Immunophenotypic characterization of the cell infiltrate in five cases of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease)

Solitary Intracranial Rosai-Dorfman Disease: Case Report and Literature Review

“…The entity usually shows an isointense signal on T1-weighted MRI and a hyperintense signal on T2-weighted imaging, 29 Immunohistochemical studies in RDD have revealed positivity for S100 protein and CD68 (KP1) but negativity for CD1a. 25,27,30,31 The presence of chronic inflammatory infiltrate, emperipolesis and positive S100 staining is consistent with RDD. It can be differentiated ultrastructurally from Langerhans cell histiocytosis by the absence of Birbeck granules 32 -35 and negativity for CD1a.…”

“…It can be differentiated ultrastructurally from Langerhans cell histiocytosis by the absence of Birbeck granules 32 -35 and negativity for CD1a. 30,31,36 Because it is a benign condition, the firstline treatment for RDD of the CNS is currently surgical resection. Although debulking might be curative, it has been reported that 14% of cases recur or relapse after surgery.…”

Review of Rosai-Dorfman Disease: New Insights into the Pathogenesis of This Rare Disorder

“…Histopathologically, the picture of RDD is quite distinct with a dilated lymph node sinus with polymorphous infiltrates composed of histiocytes, small-sized mononuclear cells, polyclonal lymphocytes, and plasma cells [12,13,14,15]. Histiocytes are large and foamy and contain abundant cytoplasm, either granular or vacuolated, with medium-to-large vesicular nuclei in a well-delineated round-to-oval shape.…”

“…Atypia is unusual, as it is with mitosis [15]. Intrasinusoidal lymphocytes are mainly mature T cells with a CD4 + phenotype over the CD8 + subset [15]. Another feature of great diagnostic importance is the viable intact lymphocytes entrapped within the cytoplasm of most histiocytes, a phenomenon named as lymphocytophagocytosis or emperipolesis (Fig.…”

“…The single but distinct central nucleolus is eosinophilic and small in most nuclei. Atypia is unusual, as it is with mitosis [15]. Intrasinusoidal lymphocytes are mainly mature T cells with a CD4 + phenotype over the CD8 + subset [15].…”