Differential Diagnosis for 71y Male with Persistent Cough
Single Most Likely Diagnosis
- Chronic Bronchitis: Given the patient's history of smoking and the presence of a persistent cough for 3 months, chronic bronchitis is a highly likely diagnosis. The CT findings of well-aerated pulmonary parenchyma without significant airspace disease but with a history of smoking support this diagnosis.
Other Likely Diagnoses
- Lung Cancer: Although the CT scan does not show a large mass, the patient's smoking history increases his risk for lung cancer. The minimal left lower lobe soft tissue density pulmonary nodularity could be an early sign of cancer, warranting further investigation.
- Pulmonary Fibrosis: The extensive calcifications in the left hilum and medial left upper lobe suggest prior granulomatous exposure, which could be related to conditions like histoplasmosis or tuberculosis. However, pulmonary fibrosis, especially if related to smoking or other environmental exposures, could also be a consideration given the chronic nature of the cough.
Do Not Miss Diagnoses
- Tuberculosis (TB): Although less likely given the absence of significant airspace disease or lymphadenopathy, TB must be considered, especially with the history of calcifications suggestive of prior granulomatous disease. Missing TB could have significant consequences due to its infectious nature and the need for specific treatment.
- Sarcoidosis: This condition can present with hilar lymphadenopathy and pulmonary nodules, although the CT provided does not specifically mention lymphadenopathy. Sarcoidosis can cause chronic cough and needs to be considered to avoid missing a potentially treatable condition.
Rare Diagnoses
- Histoplasmosis: Given the calcifications suggestive of prior granulomatous exposure, histoplasmosis could be considered, especially if the patient has been exposed to bird or bat droppings. However, this would be less likely without additional symptoms or findings.
- Silicosis or Other Occupational Lung Diseases: Depending on the patient's occupational history, conditions like silicosis could be considered, especially with the presence of calcifications and a chronic cough. However, without specific occupational exposure history, this remains a rare consideration.