A 33-year-old male presented for resection of an intracranial mass after 1 year of recurrent headaches and dizziness. Cerebrospinal fluid testing had shown a lymphocytic pleocytosis (163 cells/mm3, 59% lymphocytes, 20% neutrophils) with normal protein (42 mg/dL), glucose (54 mg/dL), cultures, and serologic testing. Multiple brain magnetic resonance imaging (MRI) studies showed enlarged ventricles but no masses. Immediately before surgery, a discrete cystic structure was visible on imaging (Figure 1). A large cyst consistent with neurocysticercosis was identified intraoperatively. No additional lesions were observed, and he had complete resolution of symptoms. He received 7 days of albendazole, dexamethasone, and levetiracetam per guidelines for a solitary lesion.1 Follow-up imaging using higher resolution (1 mm versus 6 mm planes) and volumetric sequencing displayed an extra-parenchymal cyst with a visible scolex lateral to the fourth ventricle (Figure 2). As a result of surgical excision, there was no evidence of a residual fourth ventricle cyst. His MRI spine was negative, and he received two additional months of therapy until radiographic resolution, per guidelines for extra-parenchymal lesions.1 This thin walled extra-parynchymal cyst was uncovered with higher quality imaging using both finer planes and an ultrafast MRI technique known as volumetric imaging (e.g., fast imaging employing steady-state acquisition [FIESTA] sequencing). Ideally, higher quality imaging would have revealed these cysts preoperatively. However, his films were suggestive of mass lesion and thus volumetric imaging was not performed until the surgical pathology provided a definitive diagnosis. This case displays the role that high quality volumetric imaging plays in the diagnosis of neurocysticercosis.
(A) Gadolinium-enhanced magnetic resonance imaging (MRI) of the brain showing evidence of a fourth ventricular cystic structure. (B) Histopathology of a surgically removed cyst with i) cuticular layer with microvilli, ii) cellular layer, and iii) reticular layer. (C) Dissected cyst (neurocysticercosis) protruding from fourth ventricle. (D) Cyst post-excision.
Citation: The American Society of Tropical Medicine and Hygiene 91, 1; 10.4269/ajtmh.13-0441
Axial T2. Follow-up imaging 2 months post-surgical. (A) 1.2 cm cyst located at the right Foramen of Luschka (lateral recess of the fourth ventricle) consistent with neurocysticercosis cyst with internal scolex. (B) Post-surgical image displaying post-surgical changes to the fourth ventricle without evidence of residual cyst.
Citation: The American Society of Tropical Medicine and Hygiene 91, 1; 10.4269/ajtmh.13-0441
We thank Daniel Hawley of the NMCSD Department of Radiology and Jeffrey Tomlin NMCSD Department of Neurosurgery for their assistance with interpretation of the magnetic resonance imaging.
Nash TE, Singh G, White AC, Rajshekhar V, Loeb JA, Proaño JV, Takayanagui OM, Gonzalez AE, Butman JA, DeGiorgio C, Del Brutto OH, Delgado-Escueta A, Evans CA, Gilman RH, Martinez SM, Medina MT, Pretell EJ, Teale J, Garcia HH, 2006. Treatment of neurocysticercosis: current status and future research needs. Neurology 67: 1120–1127.