Differential Diagnosis for Elevated D-Dimer and Lung Nodule
Single Most Likely Diagnosis
- Pulmonary Embolism (PE): The combination of an elevated D-dimer and a lung nodule could indicate a pulmonary embolism, especially if the nodule is a pulmonary infarct or a Hampton's hump, which is a wedge-shaped, pleural-based consolidation. The elevated D-dimer suggests thrombosis, and PE is a common cause of elevated D-dimer levels.
Other Likely Diagnoses
- Lung Cancer with Thrombosis: Lung cancer can cause both a lung nodule and an elevated D-dimer due to associated thrombosis, such as a pulmonary embolism or deep vein thrombosis (Trousseau’s syndrome).
- Infectious Processes (e.g., Pneumonia, Abscess): Certain infections can cause both a lung nodule and an elevated D-dimer due to inflammation and thrombosis.
- Inflammatory Conditions (e.g., Sarcoidosis, Vasculitis): Conditions like sarcoidosis or vasculitis can cause lung nodules and elevate D-dimer levels due to inflammation.
Do Not Miss Diagnoses
- Pulmonary Arteriovenous Malformation (PAVM): Although less common, PAVMs can cause a lung nodule and may be associated with an elevated D-dimer if there is thrombosis or embolism.
- Septic Pulmonary Emboli: These can occur in the setting of right-sided endocarditis or other infections and can present with lung nodules and elevated D-dimer levels.
Rare Diagnoses
- Lymphangitic Carcinomatosis: A rare condition where cancer spreads to the lymphatic vessels of the lungs, potentially causing a lung nodule and an elevated D-dimer.
- Wegener's Granulomatosis (Granulomatosis with Polyangiitis): A form of vasculitis that can cause lung nodules and may be associated with an elevated D-dimer due to inflammation and thrombosis.
- Chronic Thromboembolic Pulmonary Hypertension (CTEPH): A rare condition that can cause lung nodules and elevate D-dimer levels due to chronic thromboembolism.