74-years old man was hospitalized because of non-ST elevation MI. He complained of chest pain and dyspnea even at rest. Dyspnea have been progressing during the past 3 months, while chest pain appeared 4 days before. Transthoracic echocardiography (TTE) () revealed mildly reduced left ventricle (LV) systolic function (LV EF 48%) with hypokinesis in inferior-posterior LV walls and mild pericardial effusion. Invasive coronary artery angiography () revealed three vessels disease: right coronary artery (RCA) - S2 – 95%, left anterior descending (LAD): S6 – 90%, S8 – 90%, S9 – 75%; left circumflex: S11 – 75%, S12 – 20%, S13 – 65%. Chest X-ray () showed homogeneous consolidation of the lower lobe of the left lung. Contrast-enhanced computed tomography (CT) () of the chest revealed a huge tumor (size 21 cm × 11 cm × 21 cm × 3 cm) in the anterior mediastinum with pronounced vascular network, displacing the surrounding organs. CT guided needle biopsy was performed. Histologically signs of a moderately-differentiated NETs were observed. Chromogranin A and 5-hydroxyindole-acetic acid were normal. Heart team together with oncologists decision was simultaneous operation - CABG and removal of the mediastinal tumor. Tumor () with a capsule was removed radically. It started from the root of the right lung to the left, partially grown with the right pulmonary vein and aorta. The pericardium was restored with a synthetic patch and CABG (venous grafts) were performed. Histological examination showed moderately differentiated NETs (). Tumor mitoses were found (2/10 mitoses/2 mm2), proliferation index was 2%. It was an infiltratively growing tumor formed by pseudo-rosette-like solid structures with a rim of relatively monomorphic, mitotically inactive cells with a chromatic nucleus and an average amount of light cytoplasm. Areas of necrosis were covering up to 20% of the tumor area. In two lymph nodes moderately differentiated NETs, G2 was also confirmed. Postoperative period was smooth. TTE after surgery showed preserved LV function and mild pericardial effusion. Somatostatin receptor scintigraphy showed no pathology, therefore control was planned after 3 months. Chest CT (6 months after operation) revealed the progression of the disease. Treatment with everolimus was started, but after 2 months life-threatening infectious complications were observed. The condition was assessed as pneumonitis or non-identified infection, therefore everolimus was stopped. The patient was observed and condition remained stable for 2 years. Two years later somatostatin receptor scintigraphy showed multiple tumors containing somatostatin receptors in the mediastinum, left lung, liver, and left peritoneum. Treatment with octeotride was started and gave positive dynamics observed on chest CT and decreased chromogranin A level. During next control chest CT, 6 months later, negative dynamics of the disease was observed, that is why capecitabine and temozolamide was added. 49 months after operation, he continues treatment by oncologists.