Follow-up of patients with aspirated breast cysts is necessary.

A review was conducted of 401 women who presented with breast lumps that proved to be cysts by yielding fluid on aspiration. The aim was to determine the proportion of patients with cancers that masqueraded as cysts and to establish whether short-term follow-up was necessary. After the first visit, six patients had biopsies because of a residual mass or a bloodstained aspirate. Of these patients, two were found to have cancer. After the follow-up visit, 20 further biopsies were carried out for presence of a mass, bloodstained fluid, or recurrent fluid, and two more cancers were diagnosed. Of the four patients with malignancy, only one had an intracystic carcinoma, two had necrotic grade 3 ductal carcinomas, and one had a malignant phyllode tumor. These findings underline the value of a single return visit after cyst aspiration.