Report of an Unusual Case of Hemosiderotic Fibrohistiocytic Lipomatous Tumor with Systematic Review of Clinicopathological Characteristics and Differential Diagnosis

The spectrum of lipomatous lesions ranges from benign to highly malignant disease. Differentiation between these mesenchymal lesions is important for pathologist as well as clinician to indicate prognosis and choose the most appropriate treatment. Hemosiderotic firohistiocytic lipomatous tumor (HFLT) is a rare subtype of lipomatous tumor. The diagnosis is usually based on clinical, histological, and immunohistochemical (IHC) information. We reported a case of 56 years old man with a painful mass in the dorsal aspect of the thigh showing an unusal clinical presentation but a characteristic histological and IHC features. In this article we have retrospectively reviewed the 67 cases of HFLT reported in literature so far along with one case reported at our institution. The review focuses on clinicopathological and histomorphological characteristics of HFLT and the related entities. The hallmark of HFLT and its related lesions is complex admixture of mature adipose tissue, spindle tumor cells with striking deposition of hemosiderin pigment. Even though HFLT shows marked predeliction for the distal extremeties especially the foot/ ankle with a female preponderance, they can occur at uncommon site such as thigh and also in males as seen in our case. Keywords: Pleomorphic hyalinizing angiectatic tumor, Hemosiderotic fibrolipomatous tumor, Myxoinflammatory Fibroblastic Sarcoma, Hemosiderin, Lipoma