Worm-like appearance of Listeria monocytogenes brain abscess: presentation of three cases.

Brain abscess caused by Listeria monocytogenes (LM) is a rare, yet serious condition with high mortality if not recognized and treated timely. We present a series of three cases of LM brain abscesses and describe their characteristic radiological appearances which can be considered very typical. LM abscesses frequently present as markedly irregular formations, revealing characteristic worm-like tubular pattern of chaotic curvilinear arrangement. Knowledge of this imaging pattern can be very helpful in early recognition of LM abscesses whose initial differential diagnosis can often be misleading initially.