Felis ISSN 2398-2950

Pituitary gland: neoplasia

Synonym(s): Pituitary adenoma, pituitary macroadenoma

Contributor(s): Laura Garrett, Philip K Nicholls


  • Intracranial neoplasms are rare in cats (3.5/100,000), and pituitary tumors are the third most common intracranial neoplasm, making up less than 10% of such neoplasms, with meningioma Meningioma  most common and lymphoma Lymphoma second most common. 
  • Pituitary tumors in cats are more likely to be functional than similar tumors in dogs, and presenting signs may relate to endocrine disease.



  • No known specific carcinogenic risk factors spontaneous neoplasia.


  • If acromegaly Acromegaly is present, it is usually due to a functional adenoma of the pars distalis adenohypophysis.
  • Pituitary tumors may be functional, with signs arising from both space-occupying lesion effects, and effects due to tumor products, OR tumor may be non-functional, with effects arising primarily from the space-occupying lesion.
  • Functional chromophobe (corticotroph) adenomas of pars distalis may secrete excess ACTH autonomously, causing hyperadrenocorticism Hyperadrenocorticism.
  • Non-functional chromophobe adenomas reported also, with signs related to local extension and compression of optic nerves and other structures.
  • Functional acidophil adenomas of par distalis secrete excess growth hormone (x30-x100 normal serum levels), with associated acromegaly Acromegaly and insulin-resistant diabetes mellitus Diabetes mellitus.
  • Tumors may arise from pars intermedia also, with associated raised serum alpha-MSH (melanocyte stimulating hormone)


  • Timecourse reflects neoplastic growth (space-occupying effects) and/or function (hormonal effects), over weeks to months.


  • Typically isolated, spontaneous neoplasms.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Brearley M J & Polton G A (2005) Coarse fractionated radiation therapy for pituitary tumors in cats: a retrospective study of 10 cases. Vet Comp Oncol (1), 38-39 Wiley Online Library.
  • Meij B P, van der Vlugt-Meijer R H, van den Ingh T S et al (2004) Somatotroph and corticotroph pituitary adenoma (double adenoma) in a cat with diabetes mellitus and hyperadrenocorticism. J Comp Pathol 130 (2-3), 209-215 PubMed.
  • Neiger R, Witt A L, Noble A et al (2004) Trilostane therapy for treatment of pituitary-dependant hyperadrenocorticism in 5 cats. J Vet Intern Med 18 (2), 160-164 PubMed.
  • Troxel M T, Vite C H, Massicotte C et al (2004) Magnetic resonance imaging features of feline intracranial neoplasia: retrospective analysis of 46 cats. J Vet Intern Med 18 (2), 176-189 PubMed.
  • Skelly B J, Petrus D, & Nicholls P K (2003) Use of trilostane for the treatment of pituitary-dependant hyperadernocorticism in a cat. J Small Anim Pract 44 (6), 269-272 PubMed.
  • Troxel M T, Vite C H, Van Winkle T J et al (2003) Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001). J Vet Intern Med 17 (6), 850-859 PubMed.
  • Kaser-Hotz B, Rohrer C R, Stankeova S et al (2002) Radiotherapy of pituitary tumours in five cats. J Small Anim Pract 43 (7), 303-307 PubMed.
  • Meij B P, Voorhout G, Van Den Ingh T S et al (2001) Transsphenoidal hypophysectomy for treatment of pituitary-dependent hyperadrenocorticism in 7 cats. Vet Surg 30 (1), 72-86 PubMed.
  • Elliott D A, Feldman  E C, Koblik P D et al (2000) Prevalence of pituitary tumors among diabetic cats with insulin resistance. J Am Vet Med Assoc 216 (11), 1765-1768 PubMed.
  • Goossens M M, Feldman E C, Nelson R W et al (1998) Cobalt 60 irradiation of pituitary gland tumors in three cats with acromegaly. J Am Vet Med Assoc 213 (3), 374-376 PubMed.
  • Schwedes C S (1997) Mitotane (o,p-DDD) treatment in a cat with hyperadrenocorticism. J Small Anim Pract 38 (11), 520-524 PubMed.
  • Lichtensteiger C A, Wortman J A & Eigenmann J E (1986) Functional pituitary acidophilic adenoma in a cat with diabetes and acromegalic features. Vet Pathol 23 (4), 518-521 PubMed.
  • Eigenmann J E, Wortman J A & Haskins M E (1984) Elevated growth hormone levels and diabetes mellitus in a cat with acromegalic features. J Am Anim Hosp Assoc 20 (5), 747-752 VetMedResource.
  • Zaki F A & Liu S K (1973) Pituitary chromophobe adenoma in a cat. Vet Pathol 10 (3), 232-237 PubMed.

Other sources of information

  • Capen C C (2002) Tumors of the Endocrine Glands. In: Meuten D J (ed)Tumors in Domestic Animals. 4th edn. Ch 13 pp 607-696. Iowa State Press.
  • Withrow and MacEwen (2001) Small Animal Clinical Oncology. 3rd edn. Saunders.