In 30 autopsy cases of pulmonary tumor thrombotic microangiopathy, tumor cells within emboli were positive for vascular endothelial growth factor in 96.6% and tissue factor in 100% of cases, with a median survival of 9 days after oxygen supplementation.
Observational (n=30)
No
PTTM is a rare, rapidly fatal complication of carcinoma (most commonly gastric adenocarcinoma) characterized by pulmonary hypertension and hypercoagulability, with tumor cells frequently expressing VEGF and tissue factor.
OBJECTIVE: Pulmonary tumor thrombotic microangiopathy (PTTM) is a unique, rare and fatal form of pulmonary arterial tumor embolism. The aim of this study was to evaluate the clinical characteristics and pathological and immunohistochemical findings of PTTM. METHODS: Autopsy records dated between January 1983 and May 2008 in our hospital were reviewed, and those of patients who died from pulmonary tumor embolism resulting from malignant neoplasm were retrieved. The relevant tissue slides were reevaluated and examined immunohistochemically to confirm the diagnosis. RESULTS: Among 2,215 consecutive autopsy cases of carcinoma, 30 patients (1.4%) were diagnosed with definitive PTTM. The common symptom was progressive dyspnea. A hypercoagulative state was observed in all measured cases (n = 21). The chest computed tomography findings (n = 6) included consolidation, ground-glass opacity, small nodules and a tree-in-bud appearance. Perfusion scans were performed in seven patients, six of whom demonstrated multiple small defects. The median survival time after the initiation of oxygen supplementation was nine days. The most frequent primary site was the stomach (n = 18 ; 60%) , and the most frequent histological type was adenocarcinoma (28/30 ; 93.3%) . The immunohistochemical findings for tumor cells located within the tumor emboli were positive for vascular endothelial growth factor (28/29 ; 96.6%) and tissue factor (29/29 ; 100%). CONCLUSION: Clinicians should suspect PTTM in cancer patients who exhibit acute worsening respiratory insufficiency accompanied by a hypercoagulative state without embolism in major pulmonary arteries. The PTTM patients evaluated in our study had very poor prognoses. Vascular endothelial growth factor and tissue factor may play important roles in PTTM.
Uruga et al. (Tue,) conducted a observational in Pulmonary Tumor Thrombotic Microangiopathy (PTTM) (n=30). Pulmonary Tumor Thrombotic Microangiopathy (PTTM) was evaluated on Clinical characteristics and immunohistochemical expression of VEGF and tissue factor in tumor emboli. In 30 autopsy cases of pulmonary tumor thrombotic microangiopathy, tumor cells within emboli were positive for vascular endothelial growth factor in 96.6% and tissue factor in 100% of cases, with a median survival of 9 days after oxygen supplementation.