Abstract
INTRODUCTION: Avascular necrosis of the bone is a very common finding in sickle cell disease (SCD). The malignant transformation of a pre-existing bone infarct is extremely rare, only few cases has been reported related to different etiologies one of which is SCD. PRESENTATION OF CASE: 40 years old male, known to have SCD, he presented as a case of avascular necrosis of the left proximal femur. Upon further investigations the lesion has transformed into undifferentiated pleomorphic sarcoma also known as Malignant Fibrous Histiocytoma (MFH). DISCUSSION: The exact mechanism of the malignant transformation of bone infarcts is not fully understood and yet to be investigated. Few cases were reported in literature of similar malignant transformation of a pre-exciting bone infarct and only one was linked to SCD. CONCLUSION: In reporting this case we hope that further cases worldwide will be reported. A high index of suspicion should be present when encountering bone infarct lesion with an unusual course.