Glomeruloid hemangioma

A 64‐year‐old Japanese woman suffering from idiopathic thrombocytopenic purpura was treated with prednisolone. During the course of steroid withdrawal she developed parotid gland enlargement and cervical lymph node swelling with multiple dome‐shaped red papules on her trunk and upper limbs. On admission the patient was found to have numbness of her lower limbs (polyneuropathy), lymph node swelling (organomegaly), high glucose level (endocrinopathy), Bence‐Jones protein‐κ in the urine (M protein) and skin with hyperpigmentation, hypertrichosis and multiple glomeruloid hemangiomas (skin abnormalities), indicating polyneuropathy–organomegaly–endocrinopathy–M‐protein–skin abnormality (POEMS) syndrome. The patient was also found to have peripheral edema, ascites, and pleural effusion. The glomeruloid hemangiomas had intravascular capillary growth, which was composed of conglomerates of capillaries resulting in structures resembling renal glomeruli. Cells within the capillary loops were lined by endothelial cells with scant cytoplasm (CD31 + /CD34 + /CD68 ‐ /CD105 + /UEA‐1 + ) while the outer surfaces of the loops were covered by either swollen endothelial cells containing PAS‐ and immunoglobulin‐positive eosinophilic hyaline globules (CD31 + /CD34 ‐ /CD68 −/+ /CD105 ‐ /UEA‐1 ‐ ) or cells without globules. These two phenotypically different endothelial cells were separated by α‐smooth muscle actin‐positive pericytes. Pericytes and endothelial cells covering the outer surface of the loops were bordered by basement membrane. Biopsy of parotid gland and lymph node indicated Sjögren's syndrome and Castleman's disease of a hyaline‐vascular type, respectively. Resumed prednisolone therapy has been successful, and the patient was left with minimal residual symptoms. Glomeruloid hemangioma is a specific marker of POEMS syndrome and is related to Castleman's disease. Idiopathic thrombocytopenic purpura and Sjögren's syndrome may also be related.