Pulmonary sclerosing pneumocytoma - approaching a solitary pulmonary nodule and the limitations of risk prediction models.

Our case is an asymptomatic, non-smoking, East Asian woman in her 40s presenting with a solitary pulmonary nodule (SPN). On imaging, the 1.7 cm solid SPN located in the left upper lobe, was rounded in morphology and moderately fluorodeoxyglucose avid. The clinical pretest probability of malignancy assessed by risk prediction models such as Brock (19.1%), Mayo Clinic (56.2%) and Herder (51.4%) was discordant. She underwent a percutaneous CT-guided needle biopsy, establishing a diagnosis of pulmonary sclerosing pneumocytoma (PSP). PSP is a rare benign lung neoplasm with indolent growth characteristics that has been described predominantly in non-smoking women. Our case illustrates the limitations of applying existing risk prediction models in Asia where the epidemiology and biology of lung cancer differ significantly from the Caucasian derivation cohorts. Additionally, the risk models do not account for tuberculosis, which is endemic in Asia and can mimic malignancy. Non-surgical lung biopsy remains useful in minimising unnecessary thoracotomy.

A lung mass: Not the usual suspect, but not above suspicion.

Lipoid pneumonia is an entity that is not commonly thought of when faced with opacities on the chest radiograph. The radiological changes of lipoid pneumonia can mimic pneumonia or malignancy. Due to this mimicry, it is commonly missed and alternative diagnoses should always be considered and ruled out when suspecting lipoid pneumonia. Although majority of lipoid pneumonias occur due to exogenous ingestion of oil, endogenous factors such as bronchial obstruction and pulmonary alveolar proteinosis can also result in this condition. The emphasis of this case is on the approach to and treatment of lipoid pneumonia, including its association with malignancy.