Fulminant Pulmonary Hypertension Due to Pulmonary Lymphangitic Carcinomatosis and Tumor Embolism From Occult Pulmonary Adenocarcinoma.

Pulmonary lymphangitic carcinomatosis (PLC) and pulmonary tumor embolism (PTE) are rare manifestations of metastatic malignancy that may mimic more common causes of dyspnea and pulmonary hypertension, often leading to delayed diagnosis. Both conditions are associated with poor prognosis and may present with rapidly progressive right ventricular failure. A 45-year-old female lifelong non-smoker with no significant past medical history presented with a two-week history of cough, pleuritic chest pain, and worsening fatigue. CT pulmonary angiography was negative for central macrovascular pulmonary embolism but demonstrated interlobular septal thickening, ground-glass opacities, pulmonary nodules, and vertebral lesions. Initial echocardiography showed mild to moderate pulmonary hypertension with preserved right ventricular function. Despite supportive management, the patient experienced rapid clinical deterioration, progressing to severe pulmonary hypertension, right ventricular failure, cardiogenic shock, and pulseless electrical activity arrest. Post-mortem examination revealed invasive pulmonary adenocarcinoma with extensive lymphovascular invasion and metastatic disease, consistent with PLC and PTE. This case emphasizes the need to take into account PLC and PTE in patients with rapidly progressive pulmonary hypertension despite negative pulmonary embolism imaging. Recognition of subtle radiographic clues may facilitate earlier diagnosis, although prognosis remains poor once right ventricular failure develops.