Abstract
BACKGROUND
Atypical teratoid/rhabdoid tumor (AT/RT) Is a high-grade CNS malignancy predominantly seen in infants and children. AT/RTs occur throughout the neuraxis but have high predilection for midline structure such as pineal gland and brainstem. Suprasellar location is rare and pure third ventricular AT/RT is exceptional. We report a case of AT/RT in a young adult with third ventricle origin. This is the second documented case of adult third ventricle AT/RT.
MATERIAL AND METHODS
A 24-year-old male presented with two-week-long dizziness and diplopia. Magnetic resonance imaging (MRI) of the brain showed a heterogeneously enhancing large lesion in the third ventricle with isointense on T1WI and T2WI. Supratentorial ventricular space was enlarged with Evan’s ration of 33%. He underwent anterior transcallosal transchoroidal approach with gross tumor resection.
RESULTS
Postoperative course was uneventful with no hormonal deficiency. CSF diversion was not needed. Histopathological examination revealed AT/RT, WHO grade 4, with loss of SMARCB1 (INI 1) protein. H3 mutation was not found. He later underwent cranio-spinal irradiation with local booster followed by high dose chemotherapy (carboplatin, thiotepa and etoposide) with autologous stem cell transplantation. No recurrence was found on follow-up MRI at 10 months after operation.
CONCLUSION
AT/RT is a rare primary CNS tumor but their incidence among adults is being increased. We report a case of young adult AT/RT with very rare third ventricle location. AT/RT maybe considered as a differential diagnosis for suprasellar-third ventricle lesion in young adults.