Umbilical endometriosis: report of a case and its dermoscopic features.

Cutaneous endometriosis is a rare manifestation of endometriosis, representing 0.5% to 1% of all endometriosis cases. It can be divided into primary and secondary, when appearing spontaneously or after a surgical procedure, when it is mostly found on surgical scar tissue. Some etiologies were proposed, but none of them could entirely explain the appearance of the tumor. Differential diagnosis includes melanoma, metastatic nodule, keloid and pyogenic granuloma. Dermoscopic features are not yet well established, but there are some characteristics that suggest the diagnosis. Treatment is surgical in larger sized lesions. Malignization can occur. The screening for endometriosis is mandatory by means of gynecologic, imaging and marked-tumor evaluation. We report a case of primary umbilical endometriosis and discuss its dermoscopic aspects.