Cytological Diagnosis of Rosai-Dorfman Disease: A Study of Twelve Cases with Emphasis on Diagnostic Challenges

Abstract

Context: Rosai-Dorfman disease, also known as Sinus histiocytosis with massive lymphadenopathy, is a benign proliferative disorder of histiocytes. It typically affects lymph nodes; however, extranodal disease is being increasingly reported. The latter entity poses exceptional diagnostic challenge clinico-radiologically by forming mass lesions. Fine needle aspiration cytology (FNAC) is the investigation of choice to avoid unnecessary surgery as the majority are self-limiting.

Aims: The objective is to assess the utility of FNAC in the diagnosis of Rosai-Dorfman disease and to highlight the diagnostic difficulties.

Material and methods: The cytology features of 12 cases of Rosai-Dorfman disease were analyzed and correlated with histopathology and immunohistochemistry.

Results: The present study included six nodal and six extranodal Rosai-Dorfman disease. The cytology smears showed a variable number of large histiocytes exhibiting characteristic emperipolesis. Ten cases diagnosed as Rosai-Dorfman disease on cytology were confirmed on histopathology. The presence of granulomas, atypical histiocytes, insignificant emperipolesis, and eosinophil infiltration were the challenges we faced.

Conclusions: FNAC, a simple and cost-effective method with its unique cytology features is the first line of investigation in the diagnosis of Rosai-Dorfman disease.

Keywords: Emperipolesis; Rosai–Dorfman Disease; Sinus Histiocytosis with massive lymphadenopathy; eosinophils; granulomas.

Figure 1

Case 1 a-d. (a) Cytology smear with large histiocytes exhibiting emperipolesis and fragmented neutrophils. (H and E, ×400). (b) Histopathology showing dilated sinuses filled with histiocytes exhibiting emperipolesis. (H and E, ×200). (c) S100 positivity. (×400). (d) CD 68 positivity. (×200). Case 11 e-i, (e and f) Cytology smears showing atypical histiocytes with sparse emperipolesis. (MGG, ×400). (g) Histopathology showing sheets of atypical histiocytes with dense inflammatory infiltrate. (H and E, ×400). (h) CD68 positivity. (×100). (i) S100 positivity. (×200)

Figure 2

Case 5. (a) Cytology smears showing emperipolesis, (H and E, ×200) and (b) Epithelioid cells (H and E, ×400). (c) Histopathology showing histiocytes in dilated sinuses exhibiting emperipolesis. (H and E, ×100). (d) Palisaded granulomas. (H and E, ×200). (e) Emperipolesis. (H and E, ×400). (f) S100 positivity. (×400)

Figure 3

Case 12. H and E stained cytology smears. (a) Very occasional emperipolesis.(×400) (b) Background lymphocytes. (×200). (c) Histopathology. Histiocytes with emperipolesis (×400). (d) S100 positivity (×400)