Spontaneous rupture of a secondary pituitary abscess causing acute meningoencephalitis: Case report and literature review

Abstract

Background: Pituitary abscess (PA) is an uncommon finding that is rarely diagnosed preoperatively. If not properly treated it is associated with high morbidity and mortality rates. Nowadays standard diagnostic procedures allow early detection and successful treatment of this lesion in a high number of cases and mortality has been significantly reduced in recent years. PA arising de novo in a healthy gland are defined as primary, whereas those complicating a pre-existing disease of the hypophysis are called secondary abscesses.

Case description: We present a case of a secondary PA mimicking a large pituitary adenoma extending in the nasal cavity, which was wrongly diagnosed as such. The abscess showed an unexpected evolution in 48 h from presentation due to a sudden, extensive intracranial leakage of pus.

Conclusions: To our knowledge, it is rare to find PA showing a rapid evolution like this, and in the literature only one previous case of a PA not reaching medical or surgical therapy was reported. In that case, hypothalamus involvement was identified as the cause of death. This should be the first case reported of a spontaneous PA rupture causing acute meningoencephalitis. Along with a short review of the literature on the major features of PA, we also tried to identify some features which could be supportive of a diagnosis of secondary PA.

Keywords: Adenoma; brain abscess; meningoencephalitis; pituitary abscess; pituitary neoplasm.

Figure 1

(a) Pre-operative magnetic resonance imaging (MRI) with gadolinium. T1-weighted coronal section showing a large enhancing sellar lesion with suprasellar extension, impinging the chiasm and abutting both cavernous sinuses. (b) T1-weighted sagittal section with gadolinium showing a mixed solid-cystic component of the tumor. The chiasm is dislocated upwards (c) T2-weighted coronal scan showing a mixed solid-cystic components of the lesion

Figure 2

(a and b) CT scan performed after sudden clinical deterioration showed no clear intra- or extr-axial bleeding or fluid collection. No ischemia could be detected. (c) The lesion of the sella had eroded the skull base

Figure 3

(a and b) Intra-operative pictures, right fronto-temporal craniotomy: The brain was swelling, with evident pus in the sulci and on the brain surface

Figure 4

Intra-operative picture: Inside the sellar lesion, more pus was found and drained

Figure 5

(a) Haematoxilin-eosin stained section of the adenoma at 4x magnification showing neoplastic cells admixed with a robust inflammatory infiltrate with neutrophils. (b) The same section at 10× magnification. (c) Synaptophysin positive immunostained section(4×)