Pleomorphic hyalinizing angiectatic tumor arising in the thigh: A case report.

Pleomorphic hyalinizing angiectatic tumors (PHATs) are rare non-metastasizing tumors of uncertain lineage. The current study presents a case of PHAT arising in the thigh of a 68-year-old female and examines the clinicopathological characteristics of the tumor. Magnetic resonance imaging (MRI) revealed an intramuscular mass located in the adductor longus. The tumor was surrounded by lipomatous tumor. Wide resectioning was performed for the internal tumor, whereas intralesional resectioning was performed for the external tumor. Histopathologically, the internal lesion was diagnosed as a PHAT and the external lesion was diagnosed as an hemosiderotic fibrolipomatous lesion (HFLL). No recurrence or metastases were identified during the 6-year follow-up period. As the adipose tissue surrounding the PHAT resembled a HFLL, therefore, the association between 'early PHAT' and HFLL is discussed. Although PHATs may represent low-grade sarcomas, HFLLs may be benign tumors.