Cerebellar haemangioblastoma unveiled: Exploring a posterior fossa lesion in a young patient

A 22-year-old female, without significant medical history, presented to the emergency department with complaints of headache and double vision, which commenced following a head injury two weeks ago. She also reported nausea but no vomiting.

Computed Tomography (CT) revealed a rounded, well-defined intraaxial lesion with a cystic appearance, centrally located in the right cerebellar hemisphere-vermis. On the left side of the tumour, there was a solid eccentric nodule with intense homogeneous hyperenhancement. Slight surrounding oedema and signs of ascending transtentorial herniation and obstructive hydrocephalus were noted. No acute haemorrhage was observed. Magnetic Resonance Imaging (MRI) confirmed the CT findings and demonstrated the eccentric mural nodule with an elevated relative cerebral blood volume (rCBV) in T2* perfusion series, indicative of a vascular structure. There was no enhancement of the cystic component and no diffusion restriction. Angiography revealed a persistent tumour blush, dependent on a dominant arterial pedicle from the right superior cerebellar artery with a minor contribution from the left, and a draining vein to the straight sinus. The dominant arterial pedicle was embolised. Post-embolisation series demonstrated resolution of the tumour blush, with persistence of tumoural enhancement secondary to the left-side branch.

Background

Haemangioblastomas are benign neoplasms of vascular origin, originating in the central nervous system. They typically manifest in young or middle-aged adults [1]. While they are the most frequent primary intra-axial infratentorial tumours in this demographic group, they account for only 1–2.5% of all intracranial tumours and approximately 10% of all posterior fossa tumours [2]. Microscopy reveals a highly vascular tumour composed of neoplastic stromal cells and reactive vascular cells, resembling a capillary haemangioma [2].

Clinical perspective

In 30% of cases, these tumours are associated with von Hippel Lindau syndrome (VHL) [1], a dominant, autosomal disorder due to the mutation of the suppressor gene located on chromosome 3p25-26 [3]. It is also associated with renal cell carcinoma, cystic visceral tumours, adrenal pheochromocytoma, and papillary cystadenoma of the epididymis. The clinical presentation of haemangioblastomas is variable, with headache being the most prevalent symptom [3]. Other presentations include symptoms of elevated intracranial pressure, cerebellar dysfunction, altered mental status, and polycythaemia. Acute presentation due to significant haemorrhage is uncommon [2].

Imaging perspective

Supratentorial localisation is extremely rare [1]. Likewise, meningeal involvement is exceptional, with few cases reported in the literature [5]. These tumours generally appear as sharply demarcated homogeneous masses on imaging, comprising a cyst with non-enhancing walls and a mural nodule that enhances vividly (on non-contrast CT, the mural nodule is isodense to the brain) [4]. It is not uncommon for the mural nodule itself to have cystic spaces within it. Solid nodules are frequently seen abutting the pia mater. On MRI, haemangioblastomas appear as cystic lesions with signal intensity equal to the cerebrospinal fluid, with an eccentric mural nodule that is hypo-isointense on T1 sequences and hyperintense on T2 sequences, showing flow void images due to dilated vessels [6]. After contrast administration, there is intense enhancement of the mural nodule, without enhancement of the cyst wall. In MR perfusion series, a high rCBV ratio is shown [6]. Angiography shows enlarged feeding arteries and often dilated draining veins with a dense central tumour blush.

Outcome

Surgical resection is usually curative and, in the case of large lesions, may be facilitated by preoperative embolisation [1]. Adjuvant radiotherapy may be used in patients with incomplete resections [3]. Recurrence can be observed in up to 25% of patients [3]. A biopsy was performed, and histological sections confirmed the diagnosis of haemangioblastoma.