Melanoma diagnosis at a specialist dermatology practice without the use of photographic surveillance

Abstract

Background/Objective: Photographic aides are increasingly used in melanoma surveillance. We report melanoma characteristics detected using traditional surveillance without photographic technologies. Methods: Retrospective study of melanomas diagnosed by three dermatologists at a private dermatology practice over 7 years. Patients underwent full skin examinations with dermoscopy and suspect lesions were excised or biopsied. Total body photography (TBP) and serial digital dermoscopic imaging (SDDI) were not used. Patient demographics, melanoma subtype and thickness, location, biopsy technique and keratinocyte cancers diagnosed at the same visit were recorded. Ratio of in situ to invasive melanomas was calculated. Melanoma risk factors were recorded for 69 randomly-selected patients. Results: 492 patients were diagnosed with 615 melanomas during 579 visits. 505 (82%) were in situ (in situ to invasive ratio of 4.6:1). Of the invasive melanomas, 85.5% had a Breslow thickness <0.8 mm, 10 (9.1%) 0.8–1 mm and 6 (5.5%) >1 mm. 43.3% of in situ melanomas were lentiginous or lentigo maligna and 41.6% were superficial spreading melanomas (SSM). Of invasive melanomas, 24.3% were lentigo maligna melanoma and 59.5% were SSM. 48.4% of melanomas were diagnosed by shave procedures. Where risk factors were known, 25% were very-high-risk and 43% had a history of melanoma. Keratinocyte carcinoma was diagnosed by biopsy at 26.1% of visits. Studies using TBP and/or SDDI report in situ to invasive ratios of 0.59:1 to 2.17:1. Conclusion: Tradiational melanoma surveillance with immediate biopsy of suspect lesions results in high in situ to invasive ratios. Studies using photographic surveillance show lower ratios of in situ to invasive disease.