Two rare cases of Pituitary abscess reported

Dr Yaotse Elikplim Nordjoe at Radiology Department, Centre Hospitalo-Universiataire Ibn Sina, Rabat, Morocco and colleagues have reported two rare cases of Pituitary abscess.The case has appeared in the Journal of Medical Case Reports.

A pituitary abscess is a rare condition with nonspecific symptoms that can be delayed. Preoperative diagnosis can be challenging because of the many existing differential diagnoses upon imaging. Magnetic resonance imaging is the mainstay technique of imaging due to its multimodal nature.

A 66-year-old Arab woman with diabetes mellitus of 4 years' duration underwent transsphenoidal (TSS) resection of a nonfunctioning pituitary macroadenoma in May 2018. Her immediate postoperative course was free of events. Three months after the procedure (August 2018), she checked in to our institution with chronic headaches. Her physical examination showed bitemporal hemianopia. Relevant blood screening results were as follows: thyroid-stimulating hormone ultra sensible (TSHus), 0.3 mIU/L (normal range, 0.5–5); free thyroxine (FT4), 0.7 ng/dl (1–2); adrenocorticotropic hormone (ACTH) (8:00 a.m.), 3 pg/ml (10–40); cortisol (8:00 a.m.), 6 μg/dl (10–20); follicle-stimulating hormone (FSH), 20 IU/L (30–110 postmenopausal); luteinizing hormone (LH), 10 IU/L (15–54 postmenopausal); estradiol, 1.2 pg/ml (< 10 postmenopausal); growth hormone (GH), 2 ng/ml (< 10 [women]); prolactin, 0.7 ng/ml (2–20 [nonpregnant]); C-reactive protein (CRP), 2 mg/L (< 3.0); and white blood cells (WBC), 10.5 × 109/L (4.0–11.0 × 109/L).

Brain MRI showed a pituitary mass measuring 4 cm of the major axis, exhibiting low T1-weighted (T1w) signal, high T2-weighted (T2w) signal, and diffusion-weighted imaging (DWI) with rim enhancement after injection of gadolinium. The mass was responsible for a compression of the optical chiasma.

After hormone substitution therapy, endoscopic endonasal drainage via TSS route was performed, which brought back a purulent fluid with no macroscopic tissue fragments inside. Following the drainage and irrigation of the PA, the result of a close exploration was negative for the tumoral lesion. No intraoperative cerebrospinal fluid (CSF) leak in conjunction with a Valsalva manoeuvre. The closure was achieved with Gelfoam packing (Pharmacia and Upjohn, Kalamazoo, MI, USA) and Surgicel overlay (Ethicon, Somerville, NJ, USA). The purulent material grew a Streptococcus epidermidis, and histopathological examination showed no tumoral lesion. On the basis of the antibiotic sensitivity test, targeted antibiotherapy was administered for 3 weeks. The postoperative course was uneventful, with progressive improvement of the clinical state. Follow-up MRI at 3 months showed a very sizable reduction of the PA.

Patient 2

A 64-year-old Arab man with no major medical history consulted in December 2017 for chronic headaches and progressive vision loss, evolving for 1 year, with neither fever nor asthenia. His physical examination was remarkable only for a chiasmal syndrome. He did not have diabetes insipidus. Relevant blood screening results were as follows: TSHus, 0.25 (0.5–5); FT4, 0.7 ng/dl (1–2); ACTH (8:00 a.m.), 5 pg/ml (10–40); cortisol, 3 μg/dl (10–20); FSH, 0.7 IU/L (1,2,3,4,5,6,7,8,9,10); LH, 0.5 IU/L (0.7–7.9 [ages 20–70 years]); testosterone, 50 ng/dl (200–900 [male age > 19]); GH, 1.5 ng/ml (< 5 [men]); CRP, 3 mg/L (< 3.0); and WBC, 9.7 × 109/L (4.0–11.0 × 109/L).

Brain MRI showed a 3-cm pituitary mass with a cystic and hemorrhagic component; it was heterogeneous with mixed high and low T1w and T2w signalling, and it exhibited rim enhancement. DWI showed mild and partial high intensity in the central part of the mass.

At this stage, the two relevant differential diagnoses were pituitary adenoma (with necrosis and cyst degeneration) and PA. These MRI findings were mostly in favour of a remodelled pituitary mass. That is what was shown in the final MRI report.

After hormone substitution therapy, patient 2 underwent TSS surgery with the intraoperative discovery of a PA that was drained. No macroscopic tissue fragments were found inside the purulent matter. Following drainage and irrigation of the PA, the result of a close exploration was negative for the tumoral lesion. There was no intraoperative CSF leak in conjunction with a Valsalva manoeuvre. The closure was achieved with Gelfoam packing and Surgicel overlay. The purulent material grew Staphylococcus aureus, and histopathological examination showed no tumoral lesion. On the basis of an antibiotic sensitivity test, targeted antibiotic therapy was administered for 3 weeks. The postoperative course was uneventful, with progressive improvement of the clinical state. Follow-up MRI at 3 months showed complete drainage of the abscess.