An Unusual Case of Generalized Ceroid-Lipofuscinosis in a Cynomolgus Monkey

Abstract

Histologic, histochemical, and electron microscopic studies of generalized ceroid-lipofuscinosis in a cynomolgus monkey are presented. Histologically, a wide variety of tissue cells contained numerous bright eosinophilic intracytoplasmic granules that varied in size from 0.5 μm to 4.0 μm in diameter. Histochemically, the granules gave a weakly positive reaction with periodic acid-Schiff and for lipids. They were weakly acid fast and capable of emitting autofluorescence. Ultrastructurally, the granules were single unit membrane-bound, and contained dense osmiophilic material with frequent concentric or fingerprint-type lamellar formation. The granules were different than hemofuscin, iron, and bilirubin. Tinctorially the granules were unique—they were bright red with hematoxylin and eosin and, thus, differed from typical age-related lipofuscin pigment.