Author: Assoc Prof Patrick Emanuel, Dermatopathologist, Auckland, New Zealand, 2013.
Multinucleate cell angiohistiocytoma presents clinically as asymptomatic red-to-brown tumors, with a tendency to confluence.
Histology of multinucleate cell angiohistiocytoma
In multinucleate cell angiohistiocytoma, sections show abundant small dilated blood vessels and fibroplasia, principally in the mid-dermis (figure 1, 2). Higher power shows scattered bizarre cells (figures 3, 4) showing a pale basophiliccytoplasm and several nuclei arranged at the cell periphery (figure 3, arrow). A perivascularinflammatoryinfiltrate may also be seen.
Special studies for multinucleate cell angiohistiocytoma
The multinucleate cells stain with vimentin and factor XIIIa. S100, CD34, and CD31 are negative.
Differential diagnosis of multinucleate cell angiohistiocytoma
Dermatofibroma – Some authors consider multinucleate cell angiohistiocytoma to be a variant of dermatofibroma. Dermatofibromas typically do not display the same degree of vascularity or the characteristic giant cells.