For Arm 1, participants will be identified in clinic as having a suitable symptomatic breast and approached about the study. They will have the study design explained to them and will be informed that they are under no obligation to participate. Arm 1 participants will receive study information that they will be sent home with and informed that they will be approached via a telephone call in 2-3 days (or the closest working day to that date) to enquire if they would like to schedule an appointment for the study visit. If so, this will be scheduled to occur around 7 days from the date of the phone call.

For Arm 2, participants will be identified in clinic as having a suitable symptomatic breast and approached about the study. They will have the study design explained to them and will be informed that they are under no obligation to participate. Arm 2 participants will receive study information and as much time as possible to consider their involvement with the study (at least 1 hour). If the patient agrees to participate, they will be scheduled to have their MARIA scans at a time that suits their commitments that day.

This arm also includes the 2b group, who can optionally consent to a dielectric constant reading of their routinely-aspirated cyst fluid before this is disposed of as per usual site process.

The MARIA breast imaging system comprises of a scanning unit, housed under a patient bed. The scanning unit houses a hemispherical array, into which varying sizes of insert are fitted to ensure a close fit to the breast. The patient lies prone on the bed with their breast pendulous through an aperture in the bed and the scanning unit is risen to meet the breast. The fit is non-compressing and the scanner does not use ionising radiation.

This will be established from Arm 1 and Arm 2 by scanning the participant between both versions of the MARIA system. As has been investigated in-house with healthy volunteers, the patient will take part in a series of scans that will involve them remaining stationary between scans, and moving between scans. The differences between these images will be analysed, using the known palpable lesion in the breast as a landmark.

This will be established from Arm 1 and Arm 2 by scanning the participant on each separate version of the MARIA system. As has been investigated in-house with healthy volunteers, the patient will take part in a series of scans that will involve them remaining stationary between scans, and moving between scans. The differences between these images will be analysed, using the known palpable lesion in the breast as a landmark.

This will be established from Arm 2b by recording the dielectric constant of the aspirated cyst fluid as soon as possible after aspiration using a dielectric probe. No cysts will be aspirated exclusively for this procedure and fluid will be disposed of as per usual site practice once the recording has taken place. Each cyst fluid sample will have its dielectric constant recorded three times and recorded in the provided software before disposal.

This will be established from Arm 1 and 2 by using a combination of reader results from clinician reads performed by the site team with all available clinical information and blind reads performed in house which will utilise no clinical information.