RESUMO
A 2-year-old boy was seen with a painful swelling of the left costochondral junction. Laboratory examination revealed no signs of infection. Echography and CT-scan revealed swelling of the 4th and 5th costochondral junction and the pectoral muscle. Tietze's syndrome was suspected and a wait-and-see policy was decided on. During follow-up, the symptoms gradually decreased. Ten weeks after the onset of symptoms there was only a slight, painless swelling with normal ultrasound findings. Tietze's syndrome is defined as a benign, painful, non-suppurative and localised swelling of the costosternal, costochondral or sternoclavicular joints with spontaneous regression of symptoms. It is typically described in adults but appears in children and infants as well. Recognition of this syndrome and knowledge of its favourable outcome can prevent invasive diagnostic procedures.