Follicular dendritic cell sarcoma (a case report)

Relevance. Follicular dendritic cell sarcoma (FDCS) is an extremely rare tumor originating from dendritic cells of lymphoid follicles. It most commonly arises from lymph nodes, but may originate from a variety of extranodal sites. Case description. We present the rare case of a 42 year-old-man with extranodal FDCS of the lung. The patient underwent right extended pneumonectomy with resection of the pericardium and mediastinal lymph node dissection. We analyzed clinical, morphological and immunohistochemical characteristics and assessed Vimentin, CD23, CD35, CD68, CD21, CD1a, Ki67 expressions in the tumor cells. Immunohistochemical study showed that the tumor cells were positive for Vimentin, CD23, and CD35. The CD68 expression was observed in most tumor cells, and the CD 21 expression was less abundant in tumor cells. The proliferative activity of Ki67 was about 30 % of the tumor cells. There was no CD1a expression. Thus, the diagnosis of FDCS of the lung with the involvement of 2 broncho-pulmonary lymph nodes was made. Conclusion. Considering the following evidence: extremely rare malignant neoplasm involving the lung; slow-growing indolent disease; difficulty in preoperative diagnosis; extended surgery with resection of the main bronchus and vessels through the pericardial cavity; unfavorable risk factors (tumor is more than 6 cm, involvement of bronchopulmonary lymph nodes), adjuvant chemoradiotherapy was recommended.