Glomeruloid hemangioma. A distinctive cutaneous lesion of multicentric Castleman's disease associated with POEMS syndrome.

A histologically distinctive cutaneous hemangioma occurring in two patients with biopsy-proven multicentric Castleman's disease associated with POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes) syndrome are reported. The lesions were multiple, and appeared as red to purple papules over the trunk and proximal limbs. Microscopically, ecstatic dermal vascular spaces were seen filled with aggregates of capillaries, resulting in structures reminiscent of renal glomeruli. Interspersed between the blood-filled capillary loops were plump "stromal" cells possessing clear vacuoles and periodic acid-schiff-positive eosinophilic globules. These cells had the immunohistochemical profile of endothelial cells (positivity for factor VIII-related antigen, and negativity for leukocyte common antigen, macrophage marker, and muscle-specific actin), and probably represented immature elements that had accumulated immunoglobulins and other proteinaceous material from the circulation. Because vascular lesions may appear before the full-blown POEMS syndrome develops, we suggest careful evaluation and follow-up of all patients presenting with glomeruloid hemangioma or cherry-type capillary hemangioma with focal glomeruloid features for potential development of this syndrome.