Three unusual histopathological presentations of angiolymphoid hyperplasia with eosinophilia.

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a poorly understood benign vasculoproliferative disorder. Histopathologically, the lesions are composed of a dermal or subcutaneous proliferation of blood vessels of varying sizes with plump and bland endothelial cells, which often show vacuolization and protrusion of the cytoplasm into the lumen. The vascular proliferation is admixed with a diffuse inflammatory infiltrate composed of lymphocytes, eosinophils and mast cells. Lymphoid follicles with germinal centers can sometimes be seen. In addition, fibrosis is a common accompanying feature. Some clinical and histopathological variants of ALHE have already been described in the literature. In this report, we present 3 rare associations of ALHE that have not been previously described. Case 1 was a 73-year-old woman with a lesion on her right medial thigh. Examination showed ALHE admixed with a chronic lymphocytic leukemic (CLL) infiltrate. Case 2 was a 55-year-old woman with a lesion on her right anterior ankle, which was a syringocystadenoma papilliferum co-existing with an ALHE. Case 3 was a 54-year-old man with a lesion on the left medial thigh, which showed overlapping features of IgG4-related disease associated with areas of ALHE. Given these multiple and diverse associations, it seems likely that ALHE may be a reactive rather than neoplastic process.