Pleomorphic Hyalinizing Angiectatic Tumor: Immunohistochemical Study with Review of Literature.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is relatively a new entity that was described first in 1996. Although it is often confused with neurilemmoma and low grade malignant fibrous histiocytoma, it is considered to be a distinctive neoplasm because of certain unique microscopic and immunohistochemical findings. It is a low grade, slowly growing tumor that recurs after surgical removal in about a third of all cases. It is not known to metastasize. In this review, we have immunohistochemically analyzed a case of gluteal soft tissue tumor in a 22-year-old woman using CD 34, CD 68, CD 99, S100 and desmin. Classical histological features and positivity for only CD 34 helped in establishing the diagnosis as PHAT. We have reviewed the available literature.