Posted: Wednesday, March 8, 2023
A case presentation published in the World Journal of Surgical Oncology highlighted the detection of a collision tumor that led to the rare diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma in both the thymus and lung. Liu et al, of the Affiliated Tai’an City Central Hospital of Qingdao University, China, and colleagues noted that Sjögren’s syndrome and a rare occurrence of concomitant adenocarcinoma were also found in the lung.
Physical examination of a 32-year-old asymptomatic female patient (with no history of smoking or other medical conditions) that revealed an anterior mediastinal mass. Blood tests, lung cancer–related tumor markers, and liver and kidney function were all within normal ranges; however, an enhanced chest CT showed a soft-tissue density in the thymus and a node in the upper lobe of the right lung, suggesting thymoma.
A thoracoscopy-guided total thymectomy and wedge resection of the lung enabled the removal of a cystic solid mass from the thymus and a nodule and mass from the upper and lower lobes of the right lung, respectively. Both specimens underwent histopathologic and immunohistochemistry examination. Polymerase chain reaction (PCR) gene scans of the masses were performed because of an atypical histopathologic presentation. Cytogenetic characteristics were examined using fluorescence in situ (FISH).
Results for lymphoma kinase break apart, MALT lymphoma–associated translocation 1 break apart, immunoglobulin heavy locus break apart, and trisomy 3 were all negative for the thymus and lung masses. However, immunohistochemistry indicated mature B lymphocytes in the thymic mass, and lymphoid follicle formation and lymphoepithelial lesions confirmed a diagnosis of thymic MALT lymphoma. In addition to histopathologic examination of diseased tissue, PCR and FISH results led to a final diagnosis of pulmonary MALT lymphoma, as well as microinvasive adenocarcinoma in the upper lobe of the right lung. Moreover, results of a labial gland biopsy and antibody testing led to an additional diagnosis of Sjögren’s syndrome.
Disclosure: The study authors reported no conflicts of interest.
World Journal of Surgical Oncology