BACKGROUND: Splenic marginal zone lymphomas (SMZLs) are generally uncommon, indolent lymphomas that typically affect older adults, but the development of the transformation to high-grade lymphoma may occur in a small proportion of patients and represents a rare event with blastic cell infiltration in the lymph nodes and bone marrow.

CASE REPORT: Here, we present a young adult patient who was diagnosed with a SMZL and developed a high-grade transformation to diffuse large B cell lymphoma (DLBCL) with central nervous system involvement. The patient was a 31-year-old woman whose hematologic medical history began with severe anemia and thrombocytopenia associated with atypical lymphoid infiltrate in the bone marrow and massive splenomegaly. A splenectomy was performed and revealed the SMZL. She was first treated with the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) and subsequently with the R-FMD regimen (rituximab, fludarabine, mitoxantrone, and dexamethasone) because the peripheral blood leukocytes were remarkably increased postoperatively. Six months after the splenectomy, she complained of headaches. A magnetic resonance imaging scan of her brain revealed intracerebral tumorous lesions from which a biopsy was taken. On morphological and immunohistochemical examination, the tumor fulfilled the criteria for a DLBCL. Treatment with pulse-dose intravenous methylprednisolone followed by high-dose methotrexate was promptly initiated, but the patient’s condition continued to deteriorate and she died of the disease 13 months after the splenectomy.

CONCLUSIONS: Although there is a general tendency for SMZL to display low aggressiveness, central nervous system involvement associated with a histological transformation to high-grade lymphoma, as presented here, can occur in advanced stage of the disease.

Keywords: Diagnosis, Lymphoma, B-Cell, Marginal Zone, Lymphoma, Large B-Cell, Diffuse