Malignant melanoma disguised in a tattoo.

Abstract

A 76-year-old man with a medical history of malignant melanoma and non-melanoma skin cancer presented to the dermatologist for his 6-monthly skin examination. He was of English descent with type II skin and was raised in Queensland. He reported no lesions of concern. The examination revealed a 2-cm diameter pigmented lesion in his tattoo on his right upper arm (Fig. 1a). It was irregular in shape and symmetry and of variegated colour. He was unaware of this lesion at the time of the examination and prior to his tattoo, which was over 20 years old. There was no documented record of this pigmented lesion in his previous dermatology consultations. Dermoscopy was difficult (Fig. 1b), however, the features of asymmetry, globular structures, grey veil and an atypical network suggested a melanoma. An elliptical excision of the pigmented lesion was performed. The histopathology revealed macroscopically an irregular brown macule measuring 20 × 8 mm. Microscopically there was a melanoma in situ (Fig. 1c). Tattoos are not an established risk factor for melanoma. The English literature reports 16 cases of malignant melanoma developing in tattoos, and herein we present the 17th case. The pathogenesis of melanoma developing at tattoo sites is unknown and the association may be fortuitous. Further research is required to investigate the possibility of an association between melanocytic proliferation and tattoos. Other neoplastic lesions such as basal cell carcinoma and squamous cell carcinoma have been reported in association with tattoos. Some tattoo reactions, including pseudocarcinomatous or keratoacanthoma-like reactions, can be difficult to differentiate from true cutaneous malignancies. This case demonstrates that tattoo ink may camouflage the clinical signs of a melanoma. The assessment of pigmented lesions among a tattoo is difficult for patients on a macroscopic level, for dermatologists at a clinical and dermoscopic level, and for histopathologists at a microscopic level. The patient himself had not noticed this lesion in his tattoo despite a presumed increase in his awareness because of his personal history of melanoma. It is uncertain whether this was a truly new lesion or one that had been observed but thought benign, or not been detected on previous consultations. This emphasises the masking effect of tattoo ink, even in lesions this size, to patients and potentially to clinicians. The lesion may have been detected earlier if there was no tattoo. The dermatologist’s dermoscopy assessment was difficult as the tattoo ink interrupted and masked some of the signs for interpretation. The tattoo ink colour may additionally influence the diagnostic difficulty. The difficulties experienced in this patient have the potential for delayed or incorrect diagnoses or misdiagnoses, which can ultimately result in poorer patient outcomes. The increased prevalence of tattoos makes this an important complication, especially in Australia, with the highest incidence of melanoma worldwide. Approximately one in seven Australians has a tattoo, with the most popular age group from 20–39 years. This cohort is also least likely to

DOI: 10.1111/ajd.12219

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Cite this paper

@article{Anthony2015MalignantMD, title={Malignant melanoma disguised in a tattoo.}, author={Eleni P Anthony and Amanda M Godbolt and Fiona Tang and Erin Kelly McMeniman}, journal={The Australasian journal of dermatology}, year={2015}, volume={56 3}, pages={232-3} }