RARE-38. CNS LYMPHOMA INVOLVING HYPOTHALAMIC-PITUITARY AXIS

Abstract

Abstract BACKGROUND It is rare for CNS lymphoma which involves the hypothalamic-pituitary axis. It could result in misdiagnoses such as pituitary adenoma, craniopharyngioma, or glioma. We report clinical findings of eight cases of either primary or secondary lymphoma involving the hypothalamic-pituitary axis(H-P axis). METHODS We retrospectively reviewed 488 patients who were diagnosed as CNS lymphoma from 2000 to 2017 in our institute. There were eight patients (8/488, 1.6%) who had H-P axis involvement in radiographic findings while six patients received chemotherapy. We analyzed patient characteristics, pathologies, clinical features, laboratory findings, imaging, and treatment outcome. RESULTS The mean age was 48-year-old (range 18~80) and male to female ratio was 5:3. We performed endonasal TSA for four patients, endoscopic biopsy for two patients, and stereotactic biopsy for two patients. There were six patients of diffuse large B-cell lymphoma and two patients of MALT lymphoma. Seven patients were PCNSL and one patient was metastasized lymphoma. All patients had hormone imbalance whereas three patients had visual disturbance and one patient had diabetes insipidus. Initial serum LDH was 337±167IU/L(range 169~567 except one patient). MRI finding was different from the usual pattern which was low SI in T1 and high SI with perilesional edema in T2, on the other hands, our patients group revealed that five patients(62.5%) had iso SI in both T1 and T2, and only two patients(25%) showed perilesional edema in T2. Median OS and PFS of six patients who received chemotherapy were 34.8 months(range 0.9~93.7) and 33.0 months(range 0.9~93.4), respectively. Two patients(25%) died in 26 days and 51 days after diagnosis because of pneumonia and cardiac arrest, respectively. And one patient lost to follow up after diagnosis. CONCLUSION CNS lymphoma involving H-P axis is rare, however, we need to understand its unique characteristic.