Primary pulmonary MALT lymphoma presenting as non-resolving pneumonia.

Primary lung lymphoma (PLL) is a rare unilateral or bilateral lung disorder that is challenging to diagnose solely based on clinical and radiological presentation. PLL may be misdiagnosed as pneumonia or a lung tumor due to non-specific findings. PLL is most frequently a mucosa-associated lymphoid tissue (MALT) lymphoma, a type of extranodal low-grade B-cell lymphoma most commonly discovered in the gastrointestinal tract. PLL should be considered in the differential diagnosis of non-resolving pneumonias. Herein we present a case of an 84-year-old patient discovered to have a primary pulmonary MALT lymphoma presenting as a non-resolving pneumonia causing a clinical challenge.