Sinus histiocytosis with massive lymphadenopathy. Is the lymph node enlargement always massive?

Abstract

Sinus histiocytosis with massive lymphadenopathy (SHML) is a benign proliferating histiocytic disorder, predominantly of lymph nodes with extra-nodal involvement in some cases. It is a self-limiting disease and has a good prognosis; however some patients need steroid therapy. Therein lays a need to differentiate it from other lympho proliferative disorders of poorer prognosis. Clinically, it is suspected only when there is a significant lymph node enlargement in younger age group as the term signifies. Recently, we came across a case where a middle-aged female presented with a subtle swelling in submental region, clinically suspected of reactive or tubercular etiology. However on fine needle aspiration cytology, the smears showed many histiocytes, some of them showing lymphocytes and plasma cells in their cytoplasm, a morphological feature called as "emperipolesis" classically seen in SHML. The present case is reported because of unusual clinical presentation and possibly the need for a revision of existing terminology.