Entirevolume Serial Histological Examination for

Authors: Masaki Hata Junji Machi Jonathan Mamou Eugene T Yanagihara Emi SaegusaBeecroft Gregory K Kobayashi Clifford C M Wong Conway Fung Ernest J Feleppa Kazuhiro Sakamoto

Publish Date: 2011/04/15

Volume: 17, Issue: 4, Pages: 835-841

PDF Link

Abstract

The purpose of this study was to accurately detect lymphnode micrometastases ie metastatic cancer foci that have a size between 20 and 02 mm in nodes excised from colorectal cancer CRC patients and to determine how frequently micrometastases might be missed when standard histological examination procedures are used A total of 311 lymph nodes were removed and examined from 90 patients with Stage I to IV CRC The number of slices of histology sections ranged from 6 to 75 per node average = 255 SD = 111 which provided a total of 7943 slices Lymph nodes were examined in their entire volume at every 50μm and 100μm intervals for nodes smaller and larger than 5 mm respectively The total number of thin sections examined in each node and the number of thin sections where metastatic foci were present were counted The number of thin sections with metastatic foci and the total number of slices was determined for each node In addition the presence or absence of metastatic foci in the “central” slice was determined Micrometastases were found in 12/311 39 of all lymph nodes In the 12 lymph nodes with micrometastases the rate of metastatic slices over all slices was 394 range = 63 to 813 SD = 258 In the central slice of each node micrometastases were present only in 6 of 12 lymph nodes 50 accordingly they were not present in the central slice for half the micrometastatic nodes These 6 nodes represented 19 of the 311 nodes and 111 of the 54 metastatic nodes This study suggests that a significant fraction of micrometastases can be missed by traditional singleslice sectioning half of the micrometastases would have been overlooked in our data set of 311 nodes

Keywords: