Inking in Surgical Pathology: Does the Method Matter? A Procedural Analysis of a Spectrum of Colours

Proper identification of surgical margins along with margin status holds utmost importance in histopathology. Inking margins is one way. India ink has long been used but it can ink only one margin. On other hand acrylic colours, available in variety of colours can be used for inking multiple margins along with many more advantages. The present study was undertaken to analyse acrylic colours and Indian ink for inking surgical margins via three different methods for optimum results.

Thirteen acrylic colours along with India ink were evaluated via three different methods on radical specimens of breast and colon after preliminary requisites of grossing were completed. In Method 1, coloured inks were applied to an overnight formalin fixed specimen and representative sections were taken. In Method 2, the specimen was inked and kept for overnight fixation. The specimen was sampled following day. In Method 3, the specimen was inked and kept for overnight fixation. The following day, it was re-coloured with the same colours as of the previous day and subsequently sections were taken. Coloured inks were assessed on different parameters for their performance as surgical ink and given scores.

Acrylic shades #04, #22, #06, #01, #02 and India ink had very good to excellent score on microscopy in all three methods. Shades #64, #18, #09, #23 had poor microscopic visibility in all three methods. Shade #09 showed loss of colour and the shade #23 showed penetration into deeper tissues on microscopy. Results were best with Method 3 followed by Method 1 and 2, respectively.

Acrylic colours have more advantages compared to India ink. Method 3 is recommended for inking. Few acrylic shades meet the criteria of surgical inks in all three methods.