[Melanoma within tattoos: Two cases and a systematic literature review]

There have been reports of malignant melanoma arising within tattoos. However, there is no clear relationship between tattoos and the development of cutaneous malignancies. We report two new cases of melanoma and provide a review of cases of melanoma reported in the medical literature.

Case No. 1: a 61-year-old patient consulted following the appearance one year ago of a nodular lesion measuring 4.5×3cm on a blue and red tattoo on his back. Complete excision of the lesion with histological analysis revealed an ulcerated nodular melanoma with a Breslow depth of 7mm. No secondary sites were found. Case No. 2: a 39-year-old patient with a blue tattoo on his left arm consulted following the appearance of a pigmented lesion a few months earlier. Surgical excision was immediately performed, confirming the diagnosis of SSM, with a Breslow depth of 0.9mm. There was no sign of relapse 9 years later.

In our systematic review we noted 34 cases of melanoma occurring in tattoos. There was a high male prevalence (90.3%) and a relatively young mean age (45.9 years). Most tattoos were monochrome (71.0%). The average time between tattooing and onset of melanoma was 13.2 years. The most common sites of melanoma were the upper limbs (53.1%) and trunk (34.4%). Mean tumor size was 11.6mm. Histologic examination revealed 2 cases of melanoma in situ, and in 13 cases, the Breslow depth was 1mm or less. In 5 cases, macroscopic or microscopic lymph node metastasis (sentinel lymph node) was found at diagnosis, and in one case, in transit skin metastases were also observed at the time of diagnosis. We discuss the hypothetical pathogenic role of tattoos in melanoma.