Differential Diagnosis for Peripheral Mass with Poorly Defined Borders in the Right Upper Lung Field
- Single Most Likely Diagnosis
- Lung cancer: This is the most likely diagnosis due to the presence of a peripheral mass with poorly defined borders, which is a common presentation for lung tumors, especially non-small cell lung cancer and small cell lung cancer. The location in the upper lobe is also typical for lung cancer.
- Other Likely Diagnoses
- Infection (e.g., pneumonia or abscess): Although less likely than lung cancer, an infectious process could present with a mass-like lesion, especially if it's a complicated pneumonia or an abscess. The borders might appear poorly defined due to inflammation.
- Inflammatory pseudotumor (also known as inflammatory myofibroblastic tumor): This rare benign tumor can mimic lung cancer on imaging but tends to have a more favorable prognosis.
- Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can involve the lung and present as a mass, though this is less common than other manifestations.
- Do Not Miss Diagnoses
- Pulmonary embolism with infarction: Although typically presenting with wedge-shaped or rounded consolidations, a pulmonary embolism can occasionally mimic a mass, especially if there's associated hemorrhage or infarction. Missing this diagnosis could be fatal.
- Tuberculosis: Especially in endemic areas, tuberculosis can present in various forms, including as a mass-like lesion in the lung periphery. It's crucial not to miss this diagnosis due to its public health implications and the need for specific treatment.
- Rare Diagnoses
- Hamartoma: A benign lung tumor that could present as a well-defined mass but occasionally might have poorly defined borders due to surrounding inflammation or other factors.
- Metastasis: While metastases to the lung are common, a single peripheral mass with poorly defined borders is less typical for metastatic disease, which usually presents with multiple, well-defined nodules.
- Sarcoidosis: This systemic disease can involve the lungs and present with nodular lesions, but these are usually multiple and bilateral, making it a less likely diagnosis for a single peripheral mass.