Lymphoscintigraphy in cutaneous melanoma: usual and unexpected pathways of lymphatic drainage

Lymphoscintigraphy is a commonly utilised imaging technique for mapping the lymphatic system and evaluating the lymphatic drainage, particularly in the context of malignancies. This modality plays a critical role in identifying sentinel lymph nodes (SLNs), which are an important tool for accurate cancer staging, ultimately guiding clinical management decisions. Among the Food and Drug Administration (FDA)-approved radiotracers used for SLNs mapping, 99mTc-tilmanocept (Lymphoseek®) has gained clinical acceptance due to its receptor-targeted mechanism and favourable imaging characteristics, although its adoption varies by region and practice setting. In this paper, we discuss lymphoscintigraphy and its techniques, with a focus on cases of cutaneous malignant melanoma that illustrate typical and atypical lymphatic drainage patterns observed on lymphoscintigraphic imaging, particularly in the context of sentinel lymph node mapping.