Local lymph node micrometastasis in a patient with negative sentinel lymph node biopsies after lymphatic mapping with wide local excision of primary melanoma on the head/neck area.

Sentinel lymph node biopsy is widely accepted as a staging procedure for patients with cutaneous melanoma who are at risk for metastases. The complex lymphatic drainage pattern on the head and neck makes sentinel lymph node mapping more challenging compared with other sites. Here, we report a patient who underwent reexcision of the primary tumor site with lymphatic mapping on the right posterior auricular area. Four sentinel nodes were negative for melanoma metastasis; however, step sectioning of the wide local excision of the primary tumor site revealed a small lymph node with histopathologic detection of micrometastasis. Our findings highlight the importance of a careful histopathologic approach that may have prognostic impact on outcome and survival.