The exploding tumour on breast magnetic resonance imaging: an infected skin comedo.

A 61-year-old woman with a histologically proven invasive lobular carcinoma entered a clinical trial, which involved repeat magnetic resonance imaging (MRI). The protocol of the repeated MRI described a T4 breast cancer with involvement of the skin (Fig 1). There were only 17 days between the first and second MRI and during this short time it appeared that there had been rapid disease progression. On the initial MRI, a skin comedo could be seen in the left breast close to the tumour. The patient had squeezed the skin comedo, which had become infected. The second MRI captured the infected skin comedo, which had the appearance of an extensive breast cancer with skin involvement. The patient could be mismanaged if the clinician does not correlate the clinical findings with the radiological findings.