Figure 1
Gross sectioning and embedding of sentinel nodes. The primary objective of the gross management of sentinel nodes is assuring that all macrometastases larger than 2.0 mm are identified microscopically by assuring no slice is thicker than 2.0 mm before embedding in paraffin. When nodes are serially sectioned, special care must be taken to place the sections into the embedding cassette in a manner that eliminates more than 2.0 mm of unexamined tissue. Histology technicians are taught to embed and cut the surface that is placed down in the tissue-processing cassette. Dashed lines represent the surface placed down in the cassette. (a and b) Central serial sections are placed in the cassette so that nonopposing surfaces are examined microscopically. One of the end sections will be an opposing surface. (c) This shows incorrect grossing and embedding preparation. The central serial sections were placed in the cassette so that neither surface containing the micrometastasis was evaluated microscopically.
