Insights on pulmonary tumor thrombotic microangiopathy: a seven-patient case series.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a disease process wherein tumor cells are thought to embolize to the pulmonary circulation causing pulmonary hypertension (PH) and death from right heart failure. Presented herein are clinical, laboratory, radiographic, and histologic features across seven cases of PTTM. Highlighted in this publication are also involvement of pulmonary venules and clinical features distinguishing PTTM from clinical mimics. We conducted a retrospective chart review of seven cases of PTTM from hospitals in the greater Los Angeles metropolitan area. Patients in this series exhibited: symptoms of cough and progressive dyspnea; PH and/or heart failure on physical exam; laboratory abnormalities of anemia, thrombocytopenia, elevated LDH, and elevated D-dimer; chest computed tomography (CT) showing diffuse septal thickening, mediastinal and hilar lymphadenopathy and nodules; elevated pulmonary artery pressures on transthoracic echocardiogram and/or right heart catheterization; and presence of malignancy. Tumor emboli and fibrocellular intimal proliferation were seen in pulmonary arterioles, while two patients had pulmonary venopathy. PTTM is a devastating disease occurring in patients with metastatic carcinoma. An early diagnosis is challenging. Understanding the clinical presentation of PTTM and distinguishing PTTM from clinical mimics may help achieve an early diagnosis and allow time for initiation of treatment.

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

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.