title: Granular cell tumour in an endangered Puerto Rican Amazon parrot (Amazon vittata ).
abstract: A 3 cm diameter mass from the metacarpus of a Puerto Rican Amazon parrot was diagnosed as a granular cell tumour based on light microscopy. The cytoplasmic granules were periodic-acid Schiff positive and diastase resistant. Ultrastructural characteristics of the cells included convoluted nuclei and the presence of numerous cytoplasmic tertiary lysosomes. This is only the second granular cell tumour reported in a bird. We speculate that most granular cell tumours are derived from cells that are engaged in some type of cellular degradative process, creating a similar morphologic appearance, but lacking a uniform histogenesis.
authors.forename: C F
authors.initials: CF
authors.lastname: Quist
authors.forename: K S
authors.initials: KS
authors.lastname: Latimer
authors.forename: S L
authors.initials: SL
authors.lastname: Goldade
authors.forename: A
authors.initials: A
authors.lastname: Rivera
authors.forename: F J
authors.initials: FJ
authors.lastname: Dein