Intra-third ventricular craniopharyngiomas: imaging characteristics, histopathology and successful trans-lamina terminalis approach

Abstract

Craniopharyngiomas usually grow from remnants of Rathkes' pouch and frequently locate on the cisternal surface of the hypothalamic region. However, this tumor can grow exclusively within the third ventricle. During the past 18 years, five purely intra-third ventricular craniopharyngiomas were experienced in our institute. Four patients were male and the patient ages ranged from 13 to 52 years. Presenting clinical symptoms and signs included visual impairments in three, mental deterioration in two, headache and pituitary insufficiency in two. The histopathology was papillary and squamous in three and adamontimomatous in two. Precise tumor location and morphology were established with CT and MRI. The mass was solid and well enhanced in two patients, mainly solid with small rim enhancing cysts in two and multi-cystic with calcification in one. Hypothalamic brain edema was observed in a huge tumor of a papillary type. Spotty or massive calcification was noted in each of the two tumors of an adamantinomatous type. Although there are several surgical approaches available to resect an intra-third ventricular tumor, all our cases were operated through an interhemispheric trans-lamina terminalis approach. Gross total resection was performed in all cases at the initial surgery. Microsurgical findings revealed: (1) little or no tumor adhesion to the ventricular walls and the roof, (2) firm attachment to the floor of the ventricle around the vicinity of the tuber cinereum. The origin seemed to be the floor, (3) another important finding was small feeders coming from the anterior part of the circle of Willis. In order to get a direct view of the most delicate part of the tumor dissection, the trans-lamina terminalis approach was a valid choice. Recurrence was noted 8 months later in one patient followed by a total resection using the same route. No radiotherapy was applied in all patients. In the post-operative period, precise assessment of body fluid and hormone is mandatory and accurate replacement treatments are needed even months or years. All patients returned to their previous activity.