Five Cases of Primary Pulmonary Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma With Atypical Image Findings and Literature Review: A Case Series.

Primary pulmonary MALT lymphoma is a rare, indolent disease with nonspecific imaging often mimicking lung adenocarcinoma. We retrospectively analysed five patients (2020-2025) who underwent video-assisted thoracoscopic surgery (VATS) for suspected adenocarcinoma but were histopathologically diagnosed with MALT lymphoma. Notably, two patients presented atypically with pure ground-glass nodules (GGNs) and one exhibited a rare coexistence of bilateral consolidations and GGNs. At a median follow-up of 22.8 months, all patients remained disease-free or stable. In conclusion, diverse imaging manifestations, such as pure GGNs, complicate the diagnosis of pulmonary MALT lymphoma. Surgical resection is often a diagnostic necessity that also provides secondary therapeutic benefits for localised disease. Despite a generally favourable prognosis, long-term follow-up remains essential due to the potential risk of high-grade transformation.