A 20-year-old lady presented with a 6 months history of progressive headache and memory disturbances. Few days prior to presentation, she had three episodes of generalized tonic clonic seizures. She also had gait disturbances and severe giddiness. Higher mental function examination revealed impaired recent memory. Fundoscopic examination showed bilateral papilloedema. Cranial nerve examination, motor and sensory examination was normal. Plantar reflexes were extensor on both sides and Romberg's sign was positive. Computed tomography (CT) scan of the brain showed isodense lesion located at foramen of Monro with hyperdense areas suggestive of hemorrhage with foraminal obstruction. The lesion was not enhancing on contrast []. Magnetic resonance imaging (MRI) brain revealed obstructive hydrocephalus due to a large lesion in the third ventricle which was homogenously hyperintense on T1-weighted images and homogenously hypointense on T2-weighted images [].\nRight lateral ventricle was entered via right frontoparietal craniotomy and an interhemispheric transcallosal approach. A grayish red, well-defined, soft to firm lesion was reached through the interforniceal approach. Needle aspiration was attempted but was unsuccessful. The surface of the cyst was vascular, so it was coagulated. The cyst wall was thickened and its separation from surrounding tissue was difficult. On opening the cyst, there was no colloid material, but a brownish yellow organized clot was found which was removed piecemeal. The clot was easily separated from the inner cyst wall. After almost complete evacuation of cyst content, the thick wall was held with biopsy forceps with one hand and with the other hand it was dissected from the surrounding parenchymal tissue. A complete excision of the cyst was ensured. Both internal cerebral veins were seen and found intact. Pathological examination confirmed hemorrhage within the colloid cyst. Microscopic examination also showed blood clots containing hemosiderin laden macrophages and many rhomboid cholesterol crystals and chronic inflammatory cells []. Post-operatively she had no seizures. Her memory function completely improved over a 3 week period.
We present a case of a 36-year-old male who was admitted to the hospital due to a 1-month history of daily headaches within the occipital region. The headaches were reported to be worse at night and occasionally accompanied by nausea and dizziness. Neurological examinations revealed a right-sided exaggerated tendon reflex compared to the contralateral side. The patient was diagnosed with a positive pyramidal syndrome, Hoffmann’s reflex, and Babinski’s and Rossolimo’s sign on the right side. A CT scan revealed a 20 × 15 × 23 mm isodense focal lesion in the posterior fossa at the level of the foramen magnum []. The lesion extended to the level of the dens of axis while compressing the spinal cord posteriorly. Proton density [], T1 [ and ], and T2 [ and ] weighted MRI scans revealed a 22 × 11 × 33 mm well-defined cystic mass with two heterogeneous compartments within the foramen magnum at the level of C1-2. The medulla and spinal cord were shown to be displaced and compressed along with remodeling of the vertebral arteries with the right artery mainly affected. The superior half of the lesion was hyperintense on T2WI [] and moderately hypointense on T1WI MRI []. The inferior half of the lesion was hypointense on T2WI and hyperintense on T1WI MRI. No enhancement was shown after contrast administration. After careful consideration, the far lateral approach was chosen, and the patient underwent preparation for the procedure. A J-shaped skin incision followed by a suboccipital craniotomy, C1 laminectomy, and a C2 hemilaminectomy was performed. The dura was opened, exposing the extramedullary cyst. Complete resection (CR) was achieved and a cranioplasty with a typical closure concluded the operation. A histological examination revealed the cyst to be most consistent with a type B NC. The postoperative course was uneventful, and the patient was discharged on the 7th day without any neurological deficits. In a later follow-up, a CT scan revealed no sign of cyst recurrence.