Daniela Burguêz*, Giovanni Fabrizzio Pedrotti, Lauro Manoel Etchepare Dornelles, Francisco Consoli Karam, Osvaldo André Serafini
Lipoma arborescens is a rare benign type of synovial membrane tumor. It occurs due to the replacement of synovial tissue by mature adipocytes. It usually affects the knee and is monoarticular. Despite a typical imaging examination, the final diagnosis is only possible with histopathological examination of the lesion. The objective of this article is to present a case diagnosed in a tertiary hospital in Porto Alegre and to highlight this pathology as a differential diagnosis for oncological knee injuries. An 18-year-old female patient had an enlarged left knee for 7 years. We opted for open resection of the lesion with wide synovectomy. One year later, the patient showed improvement in clinical complaints and no signs of tumor recurrence. Although rare, lipoma arborescens should be considered in the differential diagnosis of knee pathologies and open synovectomy is currently the treatment of choice.