Calcinosis circumscripta of the tongue in a cat.

A nodular mass present on the ventral surface of the tongue in a mature, castrated male domestic short-haired cat was diagnosed as calcinosis circumscripta. The cat died of end-stage renal disease. Histologically, the multilobulated mass was composed of acellular, fractured loculi separated by thin bands of a connective tissue stroma. Loculi contained a light red crystalline substance, surrounded by amorphous basophilic mineralized material. No specific relationship is suggested between the end-stage renal disease and the tongue lesion.