Sentinel lymph node biopsies in patients with malignant melanoma — qualifying principles and histopathological assessment (2017)

Abstract

In 1999, the World Health Organisation (WHO) stated that sentinel lymph node biopsy should be the standard of management for those patients with melanomas without clinical signs of metastases to the regional lymph nodes. This procedure should include preoperative and intraoperative lymphoscintigraphy, combined with staining. Sentinel lymph node biopsies should be performed after excision biopsy of the melanoma and simultaneously with radical excision of the remaining scar after melanoma excision biopsy. Whenever sentinel lymph node(s) are found tumo­ur occupied, metastases are most likely to be located in one or more lymph nodes that were first occupied along lymphatic drainage from the primary focal point of the cancer. Detecting even single melanoma cells in the sentinel lymph node is usually used to determine the stage of the disseminating cancer and radically changes prognoses and further therapeutic decisions. Guidelines on lymph nodes examined during melanoma have been established by the College of American Pathologists (CAP), the European Society of Pathology (ESP) and the Polish Society of Pathologists in 2013. If melanoma metastases are found in sentinel lymph node(s) then: the number of lymph nodes should be specified as well as the number of those with metastases; microscopic features of sentinel lymph node(s) metastases should be defined as follows: the largest metastasis/ /metastases size, their location (subcapsular, intraparenchymal, mixed or extended), signs of possible infiltration and crossing the node capsule, penetration into adipose tissue and vasculature involvement.