Emperipolesis and S100 expression may be seen in cutaneous xanthogranulomas: A multi‐institutional observation

Cutaneous Rosai‐Dorfman disease (RDD) can be difficult to distinguish from other non‐Langerhans cell histiocytoses, particularly xanthogranuloma (XG). Pathologists use S100 immunoreactivity, abundant plasma cells, and the presence of emperipolesis to distinguish RDD from XG. However, S100 expression has been reported in XG and, in practice, we have occasionally observed emperipolesis in cases that were otherwise clinically and pathologically consistent with XG. We present 10 cases of XG with emperipolesis and variable S100 immunoreactivity. Histologically, 7 cases were most in keeping with XG, and a histologic differential of XG versus RDD was raised in the remaining 3 cases. All 10 cases were clinically consistent with XG. Notably, none of these cases showed abundant plasma cells. Nine cases showed variable S100 immunostaining, ranging from focal/weak expression, to focal/strong, diffuse/moderate, and diffuse/strong expression. Histiocytes in all cases were CD68 positive and CD1a negative. We conclude that emperipolesis and S100 expression in a skin biopsy cannot reliably distinguish XG from cutaneous manifestations of RDD. Clinical correlations are essential, as are histologic clues to a diagnosis of classic XG that include an abundance of foamy mononuclear cells, Touton giant cells, and an absence of pale‐stained histiocytes, abundant plasma cells, fibrosis, or vascular proliferation.     

3DTEE imaging of a descending aorta floating thrombus in a patient with calciphylaxis

We present a case of a 68‐year‐old man with calciphylaxis, who was found to have a floating thrombus in the descending aorta on a transesophageal echocardiogram. The use of 3D echocardiography demonstrated nicely the free motion of the thrombus, emerging from an atherosclerotic plaque in the descending aorta. Anticoagulation was started for thromboembolism prevention.     

Ulnar nerve entrapment in Guyon’s canal caused by a ganglion cyst: two case reports and review of the literature

European Journal of Orthopaedic Surgery & Traumatology - In this article, two cases of ulnar nerve neuropathy in Guyon’s canal caused by a ganglion cyst are reported. A review of the...