[Acetone compression. A fast, standardized method to investigate gastrointestinal lymph nodes]

Lymph node staging is the most important prognostic parameter in malignant gastrointestinal tumors. Manual dissection of adipose tissue is time-consuming and also depends on the experience of the individual examiner. By combining elution with acetone and mechanical compression using simple equipment it was possible to completely embed adipose tissue from 404 surgical specimens (colon 348, stomach 28, greater omentum 14, other location 14) without manual dissection. As a result of the procedure, the weight of the adipose tissue could be reduced by 90%-95%, making full histological examination possible. The colon specimens included an average of 43.8 lymph nodes (14-109) in 14 embedding cassettes (1-38) with a native fat weight of 234.7 g (42.8-820 g). The quality of histological staining, including immunohistochemical and molecular investigations, is of comparable quality to routine work-up. Elution with acetone enables the prompt, standardized and full histological work-up of adipose tissue without manual dissection. Moreover, additional costs are low. The number of lymph nodes required by medical associations was attained in all cases and often exceeded. This method was successfully used in other organs (greater omentum, breast).