AUTHOR=Müller Kilian , Berking Carola , Voskens Caroline , Heppt Markus V. , Heinzerling Lucie , Koch Elias A. T. , Kramer Rafaela , Merkel Susanne , Schuler-Thurner Beatrice , Schellerer Vera , Steeb Theresa , Wessely Anja , Erdmann Michael 

TITLE=Conventional and three-dimensional photography as a tool to map distribution patterns of in-transit melanoma metastases on the lower extremity

JOURNAL=Frontiers in Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1089013

DOI=10.3389/fmed.2023.1089013

ISSN=2296-858X

ABSTRACT=Background: In melanoma, in-transit metastases characteristically occur at the lower extremity along lymphatic vessels.
Objectives: The objective of this study was to evaluate conventional or three-dimensional photography as a tool to analyze in-transit metastasis pattern of melanoma of the lower extremity. In addition we assessed risk factors for the development of in-transit metastases in cutaneous melanoma. 
Methods: In this retrospective, monocentric study first we compared the clinical data of all evaluable patients with in-transit metastases of melanoma on the lower extremity (n=94) with melanoma patients without recurrence of disease (n=288). In addition, based on conventional (n=24) and three dimensional photography (n=22), we defined the specific distribution patterns of the in-transit metastases on the lower extremity. 
Results: Using a multivariate analysis we identified nodular melanoma, tumor thickness, and ulceration as independent risk factors to develop in-transit metastases ITM (n=94).
In patients with melanoma on the lower leg (n=31), in-transit metastases preferentially developed along anatomically predefined lymphatic pathways. In contrast when analyzing in-transit metastases of melanoma on the foot (n=15) no clear pattern could be visualized. In addition, no difference in distance between in-transit metastases and primary melanoma on the foot compared versus the lower leg were observed using three dimensional photography (n=22).
Conclusions: A risk-adapted follow-up of melanoma patients to detect in-transit metastases can be applied by knowledge of the specific lymphatic drainage of the lower extremity. Our current analysis suggests a more complex lymphatic drainage of the foot.