Pituitary abscess

Last revised by Daniel J Bell on 13 Jun 2022

Citation, DOI, disclosures and article data

Citation:

Gaillard F, Bell D, Hacking C, Pituitary abscess. Reference article, Radiopaedia.org (Accessed on 25 Apr 2024) https://doi.org/10.53347/rID-59666

DOI:

https://doi.org/10.53347/rID-59666

Permalink:

https://radiopaedia.org/articles/59666

rID:

59666

Article created:

19 Apr 2018, Frank Gaillard ◉ ◈

Disclosures:

At the time the article was created Frank Gaillard had no recorded disclosures.

View Frank Gaillard's current disclosures

Last revised:

13 Jun 2022, Daniel J Bell ◉

Disclosures:

At the time the article was last revised Daniel J Bell had no financial relationships to ineligible companies to disclose.

View Daniel J Bell's current disclosures

Revisions:

3 times, by 3 contributors - see full revision history and disclosures

Systems:

Central Nervous System

Synonyms:

Pituitary abscesses
Pituitary gland abscesses
Pituitary gland abscess

Pituitary abscesses are rare and represent infection of the pituitary gland by organisms, most commonly bacteria.

Often, the presentation is relatively indolent without overt features of infection ¹. Symptoms include those from mass effect (e.g. bitemporal hemianopia and headaches), endocrinological dysfunction (e.g. loss of libido, polydipsia, polyuria, amenorrhoea) and only sometimes (~25%) infective symptoms (e.g. fevers and meningism) ^1,2. As such pituitary abscesses are often not diagnosed pre-operatively but rather are thought to be the far more common pituitary adenoma that not infrequently demonstrate cystic/necrotic degenerative change.

Pathology

As is the case with many other infections, the route of infection is varied and can be haematogenous, extension from an adjacent infection (e.g. sphenoid sinusitis) or direct inoculation after surgery ¹.

In the majority of cases (70%) the underlying pituitary is normal prior to infection ^1,3. These are sometimes referred to a 'primary' pituitary abscess. In contrast, 'secondary' pituitary abscesses are those that arise in a previously abnormal pituitary (e.g. existing tumour) ³.

Microbiology

A wide variety of pathogens have been isolated from pituitary abscesses, including ¹:

bacteria
- Staphylococcus spp and Streptococcus spp (most common)
- Neisseria spp., Citrobacter spp., E. coli, Brucella, Salmonella etc...
mycobacterium
fungus (most common in immunosuppressed patients)
- Aspergillus, Candida and Histoplasma

Radiographic features

CT

CT of the brain and base of the skull may demonstrate a low central attenuating mass. With the administration of contrast, vivid peripheral contrast enhancement is usually present.

Thin bone reformats usually do not demonstrate significant enlargement of the sella as the lesion has only been present for a relatively short time, however, erosion of bone may be seen as may evidence of adjacent infection.

MRI

MRI is the modality of choice for evaluating a patient suspected of having a pituitary abscess. It will demonstrate features of an abscess; peripherally enhancing mass with central high T2 signal, high DWI signal and low ADC values. It should be noted, however, that macroadenomas with haemorrhagic change may have similar appearances.

Treatment and prognosis

Treatment is surgical with transsphenoidal hypophysectomy, drainage, and antibiotics ^1-3. Pituitary function often does not recover and long-term hormone replacement is necessary ^1,2.