Lymphocytic hypophysitis in a dog with diabetes insipidus.
An 8-year-old male German longhaired pointer was referred for diabetes insipidus responsive to treatment with desmopressin. The dog had polyuria and polydipsia, exercise intolerance and a dull hair coat. Plasma concentrations of thyroid-stimulating hormone, thyroxine, growth hormone (GH) and insulin-like growth factor-1 were decreased; plasma adrenocorticotropic hormone (ACTH) was slightly elevated and plasma α-melanocyte-stimulating hormone (MSH) was within the reference range. Computed tomography revealed a heterogeneously contrast-enhancing pituitary mass compressing the hypothalamus. Transsphenoidal hypophysectomy was performed and microscopical examination of the surgical biopsy samples revealed hypophysitis without evidence of pituitary adenoma. The hypophysitis was characterized by marked lymphocytic infiltration of the adenohypophysis that contained a mixed population of neuroendocrine cells expressing GH, ACTH or α-MSH. The lymphocytes were identified as T cells, resulting in a final diagnosis of lymphocytic hypophysitis strongly resembling human primary lymphocytic hypophysitis.
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 110, 3508 TD Utrecht, The Netherlands. b.p.meij@uu.nl
B P
BP
Meij
G
G
Voorhout
R J
RJ
Gerritsen
G C M
GC
Grinwis
J
J
Ijzer
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D050034:Antidiuretic Agents / Q000627:therapeutic use; D003894:Deamino Arginine Vasopressin / Q000627:therapeutic use; D003919:Diabetes Insipidus / Q000473:pathology / Q000628:therapy / Q000662:veterinary*; D004283:Dog Diseases; D004285:Dogs; D037901:Euthanasia, Animal; D017809:Fatal Outcome; D013006:Growth Hormone / Q000378:metabolism; D007018:Hypopituitarism / Q000378:metabolism / Q000473:pathology / Q000628:therapy / Q000662:veterinary*; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D055099:Neuroendocrine Cells / Q000378:metabolism / Q000473:pathology; D010903:Pituitary Gland, Anterior / Q000378:metabolism / Q000473:pathology*; D000521:alpha-MSH / Q000378:metabolism
D050034:Antidiuretic Agents; D000521:alpha-MSH; D000324:Adrenocorticotropic Hormone; D013006:Growth Hormone; D003894:Deamino Arginine Vasopressin