title: Somatotroph pituitary tumors in budgerigars (Melopsittacus undulatus).
abstract: A series of 11 pituitary tumors in budgerigars were classified on the basis of their clinical, gross, microscopic, and immunohistochemical characteristics. Affected birds were young to middle-aged. Clinically, neurologic signs--including difficulties flying, ataxia, and blindness--were most commonly reported. Additional clinical signs included weight loss, abnormal feathers or molting, increased respiratory efforts, and exophthalmos. Nine birds were diagnosed with chromophobic pituitary adenomas, and 2 birds had chromophobic pituitary carcinomas. Only 1 tumor was delimited to the pituitary gland; the other 10 variably invaded the brain, skull, and retrobulbar space. Distant metastases were identified in 2 birds. All tumors were immunohistochemically strongly positive for growth hormone, consistent with the diagnosis of somatotroph tumors. The common occurrence and early onset may suggest a genetic predisposition of budgerigars to develop somatotroph pituitary tumors with a high incidence of local invasion and with metastatic potential.
authors: Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA. langohri@dcpah.msu.edu
authors: I M
authors: IM
authors: Langohr
authors: M M
authors: MM
authors: Garner
authors: M
authors: M
authors: Kiupel
mesh_terms: D000238:Adenoma, Chromophobe / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D000836:Animals, Zoo; D001715:Bird Diseases / Q000473:pathology*; D017809:Fatal Outcome; D007150:Immunohistochemistry / Q000662:veterinary; D046408:Melopsittacus; D010907:Pituitary Hormones / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000473:pathology / Q000662:veterinary*
chemical_list: D010907:Pituitary Hormones