Pulmonary sclerosing pneumocytoma with lymph node metastasis and high FDG uptake in PET/CT: a rare case report and literature review.

Pulmonary sclerosing pneumocytoma (PSP) was first reported by Liebow and Hubbell (1956). It was initially called pulmonary sclerosing hemangioma (PSH) because it was thought to be derived from endothelial cells with rich vascularity. However, the 2015 World Health Organization Classification of Lung Tumors removed the term "sclerosing hemangioma," since these tumors lack vascular origin (Travis et al., 2015), and the renamed tumor was considered a rare and benign lung tumor. However, several reports have described PSP with lymph node metastasis (Soo et al., 2017). Thus, PSP is not always benign and has the potential to metastasize. PSP shows varying levels of F-fluorodeoxy-glucose (FDG) accumulation, with the maximum standardized uptake value (SUV) ranging from the background value to 6.4 (Chen et al., 2012; Jiang et al., 2018). Therefore, it is easily misdiagnosed as other malignant tumors and is often removed surgically or treated improperly. Here, we present a rare case of PSP in a young woman with lymph node metastasis, a high FDG uptake on positron emission tomography/computed tomography (PET/CT) scan, and an SUV of 6.1.