A 71-year-old man visited our hospital for a second opinion on his worsening dyspnea, recurrent for more than 6 months. 6 months ago, he had started to present dyspnea on exertion, which eventually worsened; he was admitted at a tertiary hospital. At the hospital, pulmonary function test results were normal except for the diffusing capacity for carbon monoxide, at 22.4 mL/mmHg/min (29%). Chest CT showed diffuse GGOs in the both lungs and consolidation at the left lower lobe (Fig. 1A). Echocardiography showed a mildly thickened left ventricle wall and moderate resting pulmonary hypertension (The maximal tricuspid regurgitation velocity 3.6m/sec). Heart biopsy was done to rule out amyloidosis, which came out negative. Bronchoscopic alveolar lavage (BAL) procedure was carried out; the fluid cell count included a total of 640 white blood cells, 64% alveolar macrophages, 12% neutrophils, and 24% lymphocytes. Additionally BAL culture provided no definite finding, as no pathogens were detected, including Mycobacterium tuberculosis and nontuberculosis mycobacteria. Transbronchial lung biopsy was not performed because of hypoxemia during the examination.
These results, supplemented by others, prompted his attending physician at that hospital to explain to the patient that he was diagnosed as having suspected cryptogenic organizing pneumonia. Thus, the attending physician decided to treat him with 50 mg of intravenous methylprednisolone, as an empirical therapy. Initially, therapy was effective; however, upon gradual tapering of the steroid, recurrence of dyspnea on exertion occurred. Upon conducting a follow-up chest CT scan, newly developed multiple nodules were found to have been superimposed on GGOs in the both lungs (Fig. 1B). Subsequently, the patient visited our hospital for further evaluation and management of the worsening dyspnea.
The patient had type 2 diabetes mellitus, dyslipidemia, a duodenal ulcer, and benign prostatic hyperplasia. The patient stated that before the dyspnea occurred, he had smoked 15 cigarettes per day for 50 years, totally 37.5 pack years. His family history and alcohol history were nonspecific.
His vital signs showed blood pressure of 110 mmHg over 70 mmHg, heart rate of 93 beats per minute, respiratory rate of 22 breaths per minute, and body temperature of 36.4  C. His lung sounds were diffusely coarse in both sides. He had no cervical neck vein engorgement, organomegaly, or palpable mass.
In laboratory examinations, he had a white blood cell count of 5990/mm3 of blood (neutrophil 80.9%), hemoglobin concentration of 11.8 g/dL, platelet count of 71,000/mm3, 306 mOsm/kg serum osmorality, 128 mEq/L sodium, 4.1 mEq/L potassium, 97 mEq/L chloride, 3.6 g/dL total protein, 2.1 g/dL albumin, 566 mg/dL glucose, 0.5 mg/dL total bilirubin, 28 mg/dL blood urea nitrogen, 1.4 mg/dL creatinine, 32 IU/L aspartate aminotransferase, 31 IU/L alanine transaminase, 1.9 mg/L c-reactive protein, and 1707 IU/L LDH. Blood gas analysis showed pH 7.41, PaCO2 25 mmHg, PaO2 61 mmHg, and oxygen saturation level was 96% at receiving oxygen 3L/min via nasal prong.
Upon review of sequential chest CT at the previous hospital (Fig. 1) and high LDH level, we decided to perform SLB through VATS. On hematoxylin and eosin staining, pulmonary interstitium was filled with several atypical lymphocytes in the capillaries (Fig. 2). Immunohistochemical staining showed tumor cells were positive for CD20 (Fig. 3) and negative for CD3, S-100, HMB45, Pan-CK, CEA and CD31.
Finally he was diagnosed as IVLBCL of lung. We referred him to Seoul St. Mary's hospital. Before treatment, positron emission tomography-computed tomography (PET-CT) was done as a baseline study. We found no abnormal 18-fluorodeoxyglucose (FDG) avid lesion (Fig. 4). Thus, we could confirm him as IVLBCL of lung without any other organic involvement. He was treated with R-CHOP chemotherapy for six cycles.
One month later, he came back to the outpatient clinic of the hematology of Seoul St. Mary's hospital after completion of the chemotherapy. He said that he could climb mountain just like a few years ago and had no dyspnea at all. His lung sounds were clear without crackles. In laboratory examinations, he had a white blood cell count of 15,770/mm3 of blood (neutrophil 81.0%), hemoglobin concentration of 10.2 g/dL, platelet count of 281,000/mm3, 26.0 mg/dL blood urea nitrogen, 1.24 mg/dL creatinine, and 726 IU/L LDH. In radiologic findings, the comparison of sequential chest CT images before and after R-CHOP treatment were also compatible with complete remission of IVLBCL (Fig. 5). He went back home looking forward to his next visit to the hospital.