Intraosseous Rosai-Dorfman disease diagnosed by touch imprint cytology evaluation: A case series

Case of Generalized Tumor-Type Rosai-Dorfman Disease With Sarcoidosis-Like Histological Features and IgG4-Positive Plasma Cells

ABSTRACT

Rosai-Dorfman disease (RDD, also known as sinus histiocytosis with massive lymphadenopathy) is a rare and benign non-Langerhans cell histiocytosis. Skin biopsy usually shows nodular or diffuse dermatitis. Rosai-Dorfman cells (RDD cells) and emperipolesis are the key to diagnosis. RDD cells express S-100 antigen, CD68, CD163, α1-antitrypsin, α1-antichymotrypsin, and ham-56, whereas Langerhans cell markers such as CD1a and langerin are negative. We presented a case of a 55-year-old man with varying sizes of many dark red nodules and lumps over the face, trunk, and limbs for approximately 1 year but without systemic involvement. The results of the laboratory evaluations were notable for an increased level of serum IL-6 and serum IgG4. Histopathological examination showed a diffused dense nodular infiltration of "nude" epithelioid histiocytes with infiltration of minimal lymphocytes and plasm cells around the epithelioid nodules. Immunohistochemistry identified nodular histiocytes being stained strongly positive for S-100 and CD68 but negative for CD1a. Plasma cells showed focally positive for IgG, IgG4, and CD38 and with a ratio of IgG4/IgG >40%. Considering these findings, we believe that our case meets the diagnostic description of "cutaneous Rosai-Dorfman disease" and is, therefore, a rare case with clinical features of multiple tumor-like nodules, sarcoidosis-like histological features, and immunohistochemistry of IgG4-positive plasma cells.

Fine-needle aspiration specimens of 3 cases of intra-abdominal Rosai-Dorfman disease with comprehensive review of the literature

INTRODUCTION

Rosai-Dorfman disease (RDD) is a rare usually self-limited non-Langerhans cell histiocytosis of unknown etiology. Nodal and extranodal RDD appear to represent distinct conditions with different molecular alterations and prognosis. They also pose different diagnostic challenges on biopsies and fine-needle aspiration (FNA) cytology. The aim of this study was to report on 3 cases of intra-abdominal RDD and perform an extensive review of the literature on FNA findings of RDD.

MATERIALS AND METHODS

We reviewed FNA specimens from cases diagnosed histologically or cytologically as RDD during the past 10 years. We searched the PubMed and Google Scholar databases for cases of RDD sampled by FNA.

RESULTS

We identified 3 cases of intra-abdominal RDD, involving the kidney, periportal lymph node, and pancreas. FNA of the latter was hypocellular with fibrosis and was nondiagnostic. FNA of the first 2 yielded hypercellular smears that were diagnosed as RDD due to the identification of emperipolesis occurring in large uni- or binucleated histiocytes with large nuclei, fine chromatin, and prominent nucleoli in smears and cell-block sections. Immunohistochemistry showed positive staining for S100 and CD68 and negative staining for CD1a. The large histiocytes with emperipolesis were more difficult to identify histologically and their demonstration required immunohistochemical stains.

CONCLUSION

Our experience and an extensive review of the literature suggest that extranodal RDD can be diagnosed on FNA, and that the recognition of histiocytes with emperipolesis may be less challenging cytologically than histologically. The fibrosis frequently seen in extranodal RDD may lead to nondiagnostic aspirates, however.