Suspicious skin lesions and their management

To describe the spectrum, diagnosis and management of non pigmented suspicious skin lesions in general practice.

General practitioners recorded all patients initiating consultations for suspicious skin lesions over 6 weeks in a tropical provincial city in Queensland as part of a study to determine the incidence of skin cancer. The spectrum of lesions and outcomes of the examinations and diagnoses are reported. Proportions of correct clinical diagnoses with 95% confidence intervals (CI) were calculated on excised lesions. Options in clinical management according to certainty of diagnosis were compared with chi-square statistics.

Of the 81 eligible GPs 61 (75%) recorded detailed data on 1355 lesions. These included clinical diagnoses of 387 (28.6%) nonmelanoma skin cancers, 836 (61.7%) dysplastic lesions and 132 (9.7%) other benign lesions. 454 (33.5%) lesions were reported as excised or biopsied, 707 (52.2%) were treated without biopsy, 24 (1.8%) were referred to a specialist, 147 (10.9%) were monitored without treatment and 23 (1.6%) had no management specified. For lesions histologically confirmed by local pathologists as malignant (basal cell carcinoma or squamous cell carcinoma), the clinical diagnosis was correct in 69.1% of cases (95% CI 62.5-75.7%). The doctors reported managing 71.2% (95% CI, 65.6-76.7%) of clinically diagnosed BCC and 90.2% (95% CI, 85.6-94.9) of SCC by excision or biopsy. If more certain of the diagnosis of solar keratosis they were likely to treat without obtaining histology and if less certain they were likely to excise or biopsy (p = < 0.0001).

GPs see a spectrum of skin lesions which are of concern to patients. A high proportion of these lesions are clinically benign and are not excised. If a BCC or SCC is suspected or diagnosis is uncertain most lesions are excised or biopsied.