Angiolymphoid hyperplasia with eosinophilia involving skeletal muscle.

A vascular tumour involving the trapezius muscle is described. In addition to proliferating blood vessels with perithelial cuffing, there was a distinctive stroma of lymphoid aggregates, plasmacytoid cells, some mast cells and large numbers of eosinophils, many with a perivascular distribution. This solely intramuscular lesion was considered to be an example of angiolymphoid hyperplasia with eosinophilia. The aetiology and pathogenesis are discussed.