Background: The umbilicus is a fibrous remnant located in the centre of the abdomen. Various entities may be encountered in this special anatomical location; however, little is known about their dermoscopic presentation. The aim of this study was to provide a comprehensive summary of existing evidence on dermoscopic features of umbilical lesions. Methods: Studies assessing dermoscopic images of umbilical lesions were included in this study. No age, ethnicity or skin phototype restrictions were applied. Papers assessing lesions outside of the umbilical area, lacking dermoscopic images and/or dermoscopic description and not related to the topic were excluded. Embase, Medline and Cochrane Library were searched from inception to the end of May 2023. The Joanna Briggs Institute critical appraisal tools were used to evaluate the risk of bias of the selected studies. The quality and the level of evidence of included studies were assessed according to the Oxford 2011 Levels of Evidence. Thirty-four studies reporting a total of 39 lesions met the inclusion criteria and were included in qualitative analysis. Results: A qualitative synthesis of the following entities was performed: melanoma, nevi, basal cell carcinoma, fibroepithelioma of Pinkus, Sister Mary Joseph nodule, mycosis fungoides, dermatofibroma, endometriosis, epidermal cyst, granuloma, intravascular papillary endothelial hyperplasia, lichen planus, omphalolith, seborrheic keratosis, and syringoma. Conclusions: Dermoscopy is a non-invasive technique that may be useful in the differential diagnosis of umbilical lesions. The main limitations of this study were lack of a high level of evidence in the studies and the lack of uniformity in applied dermoscopic terminology between included studies.
Keywords: Sister Mary Joseph nodule; dermatoscopy; dermoscopy; endometriosis; melanoma; navel; nevus; umbilicus.