A 43-year-old Japanese man visited a neighboring hospital complaining of dyspnea on effort, dry cough, and rhinorrhea for 2 weeks. He did not show any abdominal symptoms and had no cancer history. A chest computed tomography scan revealed diffuse centrolobular tiny nodules and thickening of both bronchovascular bundles and interlobular septa in lungs, and bronchiolitis and lymphangiosis carcinomatosa were suspected . He was admitted to our hospital for further examination and treatment. Laboratory tests showed the following findings: white blood cells, 13 990/μl; platelets, 229 × 103/μl; plasma D-dimer, 7.0 μg/ml (normal <2.0); carcinoembryonic antigen, 4.0 ng/ml (<5.0); CA19-9, 95.7 U/ml (<37); and vascular endothelial growth factor (VEGF), 832 pg/ ml (<120). His oxygen saturation was 90% when breathing room air. Antibiotic administration and oxygen supplementation therapy were performed, and a whole-body screening was planned. However, his respiratory condition deteriorated and, on the fifth day after admission, he suddenly complained of severe dyspnea and died.
Chest computed tomography scan showing diffuse tiny nodules and the swelling of bronchovascular bundles
A postmortem examination revealed an ulcerated tumor, measuring 12.5 × 9 cm, in the stomach angle. Histologically, the tumor was a poorly differentiated adenocarcinoma with remarkable lymphatic permeation that had invaded into the serosa. Multiple abdominal lymph nodes were involved. Ascites was 200 ml and peritoneal dissemination was absent. The left and right lungs weighed 620 and 740 g, respectively. Hemorrhagic infarctions were present in the right lower lobe, and macroscopic thrombi were absent in the pulmonary arteries. Microscopic examination revealed widespread fibrin thrombi and fibrocellular and fibromuscular intimal proliferation with or without gastric cancer cells, resulting in luminal stenosis and occlusion in the small pulmonary arteries [Figure , ]. These findings were compatible with PTTM. Lymphangiosis carcinomatosa and mediastinal lymph node involvement were also seen. Carcinoma cells in the stomach and lungs were immunohistochemically positive for VEGF . The heart weighed 385 g and showed dilatation of the right ventricle. The liver weighed 1 645 g and showed congestion, probably owing to congestive heart failure. Every organ except for the stomach lacked a space-occupying tumor mass.
(a) Obstruction of a pulmonary artery (H and E, ×40), (b) High-power view of an artery (H and E, ×400), (c) Immunopositivity for vascular endothelial growth factor among the tumor cells (×200)