Rosai-Dorfman Disease of the Pericardium Accompanied by Monoclonal Gammopathy: A Case Report with CT and PET Imaging Findings

Abstract

Rosai-Dorfman disease (RDD) is an uncommon proliferative histiocytic disorder of unknown etiology typically presenting as massive lymphadenopathy, and in some cases, with extranodal involvement. However, serous membranes are rarely involved in extranodal RDDs, and reports regarding pericardial involvement are scarce. Herein, we report a case of extranodal RDD manifesting as diffuse pericardial thickening and effusion in a 79-year-old man with monoclonal gammopathy. The patient complained of dyspnea, hence chest CT and PET scans were performed. They showed irregular thickening of the pericardium with a marked increase in metabolic activity. Pericardial biopsy showed the characteristic S100-positive and CD68-positive histiocytes exhibiting emperipolesis. The disease progressively evolved to bilateral pleural thickening with effusion of the pericardium, and finally led to death even with corticosteroid treatment. Although exceedingly rare, this case demonstrates the importance of RDD in the differential diagnosis of effusion in serous cavities based on imaging findings.

Keywords: Computed Tomography; Monoclonal Gammopathy; Pericardial Effusion; Pericardium; Rosai-Dorfman Disease.

Fig. 1. A 79-year-old man with Rosai-Dorfman disease of the pericardium.

A. The anteroposterior chest radiograph shows a globular enlargement of the cardiac shadow indicating pericardial effusion. B. A mediastinal window image of chest CT shows a moderate volume of pericardial effusion, diffuse enhancing pericardial thickening, and a mild degree of bilateral pleural effusion. C. LN enlargement is not seen in the thoracic inlet and mediastinum. D. ¹⁸F-fluorodeoxyglucose PET scan reveals irregular thickening of the pericardium with a significant increase in metabolic activity. E. Chest CT scan obtained after 2 months shows no obvious remission of the pericardial thickening and aggravated bilateral pleural effusions with subtle pleural thickening despite intravenous injection of dexamethasone. F. Under the light microscope, low power view (left upper) shows histiocytic aggregation (arrow) in the thickened pericardium with fibrosis and hemorrhage. The high-power view (right upper) shows a large histiocyte (arrow) with engulfed lymphocyte and plasma cell, known as emperipolesis. On immunohistochemistry, the histiocytes are positive for S100 protein (left lower) and CD68 (right lower), as evidenced by their brown staining. H&E = hematoxylin and eosin