Expression of p57KIP2 in infantile hemangioma

Aim: To compare the expression of p57 as indirect marker of genomic imprinting of CDKN1C in a series of infantile hemangiomas (IH) of patients with and without Beckwith - Wiedemann syndrome. Materials and methods: Cases of mammary, salivary gland, liver ( one each), and placental ( 2 cases) capillary hemangiomas all with histological features akin to IH as well as typical examples of cutaneous ( 8 cases) IH were analyzed by immunohistochemistry with antibody against p57(KIP2). This protein is the product of CDKN1C an imprinted, maternally expressed gene. The liver hemangioma and both chorioangiomas were from patients with Beckwith - Wiedemann syndrome. Positive and negative controls included normal placental tissue and complete hydatidiform mole, respectively. Positive staining was localized to nuclei. Results: Endothelial cells from the skin, breast and salivary gland hemangiomas were p57(KIP2) positive while chorioangiomas and liver IH presenting in patients with Beckwith - Wiedemann syndrome were negative. Controls reacted appropriately. Conclusions: Endothelial cells of IH not associated with BWS normally express p57(KIP2) while chorioangiomas and IH of the liver associated with BWS do not. These results suggest that the BWS IH may result from dysregulation of the cell cycle.