Pleomorphic hyalinizing angiectatic tumor, a rare localization: A case report

Introduction and importance: Pleomorphic hyalinizing angiectatic tumor (PHAT) is a very rare soft tissue tumor with locally aggressive behavior but without metastasizing capacity. The most described localization is in the lower extremities. However, other localizations, such as breast or renal hilium, have already been described. Global literature about this type of tumor is rare. Our objective is to review other rare localizations and the main histopathology findings.Case presentation: We report the case of a 70 year old woman who underwent local surgery to remove a soft tissue mass which had a posterior anatomo-pathological diagnosis of PHAT. Histopathology analyses showed tumor cells proliferation and cellular pleomorphism, associated with hemosiderin pigment deposition and papillary endothelial hyperplasia. Immunohistochemical analyses demonstrated positive expression for CD34 with negative expression of SOX-100 and S-100. Secondary surgery was performed to extend margin resection for the purpose of obtaining negative margins.Clinical discussion: PHAT is a very rare tumor originates in subcutaneous tissues. Although there is no pathognomonic sign, it is frequently found at the microscope hyalinized vasculature, positivity for CD34 or negativity for SOX100 and S-100. Surgery with negative margins is the gold standard treatment. No metastasizing capacity was described for this type of tumor.Conclusion: The aim of this clinical case report - and subsequent literature review - is to update the data about PHAT in order to demonstrate its cytopathological and immunohistochemical characteristics, its differential diagnosis with other soft tissue and malignant tumors and its gold standard treatment.