Pituitary gland abscess in a horse subsequent to head trauma

Abstract

Summary A 5‐year‐old Thoroughbred gelding with recent history of head trauma presented with multiple facial swellings, bilateral mucopurulent nasal discharge, neck pain, inappetence and depression. On computed tomographic examination, lesions within the pituitary fossa and structures adjacent to the right guttural pouch were identified. Soft tissue swelling was seen in the dorsal aspect of the right guttural pouch surrounding several cranial nerves, with fluid‐like material in the dependent portions of the right guttural pouch. A CSF sample revealed mild mixed pleocytosis and increased protein concentration. The horse had concurrent periapical disease of the 209‐cheek tooth and mild left sinusitis. The horse's demeanour deteriorated requiring euthanasia. Post‐mortem examination revealed a pituitary gland abscess.

CT diagnosis of pituitary abscess, suppurative meningitis, and atlanto‐occipital septic arthritis in a pony

“…The concomitant presence of a tooth fracture and secondary sinusitis is interesting, as dental disorders have been previously observed in horses with pituitary abscess, 4,6 and as sinusitis has been reported in affected humans 10 . This case also had necropsic evidence of basisphenoid osteomyelitis.…”

“…Skull base suppurative processes and AOJ septic arthritis are overall rare conditions, which have been sporadically and separately described in the equine species 2–6 . In the absence of direct penetration, infectious conditions of the central nervous system in horses can result from a systemic disorder or from local extension of an infectious disease 7 .…”

“…In humans, hematogenous intracranial septic dissemination has been reported, either originating from the paranasal sinuses, or from the oropharynx 8–10 . The pituitary gland appears to be a preferential location for brain abscessation 4–6 . In human medicine, necrobacillosis resulting from metastatic dissemination from an oropharyngeal infection is known as the Lemierre syndrome when recent oropharyngeal illness is combined with evidence of metastatic disease and either evidence of thrombophlebitis of the internal jugular vein or pathogen detection (most commonly Fusobacterium necrophorum or Fusobacterium sp .)…”

“…Macroadenoma is a reported risk factor in human medicine for pituitary abscessation, 11,12 and was described as a valuable differential for pituitary abscess in a recent equine case report 4 . Given the cavitary appearance of the lesion, the lack of known history and clinical signs of pituitary pars intermedia dysfunction and the postmortem confirmation, the authors considered a macroadenoma or a subclinical pituitary adenoma as an unlikely differential diagnosis.…”

“…Skull base suppurative processes and AOJ septic arthritis are overall rare conditions, which have been sporadically and separately described in the equine species. [2][3][4][5][6] In the absence of direct penetration, infectious conditions of the central nervous system in horses can result from Various infectious processes involving the head have been implicated, such as sinusitis, rhinitis, (peri)ocular infection and lymphadenopathy. 6 In these cases, the authors hypothesized that the retrograde blood flow to the brain could be the route of dissemination to the meninges, via thrombo-embolic processes.…”