Jemds.com Case Report J Evolution Med Dent Sci / eISSN - 2278-4802, pISSN - 2278-4748 / Vol. 11 / Issue 03 / February 2022 Page 445 Sinus Histiocytosis with Massive Lymphadenopathy (Rosai Dorfman Disease) - Diagnosis of a Masquerader on Fine Needle Aspiration Cytology of Lymph Node - A Case Report Seema Umarji 1 , Sheela Praveen 2 , Umashankar S. 3 , Rajesh S. 4 , Ashwin Kulkarni 5 1, 2 Consultant Pathologist, Prima Diagnostics, Yelahanka, Bangalore, Karnataka, India. 3 Consultant Radiologist, Prima Diagnostics, Yelahanka, Bangalore, Karnataka, India. 4 Consultant Physician, Prima Diagnostics, Yelahanka, Bangalore, Karnataka, India. 5 Department of Medicine, Ramaiah Medical College, Bangalore, Karnataka, India. Sinus histiocytosis with massive lymphadenopathy (SMHL) was first described by Destombes in 1965. 1 Rosai and Dorfman later identified this disorder as a clinicopathologic entity and labelled it as sinus histiocytosis with massive lymphadenopathy and it since then came to be also known as Rosai Dorfman disease. 2,3 Rosai and Dorfman described SHML as massive lymphadenopathy affecting mostly cervical group of lymph nodes in young black children. 2,3 Later various reviews involving larger number of cases showed a much broader spectrum of the entity. 4 The age of patients varied from new born to eighth decade of life. A worldwide distribution with male predominance was noted. The most common site of involvement is lymph node followed by extra-nodal sites such as head and neck region, soft tissue, breast, gastrointestinal tract, central nervous system and bones. 5 We report an interesting case of a young male who presented with low grade fever for 2 weeks and cervical lymphadenopathy which was clinically suggestive of tuberculous; however, on fine needle aspiration cytology (FNAC) it was diagnosed as Rosai Dorfman disease. A 21years old male patient presented to the FNAC clinic with low grade fever for 2 weeks, neck swelling of two months duration which was progressively increasing in size. There was no history of cough or weight loss. He gave history of positive Mantoux test in childhood for which he had received and completed a course of anti- tubercular therapy. On examination, he was moderately built and nourished. Multiple cervical lymph nodes were palpable more on the left side of the neck, the largest one measuring approximately 2.0 x 2.0 centimetre which were firm in consistency, non- tender, discrete. No other regional lymph nodes were palpable. Systemic examination was normal. Corresponding Author: Dr. Ashwin Kulkarni, Ramaiah Medical College, Bangalore, Karnataka, India. E-mail: drashwinkulkarni@yahoo.in DOI: 10.14260/jemds/2022/88 How to Cite This Article: Umarji S, Praveen S, Umashankar S, et al. Sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman disease) -diagnosis of a masquerader on fine needle aspiration cytology of lymph node- a case report. J Evolution Med Dent Sci 2022;11(03):445-447, DOI: 10.14260/jemds/2022/88 Submission 19-01-2021, Peer Review 25-01-2021, Acceptance 19-02-2021, Published 25-02-2022. Copyright © 2022 Seema Umarji et al. This is an open access article distributed under Creative Commons Attribution License [Attribution 4.0 International (CC BY 4.0)] INTRODUCTION PRESENTATION OF CASE