Abstract Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is a rare, low-grade B-cell non-Hodgkin lymphoma that accounts for less than 1% of all pulmonary malignancies. It typically manifests radiographically as consolidative or nodular lesions, often with air bronchograms or bronchial involvement. The manifestation of pulmonary MALT lymphoma with ground-glass opacities (GGOs) is an exceedingly rare presentation that may obscure diagnosis and mimic inflammatory or infectious processes. We report a case of pulmonary MALT lymphoma presenting as ground-glass opacities without any initial distinct nodule. A 51-year-old female with a history of Sjogren’s syndrome, acquired hypothyroidism following radioactive iodine ablation for Graves disease, leukocytoclastic vasculitis, and gastroesophageal reflux presented to Pulmonology after incidental finding of ground glass opacities in the left and right lower lobe, measuring 7 mm and 5 mm respectively. She denied any respiratory symptoms and underwent surveillance with chest computed tomography (CT). On serial surveillance, CT showed a substantial increase in size of ground-glass opacity in the left lower lobe to 19 mm with a dominant solid component, as well as other ground glass nodules bilaterally. The patient subsequently underwent robotic bronchoscopy and mediastinal sampling with endobronchial ultrasound (EBUS) biopsy. Preliminary on-site cytology and Van Gogh tissue exam was suspicious for malignancy, however, final pathology report noted normal tissue. Due to conflicting findings, samples were sent to Mayo Clinic for a second opinion, with re-evaluation demonstrating atypical lymphoid proliferation containing a dense infiltrate of plasma cells, suggestive of MALT lymphoma. The patient was referred to oncology for further evaluation. While pulmonary MALT lymphoma most commonly presents with localized consolidations or peribronchial nodules, rare cases may show diffuse ground-glass attenuation due to infiltration of alveolar septa by neoplastic lymphoid cells. This atypical pattern may lead to initial misdiagnosis, including organizing pneumonia, hypersensitivity pneumonitis, or atypical infection. Recognition of this radiologic variant is essential to prompt tissue diagnosis, especially in patients lacking systemic lymphoma features. Ground-glass opacities represent an uncommon but important radiographic presentation of pulmonary MALToma. Awareness of this atypical manifestation expands the differential diagnosis for diffuse pulmonary GGOs and underscores the value of histopathologic confirmation in persistent or unexplained cases. This abstract is funded by: None
Tsai et al. (Fri,) studied this question.