Cutaneous diffuse large B cell lymphoma mimicking extrapulmonary tuberculosis

The differential diagnosis for an adult cervical lymphadenopathy often includes infectious diseases and malignancy. Extrapulmonary tuberculosis (TB) is an infectious disease that can manifest with cutaneous lesions or tuberculosis lymphadenitis, which can present as a neck mass. Among other cancers, B cell lymphoma can also first present with cervical lymphadenopathy that appears as a firm neck mass. However, TB and B cell lymphomas differ in most other presenting signs and symptoms. In this case report, we present an unusual case of a patient who first presented with bulky, necrotizing masses, lymphadenopathy, and cutaneous lesions suspicious for extrapulmonary TB and was partially responsive to RIPE therapy. However, this patient was later diagnosed with atypical diffuse large B cell lymphoma (DLBCL) with cutaneous involvement, showing that cutaneous DLBCL can closely mimic the common signs of extrapulmonary TB.