Abstract
Ewing's sarcoma/primitive neuroectodermal tumour (ES/PNET) is a rare tumour usually detected in young individuals and uncommonly found within the breast tissue. In this case report, we examined a 46-year-old patient, who developed a lump on her breast and was later diagnosed with ES/PNET. Clinical presentation, age at development and radiological findings were of interest and were discussed. Diagnosis of the tumour was confirmed using various immunohistochemical studies and the presence of a translocation, t(11;22). A literature review of this rare condition was also included.