Differential Diagnosis for a Stable 4 mm Fissural Nodule
- Single most likely diagnosis
- Pulmonary hamartoma: This is the most common benign lung tumor and can present as a small, stable nodule, often with popcorn calcification. The stability of the nodule over time and its small size are consistent with a hamartoma.
- Other Likely diagnoses
- Granuloma: A small, stable granuloma from a previous infection (such as histoplasmosis) could present similarly. The lack of growth or change suggests a benign process.
- Bronchogenic cyst: Although less common, a small bronchogenic cyst could appear as a stable nodule, especially if it is not communicating with the airway.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Small cell lung cancer or other aggressive lung cancers: Although less likely given the stability and small size, any lung nodule has the potential to be malignant. Early detection of lung cancer is crucial for treatment outcomes.
- Metastasis: A solitary metastasis from another primary cancer could present as a small nodule. The history of any previous cancers would be important in assessing this possibility.
- Rare diagnoses
- Pulmonary arteriovenous malformation (AVM): A small AVM could appear as a nodule, but this would be less common and might have characteristic imaging features such as feeding and draining vessels.
- Intrapulmonary lymph node: Although rare, an intrapulmonary lymph node could present as a small nodule, especially if it is not associated with other lymphadenopathy or systemic disease.