A reflectance confocal microscope is a machine which is able to examine the upper layers of the skin painlessly and without the need for taking a biopsy. We would like to examine the images taken by the confocal microscope to see if it can help more accurately identify lesions which are worrying rather than a benign mole. We are performing this study in patients in whom we have recommended excising a mole to exclude a cancer. If the results of the study show that the confocal microscope can help more accurately diagnose Melanomas then this would reduce the number of biopsies that are taken that turn out not to be cancerous (ie unnecessary biopsies).

Study Design This is an observational, non-randomised, non-controlled, prospective cohort study to look at the efficacy of in vivo RCM as a diagnostic tool in the diagnosis of MM and LM.

Study Endpoints The hypothesis of this study is that the use of RCM is would reduce the NNE prior to definitive treatment by at least 30% from the current value of approximately 10.

The secondary hypothesis is that the intra- & inter-observer agreement for interpreting the RCM images will have kappa scores 0.6 or greater (indicating good agreement).

Setting and recruitment Patients will be recruited from the outpatient clinics of the Skin Care Network Barnet, and from the outpatient clinics of the Chase Farm and Barnet sites of Royal Free Hospital NHS Foundation Trust.

Participants The number of true negative lesions examined in this study will be 654. It is anticipated that this will result in a total of 661 lesions being recruited. 10% of participants are expected to have more than one lesion sampled.

The result of biopsy for each lesion will not be known until after the lesion has been included in the study. Therefore lesions will be added to the study until the required number of true negatives has been included.

Inclusion Criteria:

1. Age 18 years or older
2. Patient with a pigmented lesion recommended for excision because of suspicion of MM or LM.
3. Patient willing and able to give informed consent

Exclusion Criteria:

1. Recurrent MM or LM
2. Patient on immunosuppresants
3. Patient with significant co-morbidity or skin disease
4. Patient not suitable for diagnostic biopsy
5. Location of lesion unsuitable, inaccessible or impractical for scanning with RCM as determined by investigator

Patients presenting at a skin cancer clinic with a lesion that is clinically suspicious for LM or MM.