Primary central nervous system lymphoma involving the hypothalamic-pituitary axis: a case series and pooled analysis

Primary central nervous system lymphoma (PCNSL) involving the hypothalamic-pituitary axis (H-P axis) is a rare intracranial neoplasm. We aimed to determine the unique characteristics and treatment outcomes of patients with PCNSL at the H-P axis and review the literature.

We retrospectively reviewed the electronic medical records of patients with PCNSL in our institute from 2000 to 2017. We analyzed patient characteristics, clinicopathologic features, imaging results, and treatment outcomes. Furthermore, we searched the PubMed database and gathered more cases from published studies to analyze patient treatment outcomes.

A total of 488 patients were diagnosed with central nervous system lymphoma at our institute. Seven (1.4%) patients had H-P axis involvement, five had diffuse large B-cell lymphoma, and two had mucosa-associated lymphoid tissue lymphoma. All patients had anterior pituitary lobe dysfunction, and two had posterior lobe dysfunction. The median progression-free survival (PFS) for seven patients was 29.0 (range: 0.9-48.1) months, and the 3-year survival rate was 42.9%. Pooled analysis included 45 patients. The median PFS for these patients was 7.0 months (0.9-52.0), and the 2-year survival rate was 20%. Univariate and multivariate analyses revealed that the patients with visual field defects had better prognosis (p = 0.0153 and 0.043, respectively).

PCNSL at the H-P axis is associated with a higher rate of pituitary dysfunction than other parasellar pathologies. PCNSL at the H-P axis has a worse treatment outcome than PCNSL at other sites. However, visual field defect is related to a favorable prognosis in these patients.