Tattoo pigment in sentinel lymph nodes: a mimicker of metastatic malignant melanoma

Tattoo pigment in the sentinel lymph nodes of melanoma patients represents a clinical challenge. If a tattoo is present in the area of the primary melanoma, the draining lymph nodes are likely to contain tattoo pigment, as well as being the site for metastatic deposits of melanoma. We describe a case report involving an elderly Caucasian male diagnosed with a Clark level-4 nodular malignant melanoma, wherein intraoperatively we encounter a darkly pigmented lymph node highly suspicious for metastatic disease. The patient had a tattoo in the vicinity of the malignant melanoma The specimen is sent for histological examination and is found to contain pigmented macrophages, but metastatic malignant melanoma is not identified. Histological confirmation of an enlarged pigmented node is essential before radical surgery is performed.