Differential diagnosis of pediatric solitary solid lung mass

• Granuloma from histoplasmosis or tuberculosis
• Metastasis
• Round pneumonia
• Esophageal duplication / bronchogenic cyst
• Inflammatory myofibroblastic tumor
• Pleuropulmonary blastoma

Approach to the differential diagnosis of a solitary solid lung mass:

• Solitary solid lung masses are often noted incidentally on CXR
• In the appropriate clinical setting of infection, round pneumonia may be presumed and treated. A followup CXR should be obtained 2 weeks after end of treatment to verify resolution of the mass. If the mass has not resolved, chest CT is indicated
• If a lung mass is calcified it can be presumed to be a granuloma, most likely from histoplasmosis or tuberculosis
• If a patient has a malignancy and a new lung mass, a short interval followup CT can be obtained in 2 weeks to exclude infection as the cause of the mass
• Pleuropulmonary blastoma is the lung mass that most commonly fills the entire hemithorax