Primary Pulmonary MALT Lymphoma: A Case Report and Literature Review.

Background: Primary pulmonary MALT (mucosa-associated lymphoid tissue) lymphoma is a rare entity that imposes a rigorous and demanding diagnostic work-up.

Case report: We present the case of a 74-year-old female non-smoker with a previous healed pulmonary tuberculosis and a history of arterial hypertension and fibromyalgia. She was referred to the pulmonology clinic to investigate a right inferior lobe (RIL) rounded pulmonary opacity (4 × 3.4 cm) identified on a previous thoracic CT scan performed for unrelated reasons. The remaining findings were non-specific and included small calcified mediastinal and hepatic adenopathies and multiple calcified hepatosplenic foci. The ¹⁸F-FDG-PET revealed high ¹⁸F-FDG uptake at the RIL lesion (SUV 4.7), suspicious for neoplastic involvement. Flexible bronchoscopy and CT-guided transthoracic needle biopsy were non-diagnostic and she was submitted to videothoracoscopy with surgical biopsy. The histological and immunohistochemical examination of the clear margin RIL segmentectomy were in keeping with a MALT lymphoma.

Conclusion: The authors present this case to highlight this rare entity, which is particularly challenging to diagnose due to non-specific multimodality imaging features, frequently implying more invasive procedures and surgical biopsy for a final diagnosis.