Sentinel lymph node investigation in melanoma: detailed analysis of the yield from step sectioning and immunohistochemistry.
OBJECTIVE
To evaluate in detail the extent to which step sectioning and immunohistochemical examination of sentinel lymph nodes (SLNs) in patients with melanoma reveal additional node positive patients, to arrive at a sensitive yet workable protocol for histopathological SLN examination.


METHODS
The study comprised 29 patients with one or more positive SLN after a successful SLN procedure for clinical stage I/II melanoma. SLNs were lamellated into pieces of approximately 0.5 cm in size. One initial haematoxylin and eosin (H&E) stained central cross section was made for each block. When negative, four step ribbons were cut at intervals of 250 microm. One section from each ribbon was stained with H&E, and one was used for immunohistochemistry (IHC).


RESULTS
When taking the cumulative total of detected metastases at level 5 as 100%, the percentage of SLN positive patients increased from 79%, 83%, 83%, 90% to 93% in the H&E sections through levels 1-5, and with IHC these values were 83%, 86%, 90%, 97%, and 100%, respectively. One of six patients in whom metastases were detected at levels 2-5 only had metastases in the subsequent additional lymph node dissection.


CONCLUSIONS
Multiple level sectioning of SLNs (five levels at 250 microm intervals) and the use of IHC detects additional metastases up to the last level in melanoma SLNs. Although more levels of sectioning might increase the yield even further, this protocol ensures a reasonable workload for the pathologist with an acceptable sensitivity when compared with the published literature.
Gietema
H A
HA
Department of Surgical Oncology, VU University Medical Centre, PO Box 7057, 1007 MB Amsterdam, The Netherlands.
Vuylsteke
R J C L M
RJ
de Jonge
I A
IA
van Leeuwen
P A M
PA
Molenkamp
B G
BG
van der Sijp
J R M
JR
Meijer
S
S
van Diest
P J
PJ
D000328:Adult; D000368:Aged; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008545:Melanoma / Q000473:pathology / Q000556:secondary*; D008875:Middle Aged; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D012878:Skin Neoplasms / Q000473:pathology*