Pathologic evaluation of sentinel lymph nodes in oral squamous cell carcinoma.
BACKGROUND
The objective of this study was to determine the relative efficacy of different methods of pathologic evaluation of sentinel lymph nodes.


METHODS
In this prospective study, sentinel nodes were evaluated for occult metastasis using frozen section, imprint-cytology, hematoxylin-eosin staining, serial step sectioning (SSS) with hematoxylin-eosin, and immunohistochemistry (IHC). Metastases were classified into macrometastasis (>2.0 mm), micrometastasis (0.2 mm-2.0 mm), isolated tumor cells (<0.2 mm).


RESULTS
Occult metastasis was detected in 20 of 80 patients. Frozen section and imprint cytology identified metastasis in 10 of 20 patients, hematoxylin-eosin stain in 13 patients; SSS upstaged the disease in a further 7 patients (9%). Frozen section detected macrometastasis in 7 of 8 cases but failed to detect smaller metastases (missed micrometastasis in 4 of 7 and isolated tumor cells in 5 of 5). SSS upstaged the disease by 10%, and sensitivity and negative predictive value of SSS with hematoxylin-eosin stain were 90% and 97%, respectively.


CONCLUSIONS
Frozen section and imprint cytology are not effective in identifying occult metastasis. IHC and SSS are required to identify micrometastasis and isolated tumor cells.
Head and Neck Oncology Service, Mazumdar Shaw Cancer Center, Bangalore, India.
Nirav P
NP
Trivedi
Hiran Kattilaparambil
HK
Ravindran
Shanmugham
S
Sundram
Subramania
S
Iyer
Vikram
V
Kekatpure
Sundeep
S
Durah
Moni Abraham
MA
Kuriakose
D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D003584:Cytological Techniques; D005629:Frozen Sections; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D013194:Staining and Labeling; D014062:Tongue Neoplasms / Q000473:pathology*