The cutting edge of skin lesions in general practice and pathology

Abstract

The mainstay of this thesis was to assess the role of the GPs in detecting and managing skin lesions and the role of pathology in this process and to assess how GPs, dermatologists and pathologists can cooperate to make certain that each patient receives optimal and cost-effective medical care.

There are large differences between GPs with regard to the number of skin excisions performed and use of histopathological investigation. Performing more skin excision does not lower the numbers of referrals to surgeons and dermatologists. Overall, only about 60% of skin excisions are submitted for histopathological investigation, while the majority of GPs submit <50% of the removed tissue. GPs that have been surprised more often by pathology results submit more often. The likelihood of malignancy appears to be the most important reason for sending skin excisions for pathology investigation, and more than the clinical diagnosis. The total yield of (pre-)malignancies in skin excisions submitted for pathology is between 5% and 10%, most of them unexpected, including serious malignancies. Unexpected malignancies in skin excisions performed by GPs occur across all clinical diagnosis categories, and about 2% of clinically 100% benign lesions are malignant. Although malignancy rate clearly increases with age, malignancies are also found in younger patients. About 2% of subcutaneous excisions are malignant, all unsuspected. GPs seem to particularly miss nodular type melanomas. Lowering the number of unnecessary excisions is a more fruitful approach to cost saving than omitting histopathology of excised lesions. It seems very important to let patients undress when they present with a pigmented skin lesions to investigate the overall pattern of the skin and to detect the “ugly duck” if present. The relatively large number of patients in The Netherlands with metastatic melanoma with unknown primary suggests that part of these are caused by missing the diagnosis of the primary skin lesion due to of cauterization/freezing or not submitting excised tissue for histopathology. Dermatoscopy may be a valuable addition for the diagnostic and management strategy of pigmented skin lesions by GPs.