Black sentinel lymph node and 'scary stickers'

Area of Science:

• Oncology
• Dermatology
• Surgical Pathology

Background:

• Sentinel lymph node biopsy (SLN) is a critical staging procedure for primary cutaneous melanoma.
• Accurate SLN identification relies on radiotracer and dye visualization.
• Cutaneous tattoos are increasingly common and may interfere with SLN assessment.

Observation:

• A young adult with cutaneous melanoma presented with two radio-nucleotide tracer-active sentinel lymph nodes.
• These nodes were black-stained, consistent with the patient's tattoos.
• Histopathology confirmed the tracer activity was due to tattoo pigment, not melanoma metastasis.

Findings:

• The presence of tattoo pigment in SLNs can lead to false positives.
• This finding averted the need for a potentially unnecessary elective regional node dissection.
• The case highlights a potential diagnostic pitfall in melanoma staging.

Implications:

• Obtaining a detailed history of tattooing and tattoo removal is essential for all melanoma patients undergoing SLN biopsy.
• Proper staging of SLN biopsy and completion node dissection is vital for accurate diagnosis and treatment planning.
• This emphasizes the importance of integrating patient history with imaging and pathology for optimal oncologic care.