Cavernous angioma of the medulla oblongata

Clinical History

A 77-years-old male patient presented with dysphagia and dysarthria during the past 3 months. No other relevant symptoms related to the central nervous system were described.

Imaging Findings

Axial NECT (Fig. 1) shows a round haematic hyperdensity in the bulb, with negative axial reformatted CTA (Fig. 2). The patient underwent MRI, which showed a mass localized in a bulbar, median topography, grossly rounded, measuring about 17 x 17 x 27 mm (AP x transverse x height), with heterogeneous intensities on axial FLAIR (Fig. 3) and a haemorrhagic element, the last showing prominent hypointense "blooming" on axial T2* (Fig. 4). Comparing sagittal T1WI with (Fig. 5) and without contrast agent (Fig. 6), no enhancement was seen.

Discussion

Cavernous angioma, also known as cavernous malformation, cavernous haemangioma, arteriovenous malformation or cavernoma cryptogenic, is an uncommon vascular malformation of the central nervous system with a tumoral aspect [3].
It can be located in the brain, spinal cord and cranial nerves. It is a relatively rare disease, with an incidence in the population from 0.5 to 0.7%. Just about 25% are located in the lower (“infratentorial”) region [2].
Cavernomas contain blood products at various stages of evolution and are usually small (less than 3 centimetres in size) [1]. These lesions are difficult to detect on CT; they do not enhance. If large, a region of hyperdensity can be seen. Oedema can surround the lesion, especially if a recent haemorrhage has occurred.
MRI is the modality of choice, demonstrating a characteristic “popcorn” appearance with a hypointense rim due to haemosiderin, the last demonstrating prominent susceptibility effect on SWI [2, 3]. The signal on T1 and T2 varies according to the age of the blood products. The lesions generally do not enhance; on angiographic studies, cavernomas are angiographically occult.

About brainstem cavernomas, the most common symptom is focal neurological deficit as opposed to seizure or headache for lesions located in supratentorial regions. The risk of haemorrhage in that location is thirty times that of cavernomas located elsewhere [1, 2].
According to some articles, medulla oblongata is the region least affected, and may even represent only about 4-6% of cavernomas of the posterior fossa.

Differential Diagnosis List

Final Diagnosis

Cavernous angioma of the medulla oblongata.

URL:	https://www.eurorad.org/case/13610
DOI:	10.1594/EURORAD/CASE.13610
ISSN:	1563-4086