Extraarticular features are usually found in rheumatological diseases sometimes with no correlation with the disease's activity in that moment. Lymphoedema is one of these manifestations and it's defined as a tissue fluid accumulation with gradual onset of swelling of a limb. Because it is an unusual finding, the physiopatological explanation of this feature is still difficult to understand. We describe a case report of lymphoedema on left upper arm, in a patient with systemic juvenile arthritis, with no identified cause and with no associated systemic signs or symptoms.