Lipoma arborescens of the knee: a rare tumour in a black woman. A case report

A 69 year old Nigerian female presented with a two-year history of intermittent swelling, pain and restriction of movement of the right knee. At open arthrotomy and synovectomy, a huge encapsulated yellowish lobulated fatty mass with frond-like appearance was delivered from the suprapatella and popliteal fossae. It weighed 520g and histology showed clusters of adipocytes with abundant pale cytoplasm as well as clusters of collagen fibres with elongated nuclei and bipolar cytoplasmic processes consistent with lipoma arborescens (LA). There is no recurrence at three years of regular follow-up. On the sheer size of this rare lesion, we have designated LA weighing 500gms or more giant LA. Key words: Knee joint,Giant lipoma arborescens, open synovectomy.