Anal melanoma in the era of sentinel lymph node mapping: a diagnostic and therapeutic challenge

Abstract

Melanoma of the anal canal is a rare malignancy that often has an atypical presentation. Locoregional metastases, which are often present at the initial presentation, may occur in both groin and pelvic lymph nodes, but the utility of lymph node dissection remains unknown. We explored the possibility of applying the technique of sentinel lymph node (SLN) mapping to anal melanoma. SLN mapping was performed in 2 patients with anal melanoma. Radioactive tracer and blue dye were injected around the lesions. The SLN was identified pre-operatively by lymphoscintigraphy, and at surgery with a hand-held gamma detector and by visualization of the dye. The SLN was identified in both patients, only in the groin in one and only in the presacral region in the other. One patient had a wide local excision of the anal lesion with house flap anoplasty, while the other had abdominoperineal resection with total mesorectal excision. There were no SLN metastases in either patient. The technique of SLN mapping and biopsy is easily adapted to surgery for malignant melanoma of the anus. SLN mapping and biopsy could aid in planning surgical strategy, but definitive conclusions may only be reached after more experience has been acquired.

Melanoma of the Anal Canal: A Case Series

“…Few case reports on the use of SLNM in anal melanoma have been reported. 30 Although SLNM and biopsy in anal melanoma has not yet become a standard of care, it is technically feasible as reported in these case reports. Long-term follow-up of the impact of the possible finding of micrometastases is needed.…”

Anorectal melanoma

“…If anorectal melanoma metastasizes to inguinal or mesenteric lymph nodes, SLNB is feasible. [30][31][32] While there are case reports to show this is possible, it is not yet used on a broad scale. However, the impact this could have and the logistics are yet to be established.…”

Melanoma colorrectal: revisión de dos formas diferentes de presentación

“…La evidencia sobre la detección del ganglio centinela en el caso del melanoma anorrectal es mucho menor que en el caso de otros tumores habiéndose descrito en algunas publicaciones 27,28 . El interés de la detección del ganglio centinela viene definido por la posibilidad de realizar una linfadenectomía completa en caso de que se detecte invasión metastásica en él.…”