Kimura's disease and angiolymphoid hyperplasia with eosinophilia: new observations from immunohistochemical studies of lymphocyte markers, endothelial antigens, and granulocyte proteins.

Kimura's disease (KD) typically presents as large subcutaneous masses in young Oriental males. It is characterized by deep inflammation with vascular proliferation, lymphocytic nodules with subcutaneous germinal centers, fibrosis, and edema. In comparison, angiolymphoid hyperplasia with eosinophilia (AHLE) occurs in all races and the lesions usually are smaller and more superficial. The causes of these two diseases are debated. We compared histologic features of 4 cases of KD with 22 cases of ALHE and studied expression of endothelial antigens and lymphocyte markers as well as localization of eosinophil, mast cell, and neutrophil granule proteins in lesional tissue. T-cell lymphoid aggregates with well-formed B-cell germinal centers occurred in KD, and nodular and diffuse T-cell infiltration with small B-cell clusters occurred in ALHE. Endothelial proliferation was more pronounced in KD, lacking the atypical histiocytoid endothelial cells characteristic of ALHE. Many intact eosinophils infiltrated lesions in both diseases, although KD had less extracellular granule protein deposition than ALHE. Intact mast cells were seen in both diseases. There was neutrophil elastase staining of occasional scattered intact cells but no extracellular deposition. Compared with KD, ALHE is more varied in its clinical, histopathologic, and immunohistochemical features.