DX: Venous angioma (Developmental Venous Anomaly, DVA)

In the images, we see a "tunnel-like" flow void in left parietal region that apparently has cortical origin. It enhances with Gadolinium but has a unique morphology. On it's tip, we see a capillary nidus that resembles the head of a medusae or an umbrella. This is consistent with a particular Arterio-venous Marlformation type that mostly consists of enlarged anomalous veins called Venous Angioma.

A venous angioma, also referred to as a "developmental venous anomaly" (DVA) or sometimes "venous malformation" is basically an extreme variation of veins draining normal brain tissue in that region. That is, a venous angioma (DVA) by itself isnot necessarily "abnormal"; it's rather a variation of normal. However, having stated this, it should be noted that some studies have found that some veins (or all veins) that comprise a venous angioma have structural abnormalities compared with more normal veins. Regardless, most neurosurgeons regard venous angiomas by themselves as extreme variations of normal venous drainage.

The veins that comprise a venous angioma usually form a little cluster ("star burst" or "caput Medusae" - looks like a "head of snakes"), and these veins generally drain into a larger "collector" vein. The collector vein is usually on the surface of the brain, but sometimes there may be deep drainage too. The pattern (arrangement) of these veins is frequently simple, but may at times be more complex looking. Between the veins that make us the venous angioma is normal brain tissue. Sometimes one or more of these veins can appear extra dilated and may be more thin walled than other veins in the brain. Venous angiomas tend to occur near the frontal horns of the ventricles (fluid filled spaces of the brain) and also in the cerebellum (small part of the brain at the lower back part of the head).

Importantly, venous angiomas are frequently associated with cavernous malformations (cavernomas) and it is through this association that trouble potentially arises. Venous angiomas on their own don't tend to cause any trouble and, with few (reported) exceptions, should generally be left alone like this case.

Thank you Dr. Rammohan Vadapalli, Hitender Himral, Ruchi Gupta, Mayur Kulkarni for your great comments on FB groups!

Until next time.

http://journal.nzma.org.nz/journal/120-1250/2449/

http://www.brain-aneurysm.com/dva.html

http://www.mayfieldclinic.com/PE-AVM.htm

http://radiopaedia.org/cases/venous-angioma