Neurocysticercosis of the Sellar Region

Fig. 55.1

Racemose neurocysticercosis in the pituitary gland. (a) Sagittal MR section showing many cystic membranes without a scolex in grapelike clusters in the sellar and suprasellar regions, suggesting racemose neurocysticercosis. Also shown are some single cysts in the cerebellum and brainstem. (b) Coronal section showing racemose neurocysticercosis of sellar and suprasellar regions. Some single cysts are also present in the grey–white matter junction of the cerebral cortex. (c) Axial section showing racemose neurocysticercosis of sellar and suprasellar regions. Single cysts can be seen in the grey–white matter junction of the cerebral cortex (Adapted from Dutta et al. [1], with permission)

55.2 Imaging Features

Sellar region cysticercosis may be identified in the sella, in the suprasellar region near the infundibulum and hypothalamus, or in the basal cisterns adjacent to the suprasellar space.
Isolated sellar cysticercosis cysts represent nearly half of cases, with the remaining patients having evidence of extrasellar or disseminated CNS involvement [3].
Sellar region cysticercosis may mimic a cystic pituitary adenoma, arachnoid cyst, Rathke cleft cyst, or craniopharyngioma [5, 6].
CT images often demonstrate bony expansion and erosion of the sella, a hypodense cystic lesion, and occasionally calcification in the mass or in other brain regions, lending support to the diagnosis of cysticercosis [5].
On MRI, cysticercosis cysts typically have low or high T1 signal and heterogeneous contents [2, 5].
Enhancement and thickening of the infundibulum may be seen on MRI [7].
Leptomeningeal enhancement in the parasellar region also may be seen [2].

55.3 Histopathology

The parasitic wall is characterized microscopically by wavy, dense cuticle and focal globular structures, often suggesting the scolex of the cysticercus [7].
A surrounding inflammatory, mononuclear lymphocytic reaction with plasma cells is often observed.
A variable degree of eosinophilia may be seen.