A case of primary pulmonary follicular dendritic cell sarcoma

Abstract

Here, we report a 66-year-old woman who presented with an irregular and lobulated pulmonary mass in the apical segment of the right superior lobe with an enlarged mediastinal lymph node. Abdominal computed tomography (CT), brain magnetic resonance imaging, and fluorine-18 fluorodeoxyglucose positron emission tomography/CT scans showed no extrapulmonary distant metastases. The patient underwent surgical sleeve resection of the right superior lobe with systematic hilar and mediastinal lymph node dissection. Post-operative histopathology, including hematoxylin and eosin staining, immunohistochemistry, and Epstein–Barr virus in situ hybridization, suggested primary pulmonary follicular dendritic cell sarcoma (FDCS). A follow-up plain chest CT indicated recurrence with multiple metastases of the liver, ribs, and mediastinal lymph nodes 1 year after surgery. The patient declined further therapy and was lost follow-up. In this case, FDCS located in the lung was unusual and rare. Corresponding imaging and histopathological features have enhanced our understanding of this disease. Meanwhile, it is necessary to include this tumor as a differential diagnosis of lung tumors and pay particular attention to the possibility of post-operative recurrence and metastasis. Moreover, considering the heterogeneity of FDCS, it is essential to identify the biological or imaging features that can reflect or predict the high risk of tumor recurrence and metastasis. A corresponding post-operative examination is also necessary to determine if any lesions remain.