Mathematical Modelling of Lymph Node Grossing Techniques

The optimal histopathological handling of sentinel lymph nodes remains the subject of debate. There is surprisingly little evidence in support of the manner in which sentinel lymph nodes are grossed. Some authors recommend that a lymph node be sectioned parallel to the long axis of the node, while others recommend that the short axis be used. In either case, the manner in which a sentinel lymph node is grossed determines the cut surface area exposed for histological examination and, in turn, the amount of area examinable for the presence of metastases. In this article, mathematical models of each of these approaches are presented and compared from the perspective of optimization of cut surface area. Computer modelling and simulations are also performed in order to assess how variously sized lymph nodes should be optimally grossed and to assess how frequently an optimal approach improves theoretical tumour focus detection. The results favour the use of the long-axis approach.