Extract
Sinus histiocytosis with massive lymphadenopathy, also known as
Rosai-Dorfman disease, is a rare condition of marrow hemopoietic stem-cell
origin. Most patients present with lymphatic involvement, whereas less than
one-third of cases are extranodal
presentations1.
Extranodal cases present as space-occupying lesions, and it is necessary to
exclude malignant tumor as a diagnosis. Only about 5% of the extranodal cases
involve bone1, and
these are often associated with extraosseous manifestations. Primary solitary
osseous involvement is very uncommon. We report a case of Rosai-Dorfman
disease with primary solitary involvement of the triquetrum without
lymphadenopathy. This is an uncommon cause of an osseous lesion in the short
bones of the hands and feet and, to our knowledge, it has not been described
in the triquetrum previously.