Migratory polyarthritis as a paraneoplastic syndrome in a patient with diffuse large B cell lymphoma: a case report

BACKGROUND: Diffuse large B cell lymphoma is the commonest histological subtype of non-Hodgkin lymphoma and typically presents as a rapidly enlarging lymph node mass and B symptoms. It is unusual for diffuse large B cell lymphoma to present as carcinomatous polyarthritis which is a type of paraneoplastic arthritis. CASE PRESENTATION: We present a case of a 45-year-old Asian man with diffuse large B cell lymphoma presenting with generalized lymphadenopathy, transient macular rash, and migratory polyarthritis involving both upper and lower limb small and large joints. Treatment of the lymphoma but not the routine anti-inflammatory agents resulted in complete resolution of the arthritis suggesting the paraneoplastic nature. CONCLUSIONS: Poor response to routine therapy for inflammatory arthritis should lead to early suspicion of paraneoplastic arthritis which will prompt investigation for an underlying malignancy. Suspicion of carcinomatous polyarthritis should be made in those with migratory polyarthritis and should be thoroughly investigated to exclude underlying malignancy.