Hemosiderotic fibrohistiocytic lipomatous lesion: early pleomorphic hyalinizing angiectatic tumor?

Hemosiderotic fibrohistiocytic lipomatous lesion (HFLL) and early pleomorphic hyalinizing angiectatic tumor (PHAT) are characterized histologically by an admixture of fat, moderately cellular fascicles of hemosiderin-laden spindle cells growing in a perivascular, periadipocytic and septal pattern, as well as the presence of macrophages and chronic inflammatory cells. In contrast to a suggested reactive nature of HFLL, PHAT is regarded as a non-metastasizing tumor of uncertain lineage in the recent World Health Organization classification of soft tissue tumors. Reported herein is the case of a 47-year-old woman with an unencapsulated and irregularly circumscribed recurring lesion in the ankle/foot region that developed following ankle distortion and that fulfills histological criteria for both HFLL and early PHAT. In summary, the present case suggests a reactive over-neoplastic nature of HFLL and confirms profound histological similarities with early PHAT. Until more data become available on the biological potential of HFLL/early PHAT, radical surgical excision and follow up of the patient remains the best treatment option.