Pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma): Clinico-radiologic features, diagnosis, and outcomes

Pulmonary marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALToma) is the most common form of primary pulmonary lymphoma. Data on clinic-radiologic presentation, diagnostic methods, and clinical outcome are relatively sparse.

Retrospective study of 71 patients with biopsy-proven pulmonary MALToma encountered at Mayo Clinic from 1998 to 2022.

Median age was 63 years (range: 41-87) and included 42 females (59 %). Most patients (60.6 %) were asymptomatic; most common symptoms were cough (23.9 %), dyspnea (19.7 %), chest pain (5.6 %) and fatigue (5.6 %). Predisposing systemic disorder was present in 23 (32.4 %) patients, most commonly primary Sjogren syndrome (19.7 %). Diagnosis was achieved by surgical lung biopsy, core needle biopsy, transbronchial biopsy, and fine needle aspirate in 42 (60 %), 21 (29.6 %), 7 (10 %), 1 (1.4 %) patient, respectively; diagnostic rates were 100 %, 72.4 %, 41.2 % and 33 %, respectively. On chest CT scan, the most common type of abnormality was consolidation in 62 (87 %) and nodular/mass-like lesions in 62 (87 %) cases; air-bronchogram was present in 50 (70.4 %) cases. These findings were multilobar and bilateral in 45 (63.4 %) and 43 (60.6 %) cases, respectively, with no predominant distribution. Over one-third did not need treatment and pulmonary MALToma was an uncommon cause of death.

Pulmonary MALToma most commonly manifests during the 7th decade of life with more than half of patients being asymptomatic at presentation. Most frequent imaging findings include bilateral areas of consolidation and/or nodular/mass-like lesions commonly associated with air-bronchogram. Pulmonary MALToma is typically indolent and uncommonly causes death.