Tattoo pigment mimicking metastatic malignant melanoma in an axillary sentinel lymph node

The case of a 37-year-old man with a Clarkes level III, Breslow thickness 1.2 mm superficial spreading melanoma of his forearm is described. Intraoperatively, a black-pigmented ipsilateral axillary sentinel lymph node, highly suspicious for metastatic disease, was harvested. The patient had a faded tattoo in the vicinity of the malignant melanoma. Histological examination of the lymph node demonstrated normal lymphoid tissue and the presence of pigmented macrophages due to tattoo ink. Metastatic malignant melanoma was ruled out. The importance of histological confirmation of an enlarged pigmented node before complete dissection of the regional lymph nodes is discussed. The importance of recording the presence of decorative tattoos is stressed as the tattoo pigment may clinically mimic metastatic disease in those with malignant melanoma undergoing sentinel lymph node biopsy.