Authors: Lauren Lee, Michael Osswald: A 65 y.o. female with stage IV mantle cell lymphoma who underwent Maxi-CHOP therapy and achieved complete remission with high-dose BEAM conditioning and autologous peripheral blood stem cell transplant (PBSCT). After leptomeningeal relapse one year later, she underwent radiation therapy, systemic rituxan, and intrathecal MTX after which she received a match related donor allogeneic PBSCT with RIC Bu/Flu conditioning regimen. Her disease course was complicated by chronic graft versus host disease (cGVHD) despite immunosuppressive therapy. Notable on her peripheral blood smear were Howell-Jolly bodies, see image A. Review of repeat PET imaging revealed a markedly atrophied spleen, see image B. The pathogenesis of functional asplenia in bone marrow transplant patients with chronic graft versus host disease is not clear. Hyposplenia or functional asplenia is a well-established complication of bone marrow transplant. In such patients, increased frequency of infections is a major cause of morbidity and mortality despite aggressive antimicrobial prophylaxis. In patients with no prior history of splenectomy, non-visualization of the spleen may indicate functional asplenia. Imaging is often used to stage and evaluate the extent of underlying disease in this patient population. However, careful review of splenic size may serve as a predictor of those who are at increased risk for the development of chronic GVHD. Howell-Jolly bodies are classically seen in post-splenectomy patients, but may be seen in functionally asplenic patients.