Localized neoplastic infiltration of the post-sternotomy scar is a rare late healing disorder. We present 2 patients admitted with the suspicion of chronic osteomyelitis, 1 and 5 years after cardiac surgery. Microbiological analyses were negative. Histopathology revealed sternal metastatic lesions of a hepatocellular carcinoma in 1 patient and of an oesophagogastric carcinoma in the other. In cases of an existing primary tumour, which was unknown in both patients, the sternal healing process may promote secondary seeding of tumour cells, due to the inflammatory and hyper-metabolic trauma. Special attention should be therefore payed to atypical post-sternotomy lesions, which require histopathological analysis and imaging assessment.