Successful Mapping of Sentinel Lymph Nodes with Technetium-99m Phytate in Two Cases with Cutaneous Malignancies Arising on a Toe

We herein report the successful usage of preoperative lymphoscintigraphy using technetium-99 m-phytate for two cases of cutaneous malignancies arising in a toe. Case 1 was a 67-year-old man with subungual melanoma on his right big toe. Although no sentinel nodes were detected by lymphoscintigraphy using technetium-99 m tin colloid, technetium-99 m. phytate successfully demonstrated two sentinel nodes in the right inguinal region. Case 2 was a 61-year-old man with subungual squamous cell carcinoma on his right big toe. Lymphoscintigraphy using technetium-99 m phytate demonstrated three sentinel nodes in the right inguinal region. The sentinel nodes imaged by lymphoscintigraphy were further identified using intraoperative blue dye and then were successfully excised in both cases, Because phytate is smaller in size than tin colloid, technetium-99 m phytate is thus considered to be potentially useful for the detection of sentinel nodes.