Recent eLetters

Dear Sir,

As a dermatologist involved in skin cancer management I read with interest your article on mole checks on the high street and the concerns raised by the All Party Parliamentary Group on Skin (APPGS). I gave evidence to the APPGS and shared their concerns regarding the lack of training in skin cancer diagnosis, for staff performing the clinical examination in such clinics. The high street mole screening clinics were invited to give evidence of their governance standards by the APPGS in 2008 and were criticised in the report for failing to do so. To highlight the potential prevalence of misdiagnosis on the high street I would like to give evidence about two cases seen within a month, to support the concerns raised by the APPGS.

Case 1. A 46 year old lady presented requesting excision of a lesion on her chin. She had recently visited a high street mole screening clinic, where she was diagnosed with a suspected basal cell carcinoma (BCC). A clinical and dermoscopic image had been taken and was sent for an overseas tele-dermoscopic opinion. She received a phone call and a report 24 hours later which confirmed a lesion suspicious for a BCC, and advised to have surgery. Having prepared herself for surgery she attended my clinic where a benign intradermal naevus was confirmed and she was reassured that no surgery was required. This case does illustrate the limitations of tele- dermoscopy when the referring ‘clinician’ is not medically trained, which therefore gave false suspicion on a very benign lesion. Additionally teledermoscopy for pink lesions has been shown to be less accurate than face-to face diagnosis even for experienced dermatologists. 1

Case 2. A 32 year old man with a previous history of BCC sought skin cancer screening as he had moved to the UK. He had a 12 month history of a persistent pink macule on the right side of his neck at the edge of the scar of his BCC excision. He was screened by a non-medically qualified practitioner and a SIAScopic image was taken and sent for a remote (within the UK) expert diagnosis. He received a report 3 weeks later stating that all was well. The pink area remained and he sought a second opinion. On examination he had an obvious clinical recurrence of his BCC. This was completely excised and confirmed on histology. There were a number of errors in his management. Firstly the history of previous BCC excision at this site would make a diagnosis of recurrence highly suspicious on clinical history alone. Secondly too much weight was placed upon a SIAScopic image alone and not in the context of the history, leading to misdiagnosis and mismanagement. The blood vessel patterns of BCCs can be non-specific, from simple erythema to the typical arborizing telangiectasia; the pressure applied for image acquisition may also impair vascular structures. Thus the importance of an expert making the clinical diagnosis face to face of pink lesions in patients at risk for skin cancer should not be underestimated. 1 Additionally SIAScopy, a diagnostic tool not routinely used by dermatologists, has been independently shown to be less accurate than dermoscopy, which is the standard diagnostic tool for skin lesion diagnosis. 2-3A large study, assessing the role of SIAScopy as a diagnostic tool in primary care, is due to conclude in 2010.4 However, until the results are available one cannot assume that this technology is validated as a diagnostic test, without the support from evidence of this study. Therefore the use of this technology at the present time is contrary to the UK National Screening Committee recommendations for screening where there should be ‘ a simple, safe, precise and validated screening test’.4

These two cases reflect the potential for misdiagnosis of skin cancer that may occur when commercial organisations and non-experts are involved in skin cancer diagnosis, namely a false positive or a false negative diagnosis. Sadly these two cases may be the tip of the iceberg as I have additional cases and I am aware of other dermatologists having similar experiences, although with an absence of a central database for reporting such activity formal evidence may be lacking. These cases do however support the concerns raised by the APPGS on the standard of diagnosis at these clinics and additionally give evidence towards poor standard of care as illustrated. Further evidence should be sought to answer or dispel the concerns of the APPGS more thoroughly. With the evidence supplied, the continuing expansion of high street clinics offering skin cancer screening is a concern particularly as many such clinics promote themselves to the public as the experts in mole diagnosis and skin cancer screening; the public should be made aware that firstly there is no evidence to support this claim and secondly evidence to the contrary exists.

References 1. Fabbrocini G et al. Telediagnosis and face-to-face diagnosis reliability for melanocytic and non-melanocytic 'pink' lesions. J Eur Acad Dermatol Venereol. 2008 Feb;22(2):229-34

2. Haniffa MA, Lloyd JJ, Lawrence CM. The use of a spectrophotometric intracutaneous analysis device in the real-time diagnosis of melanoma in the setting of a melanoma screening clinic. Br J Dermatol. 2007 Jun;156(6):1350-2 3 Glud M, Gniadecki R, Drzewiecki KT. Spectrophotometric intracutaneous analysis versus dermoscopy for the diagnosis of pigmented skin lesions: prospective, double-blind study in a secondary reference centre. Melanoma Res. 2009 Jun;19(3):176-9 4. MoleMate™ UK Trial: The management of suspicious pigmented lesions in primary care

5. UK National Screening Committee. Criteria for appraising the viability, effectiveness and appropriateness of a screening programme (see www.library.nhs.uk/screening)