Tumors of the endocrine system in the horse - clinical pathology

Endocrine tumours in equids

“…Despite pituitary tumours being more common in aged horses, recent improvements in PPID testing has allowed earlier diagnosis in younger animals (Ellenberger et al . ). Sex and breed do not appear to influence PPID incidence.…”

“…), with carcinomas being infrequent (Ellenberger et al . ). Rarely, corticotrope neoplasms originated from corticotroph ( pars distalis ) have been documented in horses (Kiupel et al .…”

“…Adrenal cortical tumours are markedly rare, with only scarce reports of adenomas causing hyperhidrosis, lethargy, increased appetite, muscle wasting and delayed coat shedding, and carcinomas with colic signs due to rupture and formation of an intra‐abdominal haematoma (Ellenberger et al . ) as well as metastases to adjacent and distant organs. There is no known breed or sex predisposition.…”

“…; Ellenberger et al . ), or C‐cell adenoma, pheochromocytoma and pituitary adenoma (Monahan and Craig ). Moreover, cases of MEN‐like cases showing concomitant nonendocrine tumours (as observed in man) have also been described in horses, such as concomitant C‐cell carcinoma, thyroid follicular adenomas and a duodenal adenocarcinoma (Dittus et al .…”

“…The pituitary, thyroid and adrenal glands are the most commonly affected locations for these neoplasms (Ellenberger et al . ). Most tumours comprise a single type of specialised secreting cell, although neoplasms able to synthesise and secrete different polypeptide hormones have been documented (O'Brien et al .…”