Introduction: In this study, we analyse the clinical, radiological and pathological characteristics of recurrent cerebellar hemangioblastomas and highlight the factors causing recurrence.

Methods: 84 posterior fossa hemangioblastomas were operated between January 2000-September 2015 at our centre. These included 60 primary and 24 recurrent cerebellar hemangioblastomas (RCHs). In patients with RCHs, the location, multi-centricity, solid versus cystic lesions, associated Von Hippel-Lindau (VHL) syndrome, sites of involvement, extent of primary resection, surgical approach and histopathological features were assessed. 7 patients had brainstem and 4 had upper cervical involvement. Primary approaches included midline, paramedian and retromastoid sub-occipital craniectomy in 13, 7 and 4 patients respectively, which remained unchanged during re-exploration except in 4 patients. CSF diversion was done in 12 patients.

Results: 24 patients with RCHs underwent a total of 54 resections, with four patients undergoing three or more surgeries. Of these 24 patients, only five patients with sporadic tumors (n=19,26.3%) and two with VHL syndrome (n=5,40%) had brainstem involvement. 13 patients (9 isporadic and 4 VHL) had multicentricity with bilateral cerebellar involvement in 6 cases. 5 patients showed residual mural nodule after primary surgery. Time between first surgery-to-symptomatic recurrence ranged from 3-216 months. In contrast to thin, ectatic capillaries seen following primary surgery, recurrent lesions had micro-satellitosis, papillary tumor projections and plump, multilayered endothelium. The outcome was good except in one patient with VHL who succumbed to ARDS.

Conclusions: RCHs have frequently associated bilateral cerebellar or brainstem involvement, multicentric mural nodules, and/or VHL, and a a more invasive histology. Long term surveillance is mandatory. Awareness regarding factors precipitating recurrence may perhaps help in avoiding resurgery.

Patient Care: This study helps in identifying patients with cerebellar hemangioblastomas at risk of recurrence. It illustrates the fundamental pathological differences between primary hemangioblastomas and RCHs. It provides a roadmap for the management of recurrent tumors with emphasis on the need of long term surveillance.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of identifying factors responsible for causing recurrence in cerebellar hemangioblastomas. 2) Discuss, in small groups, the differences between sporadic and VHL associated recurrent tumours. 3) Learn the fundamental principles of management of RCHs and their surgical nuances.

References: 1. Lee G, Jung T, Kim I, Jung S, Jang W, Moon K et al. The clinical experience of recurrent central nervous system hemangioblastomas. Clinical Neurology and Neurosurgery. 2014;123:90-95. 2. Sharma B, Mehta V, Dwarakanath S, Suri A. Intracranial hemangioblastomas: An institutional experience. Neurol India. 2006;54(3):276.