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Updated: Jun 21, 2026
Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study
Published on: August 15, 2025
Brain tumors in the mesial temporal lobe: long-term oncological outcome
1Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea.
Object:
Surgical treatment of brain tumors in the mesial temporal lobe (MTL) is a highly demanding procedure. Only a few studies describing the surgery of MTL tumors have been reported, and they have been focused on the operative techniques and immediate results of the surgery. The authors have analyzed the long-term oncological outcome in patients with MTL tumors.
Methods:
Thirty-six patients with an MTL tumor were studied. The mean patient age at surgery was 32 years (range 13-62 years). The tumors were confined to the MTL (Schramm Type A) in 25 patients (69%). Extension of the tumor into the fusiform gyrus (Schramm Type C) and temporal stem (Schramm Type D) was observed in 4 and 7 patients (11 and 19%), respectively. There was a significant difference in the tumor size according to Schramm types (p = 0.001). Complete tumor resection was achieved in 26 patients (72%). All tumors were low-grade lesions except for 1 anaplastic astrocytoma.
Results:
After a median follow-up period of 50.5 months, 7 patients showed progression of the disease. The actuarial progression-free survival rates were 97% in the 1st year, 84% in the 2nd year, and 80% in the 5th year. The degree of tumor resection was significantly related to the tumor control failure (p < 0.001) and malignant transformation of a low-grade tumor (p < 0.001). Univariate analyses using a Cox proportional hazards model showed that the following factors were significantly associated with a failure to control the tumor: 1) extent of the tumor (Schramm Type D; p = 0.003, relative risk [RR] 12.04); 2) size of the tumor (p = 0.033, RR 1.052/mm); 3) patient age at surgery >or= 50 years (p = 0.007, RR 8.312); and 4) short duration of epilepsy (< 6 months; p = 0.001, RR 21.54).
Conclusions:
Surgery is the principal treatment for MTL tumors, despite its technical difficulty. Complete tumor resection is strongly recommended for long-term tumor control. The MTL tumors are heterogeneous in their prognosis. Older age, short duration of epilepsy, and tumor size are all associated with poor outcome. Patients with these characteristics may have a more aggressive form of the disease than those with MTL tumors associated with chronic epilepsy.
Insights
Complete resection of mesial temporal lobe (MTL) tumors is crucial for long-term control. Factors like tumor extent, size, older age, and short epilepsy duration predict poorer outcomes in MTL tumor patients.
Area of Science:
- Neurosurgery
- Oncology
- Neurology
Background:
- Mesial temporal lobe (MTL) tumors present surgical challenges.
- Limited studies focus on long-term oncological outcomes of MTL tumor surgery.
Purpose of the Study:
- To analyze the long-term oncological outcomes in patients who underwent surgery for MTL tumors.
Main Methods:
- Retrospective study of 36 patients with MTL tumors.
- Tumor characteristics (Schramm type, size) and resection extent were recorded.
- Follow-up for oncological outcomes, including progression-free survival.
Main Results:
- Complete resection achieved in 72% of patients.
- 5-year progression-free survival rate was 80%.
- Tumor extent (Type D), larger size, age ≥50, and short epilepsy duration (<6 months) were associated with poor outcomes.
Conclusions:
- Surgery is the primary treatment for MTL tumors.
- Complete resection is vital for tumor control.
- MTL tumors have heterogeneous prognoses; certain factors indicate aggressive disease.
