Presumed pituitary apoplexy in 26 dogs: Clinical findings, treatments, and outcomes

Abstract

Background: Pituitary apoplexy refers to hemorrhage or infarction within the pituitary gland resulting in acute neurological abnormalities. This condition is poorly described in dogs.

Objectives: To document presenting complaints, examination findings, endocrinopathies, magnetic resonance imaging (MRI), treatments, and outcomes of dogs with pituitary apoplexy.

Animals: Twenty-six client-owned dogs with acute onset of neurological dysfunction.

Methods: Retrospective case series. Dogs were diagnosed with pituitary apoplexy if MRI or histopathology documented an intrasellar or suprasellar mass with evidence of hemorrhage or infarction in conjunction with acute neurological dysfunction. Clinical information was obtained from medical records and imaging reports.

Results: Common presenting complaints included altered mentation (16/26, 62%) and gastrointestinal dysfunction (14/26, 54%). Gait or posture changes (22/26, 85%), mentation changes (18/26, 69%), cranial neuropathies (17/26, 65%), cervical or head hyperpathia (12/26, 46%), and hyperthermia (8/26, 31%) were the most frequent exam findings. Ten dogs (38%) lacked evidence of an endocrinopathy before presentation. Common MRI findings included T1-weighted hypo- to isointensity of the hemorrhagic lesion (21/25, 84%), peripheral enhancement of the pituitary mass lesion (15/25, 60%), brain herniation (14/25, 56%), and obstructive hydrocephalus (13/25, 52%). Fifteen dogs (58%) survived to hospital discharge. Seven of these dogs received medical management alone (median survival 143 days; range, 7-641 days) and 8 received medications and radiation therapy (median survival 973 days; range, 41-1719 days).

Conclusions and clinical importance: Dogs with pituitary apoplexy present with a variety of acute signs of neurological disease and inconsistent endocrine dysfunction. Dogs that survive to discharge can have a favorable outcome.

Keywords: adenoma; carcinoma; endocrionopathy; hemorrhage; magnetic resonance imaging; suprasellar; survival.

FIGURE 1

Magnetic resonance imaging of pituitary apoplexy in the same dog. (A) Transverse susceptibility‐weighted imaging (SWI) reveals a large suprasellar blooming artifact (marked with white asterisk). (B) Transverse T2‐weighted (T2W) image revealing an ovoid suprasellar mass which is heterogeneously T2 hypointense with internal T2 hyperintense foci relative to surrounding gray matter. Obstructive hydrocephalus of the left lateral ventricle is marked with the black arrow, with deviation of the septum pellucidum (black arrowhead), consistent with a falcine shift. (C) Transverse T1‐weighted (T1W) image heterogeneously T1 hypointense with internal T1 hyperintense foci relative to surrounding gray matter. (D‐F) Respectively, transverse, sagittal, and dorsal T1W images after contrast administration, showing strong contrast‐enhancement with some areas of ring‐enhancement (white arrows). There is flattening of the rostral cerebellum and compression of the rostral colliculi, consistent with transtentorial herniation.

FIGURE 2

Survival curves for (A) the entire cohort of dogs with pituitary apoplexy and (B) those dogs that survived to hospital discharge. Dogs that received radiation therapy in addition to medical therapy (solid line) survived longer than those receiving medical therapy alone (dashed line, P = .008). Ticks represent dogs that were censored during analysis.