A case of resected pulmonary lymphomatoid granulomatosis

Lymphomatoid granulomatosis (LYG) is a rare Epstein-Barr virus-associated B-cell lymphoproliferative disorder and was incorporated into the WHO classification of Tumours of the Lung, Pleura, Thymus and Heart in 2015. LYG is known to be associated with the host's immune function, and can be caused by some immunosuppressive agents, including methotrexate. A woman in her sixties with an 18-year history of methotrexate treatment for rheumatoid arthritis visited our hospital after detection of an abnormal chest shadow on her radiograph. She had been having anemia and a slight fever. Computed tomography (CT) revealed a 2.9-cm sized nodule in her left lung and hilar adenopathy, which suggested a primary lung carcinoma or an inflammatory lesion. We performed a left upper lobectomy with lymph node dissection for the purpose of diagnosis and treatment. Pathologic findings revealed that the tumor was a grade 3 LYG based on the number of EBV-positive B cells. The patient was treated with two chemotherapy regimens including R-CHOP at another hospital, and survived for four years after resection without recurrence in the lung. It is rare to find a case resected LYG, and the clinical or pathological findings of our case are expected to be extremely helpful in studying this disease and improving the understanding of this disease.