AbstractBackgroundBecause a sternal mass is often alarming, it is important to identify the clinical features of benign processes.ProcedureData on clinical presentation, diagnostics, treatment and outcome of pediatric patients presenting with a sternal tumor between 2001 and 2009 were collected from medical records.ResultsAmong the 1,700 children who were referred to our pediatric‐oncology center, 14 presented with a rapidly growing sternal mass. All patients (10 males) were Caucasian and median age was 16 (range: 7–50) months. Reported symptoms were local pain (n = 7) and/or raised body temperature (n = 5). No major preceding traumas were reported. Physical examination revealed solid tumors with a median diameter of 3 (range: 1–4.5) cm in a pre‐sternal/para‐sternal location. Half of the patients showed red/blue discoloration of the skin. On radiology, dumbbell‐shaped lesions extended to the area behind the sternal bone, involving the cartilage, leading to increased distance between ossification centers. Histopathology at diagnosis was available from five patients and showed aspecific chronic or acute inflammation (n = 4) and a reactive osteochondromatous lesion (n = 1). Laboratory infection parameters were not/only slightly raised and microbiologic cultures were negative in all patients. All tumors decreased in size within 1 month, in both patients with and without antibiotics. On physical examination the tumors disappeared within 6 months.ConclusionsThis study reports 14 young children with a rapidly growing sternal mass due to aseptic inflammation, that we named self‐limiting sternal tumor of childhood (SELSTOC). To prevent invasive diagnostic interventions and unnecessary treatment, we advocate a wait‐and‐see approach with close follow‐up in the first weeks. Pediatr Blood Cancer 2010;55:81–84. © 2010 Wiley‐Liss, Inc.