A case of delayed intracerebral abscess due to Proprionibacterium acnes (P. acnes), 18 months after an uneventful excision of a parasagittal haemangiopericytoma in a 61-year-old female is reported. This is highly unusual as cerebral abscess by P. acnes is rare and it occurred so late postoperatively in the absence of known risk factors. We propose the inclusion of cerebral abscess by P. acnes in the differential diagnosis of lesions that mimic tumour recurrences, after clean craniotomies.

A 25-year-old woman, who was 25 weeks pregnant, underwent insertion of a VP shunt for hydrocephalus, secondary to a bithalamic glioma. Two months later, she represented with symptoms of raised intracranial pressure and MR scan revealed increased ventricular size. On exploration of the shunt, manometry with saline confirmed blockage of the catheter distal to the valve. On re-opening the abdominal wound, the peritoneal catheter was found to be knotted, 2 cm from the end. This segment of the catheter was replaced, with resolution of symptoms, post-operatively. The present case illustrates that a knot in the peritoneal catheter is an extremely rare cause of shunt malfunction. Possible mechanisms underlying it are discussed.

A peri-operative protocol involving mechanical anti-embolism stockings, adequate hydration, and early post-operative mobilisation is effective in significantly reducing the incidence of VTE. The addition of LMWH is safe in patients at higher risk of developing VTE. Cite this article: 2017;99-B:1204-9.

Although they are one of the most common brain tumours in childhood, piiocytic astrocytomas are rare in adulthood. We report a series of three piiocytic astrocytomas presenting as an intra/suprasellar mass in the fourth to sixth decades of life. All three radiologically mimicked the appearance of a craniopharyngioma, thus representing a potential radiological and diagnostic pitfall. In this series all three patients underwent successful operative management and have remained well throughout follow-up. The majority of information concerning piiocytic astrocytomas is derived from paediatric populations and so only limited and often conflicting data exist for piiocytic astrocytomas developing in adulthood. Decisions regarding treatment of piiocytic astrocytomas in adults must be made on a multidisciplinary, case-by-case basis.

Giant pituitary adenomas causing hydrocephalus are rare (Scarone P, Losa M, Mortini P, Giovanelli M. J Neurooncol 2006;76:51-4; Zikel OM, Atkinson JL, Hurley DL. Mayo Clinical Proc 1999;74:475-7). Guidelines for management of this rare condition are missing. Here we present a five-case series collected over 22 years. We suggest that where the two conditions coexist, the safest option is to insert an external ventricular drain prior to any definitive surgical intervention.