Abstract Introduction Primary pulmonary lymphoma (PPL) is a rare lymphoid tissue malignancy, 3.6% of extranodal lymphomas and 0.3% of all lung neoplasms. There are several subtypes, Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), mucosa-associated lymphoid tissue (MALT) lymphoma, B-cell lymphoma, diffuse large B-cell lymphoma (DLBCL), and T/NK-cell lymphoma. We report this case to highlight the diagnostic complexity and importance of considering pulmonary MALT lymphoma in patients with non-resolving ground-glass opacities despite appropriate therapy. Presentation We present a case of a 76-year-old woman with a past medical history of gastroesophageal reflux disease (GERD). She had experienced progressive shortness of breath for several months prior to hospitalization and presented with acute hypoxemic respiratory failure. A CT angiogram (CTA) was negative for pulmonary embolism (PE) but revealed extensive, diffuse mixed alveolar and ground-glass consolidations throughout both lungs, accompanied by interlobular septal thickening. She was treated empirically with antibiotics, along with diuretics and corticosteroids, was discharged on home oxygen and a steroid taper due to concern for possible interstitial lung disease (ILD). A repeat CT scan eight weeks later showed no improvement in the diffuse opacities and nodularity. The patient subsequently underwent bronchoscopy with transbronchial biopsy and cryobiopsy, which revealed MALT lymphoma. She was evaluated by Hematology and Oncology and was started on lenalidomide and rituximab for disease control and palliation. Discussion MALT lymphoma is a rare clonal lymphoid proliferation that can affect one or both lungs. It occurs in both immunocompetent and immunocompromised patients and is not associated with smoking or occupational exposure. The median age at diagnosis is approximately 50 years. Symptoms are often nonspecific and may include weight loss, dyspnea, cough, fever, and loss of appetite. Diagnosis can be challenging; laboratory tests may show elevated LDH, monoclonal immunoglobulins, or increased C-reactive protein. CT findings are nonspecific and may demonstrate mediastinal lymphadenopathy or single/multiple pulmonary nodules measuring 2-8 cm, occasionally with cavitation. Diffuse involvement, as in this case, is a rare presentation. PET/CT typically shows variable FDG uptake. Bronchoalveolar lavage aids in excluding alternative diagnoses, while transbronchial biopsy confirms the diagnosis. Treatment includes surgical resection for localized disease and rituximab-based regimens for disseminated or unresectable tumors. The five-year survival rate is excellent (80-90%). Early recognition is crucial to prevent misdiagnosis and delays in appropriate therapy. Conclusion Pulmonary MALT lymphoma should be considered in patients with unexplained diffuse lung infiltrates unresponsive to standard therapies. Early tissue diagnosis prevents unnecessary treatment and improves outcomes. This abstract is funded by: None
Gelagutashvili et al. (Fri,) studied this question.