Pulmonary Tumor Thrombotic Microangiopathy: Clinical, Radiologic, and Histologic Correlation

Abstract

Pulmonary tumor thrombotic microangiopathy (PTTM) is a clinicopathologic disease entity in which the tumor cells embolize to the pulmonary vasculature leading to a series of maladaptive reactions including the activation of coagulation and fibrocellular intimal thickening. The resultant stenosis of blood vessels leads to pulmonary hypertension and eventual death from cor pulmonale. In this report, we present a case of PTTM presenting as the initial manifestation of metastatic gastric carcinoma in a young man. Although unusual in its occurrence as the initial manifestation of gastric carcinoma, the case is illustrative in its clinical, radiological and histological presentation.

Tumoral pulmonary hypertension

“…Plain chest radiography is often normal or shows diffuse reticulonodular opacities, and less often Kerley B lines and pleural effusions [45]. Parenchymal computed tomography (CT) abnormalities (figure 4b) are nonspecific and include centrilobular nodules, ground-glass attenuation, interlobular septal thickening and consolidation [23].…”

Pulmonary tumour thrombotic microangiopathy presented as gastric signet ring cell carcinoma: A case report

“…1 PTTM is strongly associated with carcinomas, especially poorly differentiated signet-ring cancers of the stomach, with a post-mortem prevalence of 17-27%. 5 Other commonly associated malignancies with PTTM include lung, breast, colon, and pancreas. 5 Although the exact pathogenesis of PTTM remains unclear, several proteins have been implicated in its development.…”

“…5 Other commonly associated malignancies with PTTM include lung, breast, colon, and pancreas. 5 Although the exact pathogenesis of PTTM remains unclear, several proteins have been implicated in its development. For example, vascular endothelial growth factor (VEGF) and tissue factor (TF) have been reported to be expressed more frequently in cancer cells leading to PTTM than those with traditional tumour emboli.…”

“…Although a chest CT scan can be helpful, it is insensitive. 4,5 By contrast, pulmonary artery catheterization and wedged pulmonary arterial blood cell sampling has been reported to have high sensitivity and specificity 10 and several studies have used the method successfully to confirm a diagnosis of PTTM. [10][11][12][13] A standard treatment regimen for PTTM has not been established.…”

“…3 The radiological findings on computed tomography (CT) are typically diffuse centrilobular nodular opacities in a tree-in-bud pattern. 4,5 A rapid diagnosis of PTTM is essential because the time from onset of the disease to death is short. 1 We report here on a young woman who presented with dyspnoea, pulmonary hypertension and right heart failure and was initially thought to have signet ring cell carcinoma of the stomach.…”