title: Pulmonary tumor thrombotic microangiopathy resulting from metastatic signet ring cell carcinoma of the stomach.
abstract: Pulmonary tumor thrombotic microangiopathy is an unusual malignancy-related respiratory complication characterized by multiple microthrombi and intimal myofibroblast proliferation. Its clinical manifestation is subacute respiratory failure with pulmonary hypertension. Herein is reported a case of pulmonary tumor thrombotic microangiopathy associated with gastric signet ring cell carcinoma. A 51-year-old woman with gastric cancer died of subacute respiratory failure. Autopsy showed gastric signet ring cell carcinoma with diffuse metastasis of pulmonary lymphatics and pleurae; every organ examined lacked a space-occupying tumor mass. Histologically, proliferated intimal myofibroblasts obliterated most of the pulmonary vascular lumen, and a few stenosed vascular lumina contained cancer cells. In addition, pulmonary vasculature associated with intimal proliferation contained microthrombi. Most cancer cells in the stomach and pulmonary lymphatics were typical signet ring cells, whereas those in vascular lesions were cells of poorly differentiated adenocarcinoma without mucous production. Consistent with a previous report, the latter expressed vascular endothelial growth factor (VEGF) and tissue factor (TF). The proliferated intimal myofibroblasts also expressed type 2A serotonin receptor (5-HT(2A)). These findings suggest that local expression of VEGF, TF, and 5-HT(2A) may be linked to the pathogenesis of this unusual pulmonary complication.
authors.affiliation: Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Honjo, Kumamoto, Japan. nanaomi@gpo.kumamoto-u.ac.jp
authors.forename: Naomi
authors.initials: N
authors.lastname: Sakashita
authors.forename: Chiharu
authors.initials: C
authors.lastname: Yokose
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Fujii
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Koji
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Motohiro
authors.initials: M
authors.lastname: Takeya
mesh_terms: D018279:Carcinoma, Signet Ring Cell / Q000150:complications / Q000378:metabolism / Q000556:secondary*; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000473:pathology; D008168:Lung / Q000098:blood supply* / Q000473:pathology; D008175:Lung Neoplasms / Q000150:complications / Q000378:metabolism / Q000556:secondary*; D008833:Microcirculation / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism; D012131:Respiratory Insufficiency / Q000209:etiology / Q000473:pathology; D013274:Stomach Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D013923:Thromboembolism / Q000473:pathology; D013925:Thromboplastin / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D044402:Receptor, Serotonin, 5-HT2A; D042461:Vascular Endothelial Growth Factor A; D013925:Thromboplastin