Pulmonary Tumor Thrombotic Microangiopathy Leading to the Discovery of Underlying Gastric Adenocarcinoma

Document Type

Conference Proceeding

Publication Date

5-21-2024

Publication Title

Am J Respir Crit Care Med

Abstract

Introduction- Pulmonary tumor thrombotic microangiopathy (PTTM), coined in 1989, is a rare fatal complication of gastric carcinoma involving widespread tumor emboli, thrombi, reactive pulmonary vascular changes, pulmonary hypertension and is almost always diagnosed post-mortem. There is limited literature on pathophysiology and effective management. Description- A 45-year-old man with remote smoking and recent vaping developed progressively worsening shortness of breath over 2 months. Initial imaging was concerning for interstitial lung disease, was started on prednisone taper and developed a new oxygen requirement of 2-4 L. He then developed sudden onset bilateral hip pain with mobility impairment causing him to present to the emergency department. Workup was remarkable for new bicytopenia with hemoglobin 7 g/dL, platelet count 34000/μL, D-dimer >20 ug/mL FEU, LDH 1035 IU/L, CT abdomen and pelvis concerning for primary gastric malignancy, numerous predominantly sclerotic lesions throughout the osseous pelvis, proximal femurs, sacrum and lumbar spine, peritoneal involvement, diffuse pulmonary ground-glass opacities with interlobular septal thickening and fissural nodularity with upper lobe predominance and widespread lymphadenopathy suspicious for lymphangitic metastatic spread. He rapidly decompensated requiring ICU admission for heated high-flow nasal cannula. Echocardiogram could not determine pulmonary artery pressure. He developed diplopia and dizziness, MRI brain showed 10x20 mm left middle cranial fossa enhancing mass with edema, was started on highdose steroid taper. A CT-guided cervical lymph node biopsy revealed gastric adenocarcinoma with signet ring morphology, HER2 IHC 2+, FISH negative, PD-L1 CPS < 1, microsatellite stable. He started dose-reduced FOLFOX chemotherapy while in the ICU, eventually discharged and tolerated chemotherapy and radiation to gastric and brain lesions, with disease stability, and eventual resolution of hypoxia. Discussion- This presentation is likely due to aggressive gastric carcinoma with pulmonary lymphangitic spread, initially mistaken for interstitial lung disease. A clinical picture of right heart failure may have been masked by initiating early diuresis. Case series describe patterns of cough, dyspnea, right heart failure, anemia, thrombocytopenia, elevated LDH and D-dimer, CT with diffuse septal thickening, mediastinal and hilar lymphadenopathy and nodules, elevated pulmonary artery pressures and presence of malignancy and immunohistochemical expression of tissue and vascular endothelial growth factors. PTTM can lead to pulmonary stenosis and manifest as right heart failure leading to the diagnosis of underlying gastric carcinoma. Acute hypoxic respiratory failure in an otherwise healthy male with a cancer diagnosis should raise suspicion for PTTM. Further research is warranted to better understand this lethal condition for earlier diagnosis and timely management.

Volume

209

Issue

9

First Page

A7076

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