Presentation
Complaints of limb weakness, no other specific symptoms, seizures or use of medications.
Patient Data
Magnetic resonance (MR) imaging with gadolinium shows a small cyst located at the quadrigeminal cistern, following cerebrospinal fluid (CSF) signal in all pulse sequences, homogeneously hypointense on T1 weighted MR and FLAIR images, and hyperintense com T2 weighted MR, without contrast enhancement. The cyst does not restrict on diffusion-weighted images, and it shows facilitated diffusion. It measures 1,6 x 1,6 x 2,0 cm. The cyst is exerting slight compression over the cerebellum. There is no compression on the aqueduct and no hydrocephalus.
Case Discussion
Arachnoid cysts are extra-axial non-neoplastic, cystic lesions, filled with CSF, lined with arachnoid membranes 1-3. It is a common incidental discovery on neuroimaging in all age groups, and are more common asymptomatic and usually do not require surgery 2,4. Symptoms and signs of arachnoid cysts depend on their size and location 3.
Quadrigeminal cistern arachnoid cysts occur between the collicular plates and the incisura notch of the tentorium. The symptomatology of quadrigeminal arachnoid cysts vary according to their size and depends on the severity of the compression on the tectal plate, brain stem, cerebellum, and aqueduct 3. Small cysts have a long-standing benign course and are usually asymptomatic 3.
This case describes the typical features of a small quadrigeminal cistern arachnoid cyst, which has a benign course, requiring observational and follow up.
Case courtesy
- Erick Cavalcante, MD - PGY-3, Radiology Resident, Department of Radiology
- Antonio Rodrigues de Aguiar Neto, MD - Radiologist, Department of Radiology
- Hospital da Restauração – Recife, PE – Brazil
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