LAUSR

Abstract Rationale: Nodal marginal zone B-cell lymphoma (NMZL) is a relatively rare indolent lymphoma that is the least common subtype of marginal zone B-cell lymphoma. Furthermore, coexistence of lymphoma and multiple myeloma (MM) is rare. Here, we report a case of the coexistence of NMZL and MM. Patient concerns: The patient was a 66-year-old man with pain in the left rib and lower left back. Enlarged lymph nodes were palpable in the cervical and inguinal regions, the biggest of which was 4.0 × 2.0 cm in size in the left groin. Diagnosis: Pathological and immunohistochemical findings of the left inguinal lymph node revealed NMZL. The patient met the diagnostic criteria for symptomatic MM. Therefore, the patient was diagnosed with NMZL and lambda-type MM. Intervention: We adopted a bortezomib, liposomal adriamycin, and dexamethasone (PAD) chemotherapy regimen mainly for MM. Outcomes: After 3 cycles of treatment, the patient achieved complete remission of myeloma. A 50% decrease in enlarged lymph node size was observed. Lesson: To our knowledge, this is the first case report of the simultaneous occurrence of NMZL and MM. Further studies are required to explain the association between these 2 tumors and improve treatment selection.