Figure 1 | Modern Pathology

Figure 1

From: Mutually exclusive recurrent KRAS and MAP2K1 mutations in Rosai–Dorfman disease

Figure 1

KRAS-mutated Rosai–Dorfman disease, soft tissue of trunk (case 3). (a) Medium-power image of soft tissue with aggregates of abnormal emperipoletic histiocytes (× 200). (b) Some areas show dense fibrosis where emperipoletic histiocytes are less obvious to identify (× 400). (c) Immunostain for S-100 is positive in Rosai–Dorfman histiocytes and negative in engulfed lymphocytes (× 400). (d) Immunostain for p-ERK is negative in emperipoletic histiocytes (endothelial cells are positive; × 1000).

Back to article page