Micrometastases in carcinoma of the upper aerodigestive tract: detection, risk of metastasizing, and prognostic value of depth of invasion.
BACKGROUND
The purpose of this study was to investigate the incidence of micrometastases from squamous cell carcinomas of the upper aerodigestive tract in neck dissection specimens, and to determine whether features of the primary tumor might be of prognostic value for metastasizing.


METHODS
Seventy-six originally pNO staged neck dissection specimens from 60 patients were evaluated using serial sectioning in 10-micrometer intervals, H&E staining and immunostaining with an antibody to pan-cytokeratin. The influence of the variables pT-category, cytologic grade, and maximum depth of invasion of the primary tumor on the nodal status was analyzed in 128 patients.


RESULTS
The examination of 1020 lymph nodes from 76 neck dissection specimens revealed 8 micrometastases in 6 specimens (7.9%) from 6 patients with oral and pharyngeal primaries, resulting in upstaging. Six micrometastases were located in lymph nodes of 3-6 mm in diameter. Depth of invasion was the only significant risk factor for metastasizing selected in logistic regression.


CONCLUSIONS
The surgeon should be aware of a relatively high incidence of micrometastases from oral and pharyngeal carcinomas, which are neither detectable preoperatively nor histopathologically by a reasonable effort. The measurement of the maximum depth of invasion of the primary can delineate a group of patients who should be treated by elective neck dissection.
Ambrosch
P
P
ENT Department, University of Göttingen, Germany.
Kron
M
M
Fischer
G
G
Brinck
U
U
D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D004396:Coloring Agents; D005544:Forecasting; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D007633:Keratins / Q000032:analysis; D007822:Laryngeal Neoplasms / Q000473:pathology* / Q000601:surgery; D053685:Laser Therapy; D016015:Logistic Models; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology*; D008866:Microsurgery; D009062:Mouth Neoplasms / Q000473:pathology* / Q000601:surgery; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010610:Pharyngeal Neoplasms / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors
D004396:Coloring Agents; D007633:Keratins