Type:
Educational Exhibit
Keywords:
Multicentre study, Not applicable, Tropical diseases, Infection, Cysts, Education, MR, CT, Neuroradiology brain, CNS, Neuro
Authors:
F. D. G. Dantas1, T. A. L. Freddi2, A. D. F. Ferreira1, K. SAYEGH1, D. Costa1, A. Wolosker1, M. Borri1, N. Ferreira1; 1Sao Paulo/BR, 2Sao Paulo, SP/BR
DOI:
10.26044/ecr2020/C-04178
Findings and procedure details
According to the location of the parasite, NC can be divided into parenchymal and extraparenchymal forms which present with different clinical and imaging findings. Fig. 4 Parenchymal NC has four well defined anatomopathological stages — vesicular, colloidal, granular nodular, and calcified — which have a good correlation to imaging findings. It is worth noting that lesions of different stages can be found in the same patient.
In the vesicular stage, a cyst can be characterized next to the gray-white junction with a thin margin with a little or no contrast enhancement. A scolex can be seen within the cyst and is pathognomonic of NC. There is no inflammatory reaction in the surrounding brain parenchyma. Fig. 6 Fig. 7
In the colloidal stage, the larvae begin to degenerate determining edema surrounding the lesion and enhancement of the capsule. Fig. 8
In the granular nodular stage, the lesion retracts and forms a nodule that shows ring or solid enhancement with or without discreet surrounding edema. Fig. 9
The calcified stage demonstrates small areas of hypointensity on MRI, especially on SWI, and is considered a residual finding. Fig. 10 However, the onset of contrast enhancement and perilesional edema are consistent with reactivation. Fig. 11
Extraparenchymal NC includes intraventricular and subarachnoid forms. The intraventricular NC most commonly affects the IV ventricle, followed by the III ventricle, the lateral ventricles, and the Sylvius aqueduct. It is potentially lethal due to the risk of acute obstructive hydrocephalus. Fig. 12 Fig. 13 Ventriculitis and plexitis are also possible complications. Fig. 14
The subarachnoid NC frequently infiltrates the basal cisterns and sylvian fissure. Fig. 15 Cysts may become multiloculated and without scolex, characterizing the racemose form which is associated with leptomeningeal thickening, chronic meningitis, and vasculitis. Fig. 16 Fig. 17 Fig. 18 Fig. 19