Visceral lesions in an unusual case of sézary's syndrome

A 29‐year‐old woman with long‐standing thrombocytopenia due to megakaryocytic hypoplasia developed features of Sézary's syndrome associated with arthropathy and signs of peripheral vascular occlusion. She died 14 months later. At necropsy, cellular infiltrations including lymphocytes, histiocytes, plasma cells, and atypical mononuclear cells were found in the walls of small arteries and parenchyma of visceral organs as well as in the skin. The infiltrations had led to fibrosis and focal parenchymal damage which resembled that seen in experimental and iatrogenic graft‐vs.‐host reactions. In places there was a transition between these mixed cellular infiltrations and uniformly lymphocytic infiltrations with histologic features of a lymphoma.