Case Report: Rare pulmonary infection and cytomegalovirus retinitis revealed a case of lymphoma

This case highlights that severe, unexplained immunodeficiency with recurrent CMVR and rare opportunistic pulmonary infections should prompt a high index of suspicion for underlying hematologic malignancy. mNGS and PET-CT are critical tools in the diagnostic workup, but definitive diagnosis relies on histopathological confirmation. Early recognition of such presentations can prevent delays in diagnosing aggressive lymphomas.