, vascular proliferation, extravasated RBCs, and occasional scattered mature plasma cells. These histologic findings were similar to but less intensive than those noted on biopsy specimens of involved lymph nodes. Although suggestive of angioimmunoblastic lymphadenopathy, the histologic findings of skin lesions do not appear to be diagnostic, thus stressing the difficulty of defining the syndrome in the absence of lymph node biopsy.