Abstract
A 66-year-old male with a black macule on his right sole was admitted to our clinic. The clinical features of the black macule were asymmetrical, irregular contour, dark diffuse palpable without elevation or ulcer formation. He was palpated; no inguinal or popleteal lymph nodes were noticed. No biopsies were performed, and pre-operative lymph-scintigraphy with 99mTc was performed to detect sentinel lymph nodes. Immediately before the resection of the tumor, a sentinel lymph node was excised under a guide of local injection of 2% patent blue around the tumor. Though the primary lesion was only 0.8 mm in thickness, equivalent to Clark's level II, the sentinel lymph node showed metastatic tumor cells. Further lymph node dissection and general CT examination did not reveal any other metastasis. Because such a thin melanoma, less than 1 mm, caused local lymphatic metastasis, invasive melanoma in any thickness should undergo a sentinel lymph node biopsy. [Skin Cancer (Japan) 2007; 22: 77-80]
