P F Penas | PubMed Health

PubMed2003

Diagnostic and neural analysis of skin cancer (DANAOS). A multicentre study for collection and computer-aided analysis of data from pigmented skin lesions using digital dermoscopy.

BACKGROUND: Early detection of melanomas by means of diverse screening campaigns is an important step towards a reduction in mortality. Computer-aided analysis of digital images obtained by dermoscopy has been reported to be an accurate, practical and time-saving tool for the evaluation of pigmented skin lesions (PSLs). A prototype for the computer-aided diagnosis of PSLs using artificial neural networks (NNs) has recently been developed: diagnostic and neural analysis of skin cancer (DANAOS). OBJECTIVES: To demonstrate the accuracy of PSL diagnosis by the DANAOS expert system, a multicentre study on a diverse multinational population was conducted. METHODS: A calibrated camera system was developed and used to collect images of PSLs in a multicentre study in 13 dermatology centres in nine European countries. The dataset was used to train an NN expert system for the computer-aided diagnosis of melanoma. We analysed different aspects of the data collection and its influence on the performance of the expert system. The NN expert system was trained with a dataset of 2218 dermoscopic images of PSLs. RESULTS: The resulting expert system showed a performance similar to that of dermatologists as published in the literature. The performance depended on the size and quality of the database and its selection. CONCLUSIONS: The need for a large database, the usefulness of multicentre data collection, as well as the benefit of a representative collection of cases from clinical practice, were demonstrated in this trial. Images that were difficult to classify using the NN expert system were not identical to those found difficult to classify by clinicians. We suggest therefore that the combination of clinician and computer may potentially increase the accuracy of PSL diagnosis. This may result in improved detection of melanoma and a reduction in unnecessary excisions.

Adult↗

PubMed1997

Perforating granuloma annulare.

BACKGROUND: Perforating granuloma annulare (PGA) is considered an histologic subtype of granuloma annulare (GA) and it is described as a very rare disease, usually of children, affecting the dorsum of the hands. Mechanisms leading to perforation are unknown. Our experience suggested a different clinical presentation, so we decided to review our patients and the cases published. METHODS: We present six cases of PGA and review 52 PGA cases reported in the literature. Data regarding sex, age, time of evolution of disease, clinical features, laboratory findings, treatment, and follow-up were collected. The significance level was determined by the chi 2 or Student t test when appropriate. RESULTS: The prevalence of PGA could be up to 5% of GA. Pustular-like lesions can be found in 26% of cases, and scars in 37%; papular, umbilicated, and crusted lesions being the most common finding. While PGA appears as a single lesion in only 9% of cases, and half of the patients are older than 30 years. In GA 50% of cases present as a single lesion and 80% of patients are younger than 30 years. CONCLUSIONS: PGA is different to GA not only histologically but also clinically. It is a disseminated disease, affecting both children and adults, which is characterized by the presence of multiple papules, most of them umbilicated and/or crusted, and characteristically pustular lesions and scars. Histology suggests that the superficial localization of the necrobiotic granuloma leads to the epidermal perforation. Treatment is disappointing.

Adult↗