Successful Anatomy Adapted Therapeutic Management and Genetic Profiling of Primary Pituitary Diffuse Large B-Cell Lymphoma

Primary pituitary diffuse large B-cell lymphoma (PPL) has been regarded as a subtype of primary central nervous system lymphoma (PCNSL); however, the pituitary gland is located outside the blood brain barrier (BBB) with neural and vascular connections to the brain. Given its unique anatomic location, a combination of non-central nervous system (CNS)-penetrating and CNS-penetrating therapeutic agents can be employed to treat PPL. We report a female patient with PPL who was successfully managed with anatomy-adapted therapy incorporating non-CNS penetrating chemoimmunotherapy [rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)] alternating with CNS-penetrating chemoimmunotherapy [rituximab, high-dose methotrexate, and high-dose cytarabine (RMA)]. She received a total of eight cycles of treatment with four cycles of each regimen following partial transsphenoidal resection. She achieved a complete response after two cycles and has remained in complete remission for the last eight years. To our knowledge, this is the longest documented survival in a patient with PPL. Targeted genomic profiling with Next-Generation Sequencing (NGS) was recently performed on the lymphoma tissue. The genomic profile of PPL in this patient is quite different from the findings typically associated with PCNSL. We suggest that PPL may be biologically distinct from PCNSL and should be treated with an anatomy adapted approach. Additional research is necessary to confirm our findings.