Pulmonary tumor thrombotic microangiopathy: a systematic review

Abstract

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal disease process in which pulmonary hypertension (PH) develops in the setting of malignancy. The purpose of this study is to present a detailed analysis of cases of PTTM reported in literature in the hopes of achieving more ante-mortem diagnoses. We conducted a systematic review of currently published and available cases of PTTM by searching the term “pulmonary tumor thrombotic microangiopathy” on the Pubmed.gov database. Seventy-nine publications were included consisting of 160 unique cases of PTTM. The most commonly reported malignancy was gastric adenocarcinoma (94 cases, 59%). Cough and dyspnea were reported in 61 (85%) and 102 (94%) cases, respectively. Hypoxemia was reported in 96 cases (95%). Elevation in D-dimer was noted in 36 cases (95%), presence of anemia in 32 cases (84%), and thrombocytopenia in 30 cases (77%). Common findings on chest computed tomography (CT) included ground-glass opacities (GGO) in 28 cases (82%) and nodules in 24 cases (86%). PH on echocardiography was noted in 59 cases (89%) with an average right ventricular systolic pressure of 71 mmHg. Common features of PTTM that are reported across the published literature include presence of dyspnea and cough, hypoxemia, with abnormal CT findings of GGO, nodules, and mediastinal/hilar lymphadenopathy, and PH. PTTM is a universally fatal disease process and this analysis provides a detailed examination of all the available published data that may help clinicians establish an earlier diagnosis of PTTM.

Fatal progressive right heart failure in a pancreatic cancer patient

“…In laboratory tests, elevations of D-dimer, anemia, thrombocytopenia, and elevation of serum lactate dehydrogenase are the most common elevations but are non-specific [7]. In radiologic studies, centrilobular nodularity, ground glass opacity, and interlobular septal thickening have been reported in high resolution CT as in this case, but these findings may be seen in other lung diseases such as interstitial pneumonia [2].…”

“…Most cases of PTTM were diagnosed postmortem with ~79% of reported PTTM due to rapidly aggravating clinical course and fatal prognosis. PTTM tends to be under-diagnosed as most patients' families do not request an autopsy [7].…”

“…Alternatively, cytological examination of aspirated blood using a wedged pulmonary artery catheter with a sensitivity of 80%-88% and specificity of 82%-94% can be done. Additionally, if the TTE results are ambiguous, right heart catheterization may be useful for a more accurate assessment of PH [2,7].…”

“…Furthermore, the mean duration of death after dyspnea was reported to be 16.2 days. Once the dyspnea occurs, the patient appears to experience rapid deterioration [7,8]. Various therapeutic methods including medical and oxygen therapy have been attempted, but no consensus has been established.…”

“…Thrombolysis is known to have no benefit. Anticoagulation appears to improve prognosis, but the evidence for its efficacy is weak [7]. There is no evidence that endothelin receptor antagonists, such as bosentan and ambrisentan, reduce pulmonary vascular remodeling but can be used to reduce pulmonary vasoconstriction [3].…”