MM-170 Unique Pattern of Intracranial Relapse of Multiple Myeloma After Autologous Stem Cell Transplantation

Context: Multiple myeloma (MM) is a clonal plasma cell disorder that rarely involves the central nervous system (CNS). MM often affects the skull vault, but the involvement of the sella turca and brain parenchyma are extremely rare. We describe this atypical intracranial presentation in 4 MM patients each following an autologous stem cell transplant (ASCT). Objective: To describe clinical characteristics of a unique pattern of intracranial relapse in MM patients after ASCT. Design: Single-center retrospective study. Patients or Other Participants: We identified 4 patients (2 men, 2 women) with CNS relapse of MM each following an ASCT at Memorial Hermann Hospital, Texas Medical Center. Interventions: Three patients received systemic myeloma-directed treatment combined with local radiotherapy, whereas 1 patient received transsphenoidal resection of a sellar plasmacytoma. This last patient is followed at an outside institution where she is about to start radiation therapy after receiving endocrine replacement therapy. Main Outcome Measures: We analyzed clinical presentation, time interval from ASCT to relapse, site of relapse, treatment modalities, and outcome. Results: The subjects' races were White (n=1) and Black (n=3). Their mean age was 56 years. Three had revised international staging system (R-ISS) stage II disease, and 1 had stage III disease. Post ASCT, all received lenalidomide maintenance. The times to CNS relapse were 36, 22, and 17 months in patients with R-ISS stage II disease and 9 months in the stage III disease patient. Typically, the relapse was around the sellar region, involving the cavernous sinus, clivus, sphenoid bone, optic chiasm, and pituitary gland. Two patients had evidence of third and sixth cranial nerve palsy. Three patients had bone marrow and extracranial bony relapse of MM. Two patients underwent transsphenoidal resection of a pituitary mass. Patients with R-ISS stage II and stage III disease died 48 and 11 months after CNS relapse, respectively, and 2 remain on salvage therapy. Conclusions: CNS MM is a rare event associated with a poor prognosis. ASCT alters the natural course of MM, and disease relapses can occur in specific sanctuary sites. CNS involvement from MM should be considered in patients presenting with neurological symptoms following an ASCT. Timely recognition can avoid unnecessary surgical intervention.