A 41-year-old female patient was referred to the ENT outpatient clinic with 5-month history of clear fluid discharging from the nose. Fluid samples were sent for tau protein analysis and outpatient imaging was requested. Prior to completion of skull base imaging, the patient was admitted in an acute confusional state, with a nonblanching rash, pyrexia, and signs of meningism. A diagnosis of streptococcal meningitis was made following lumbar puncture and she was commenced on appropriate antibiotics. Magnetic resonance imaging demonstrated an extensive skull base lesion involving the sphenoid and ethmoid sinuses, pituitary fossa, and suprasellar region (Figure 1). Computed tomography of the sinuses revealed bony destruction (Figure 2).
An endonasal transethmoidal biopsy was undertaken, following which there was profuse CSF rhinorrhoea. Subsequently, the patient developed clinical signs of meningism with pyrexia, neck stiffness, photophobia, and deterioration in neurological status. CSF analysis revealed gram-negative coliforms and antibiotic treatment was commenced.
The patient was transferred to the regional neuroscience centre for joint neurosurgical and ENT management. On recovery from the second episode of meningitis, she underwent an endoscopic endonasal biopsy and repair of the anterior pituitary fossa and planum sphenoidale using layered fat graft and artificial dural substitute sealed with Tisseel fibrin sealant (Baxter Healthcare, UK). Histological analysis of this biopsy specimen confirmed the tumour to be a prolactinoma. Although her initial serum prolactin level was only 451 miu/mL (normal range 102-496), it did rise to 953 miu/mL in the immediate postbiopsy period. Following endocrine review, she was commenced on cabergoline.
Despite satisfactory intraoperative appearances, CSF rhinorrhoea recurred. A CT cisternogram was undertaken to further characterise the site of CSF leakage (Figure 3). Through a sublabial transphenoidal microsurgical approach, two further repairs of bony defects in the floor of the pituitary fossa and roof of the sphenoid sinus were undertaken using fascia lata and fat grafts sealed with Tisseel glue, along with a period of postoperative lumbar CSF drainage. 
Both attempts were unsuccessful and lumbar CSF drainage resulted in profound pneumocephalus (Figure 4). The patient suffered a rapid deterioration in clinical status, and following two generalised tonic-clonic seizures required intubation and ventilation in the neurointensive care unit. 
Once sufficient neurological recovery had occurred, a second CT cisternogram (Figure 5) was undertaken prior to a further endoscopic endonasal repair using fat graft and fascia lata. In this procedure, 0 and 30  endoscopes (Karl Storz, Germany) and the Stealth Station Tria neuro-navigation system (Medtronic, USA) were used to locate and visualise the bony defects through a right-sided sphenoidotomy. Despite postoperative lumbar CSF drainage, this procedure was also unsuccessful.
Following the fourth unsuccessful attempt, the patient underwent a transcranial repair of the CSF leak through a right-sided pterional craniotomy. Intraoperatively, no dural defect was visible; however, bony defects in the anterior pituitary fossa floor were palpable and therefore sealed with layers of temporalis fascia and muscle grafts secured with Tisseel sealant. A prolonged post-operative period of lumbar CSF drainage (7 days) was also undertaken which resulted in a successful control of CSF rhinorrhoea.