The status of the cervical lymph nodes is the most important prognostic
factor in squamous cell carcinoma of the upper aerodigestive tract.
The number of positive nodes and the presence of extranodal (or
extracapsular) spread are the two most commonly used prognostic
factors. Other characteristics of prognostic importance are the
size of the node, level of positive nodes, and histologic response
to the tumor in the node. The extent of nodal disease in the neck
has prognostic significance not only for failure in the neck but
also for the development of distant metastases and, possibly,
for recurrence at the primary site [1-3].
Histopathologic examination of neck dissection specimens, therefore,
provides basic information for diagnosis, staging, and prognosis.
Clinicians seldom question the reliability of this examination.
Although extranodal spread of metastatic carcinoma from cervical
nodes is a major prognostic factor [4-6], the clinical implications
of micrometastases remain unclear.
The demonstration of micrometastases in a neck dissection specimen
deemed to be pathologically negative after routine examination,
resulting in upstaging, seems to be more important than the finding
of additional micrometastases in a resection specimen with overt
nodal disease. We conducted a retrospective study to determine
whether serial sectioning and immunohistochemistry using an antibody
against cytokeratin, a marker of epithelial cells, could detect
occult micrometastases in initially pN0 neck dissection specimens
Selected for reassessment of neck dissection specimens were the
paraffin-embedded lymph nodes of 60 previously untreated patients
who presented from June 1986 to December 1990. These patients
had primary squamous cell carcinoma of the oral cavity, oropharynx,
hypopharynx, or larynx; underwent laser microsurgery on the primary
tumor and a unilateral or bilateral neck dissection; and were
classified as pN0 after routine histopathologic examination. Ipsilateral
neck dissection was carried out in 44 patients and bilateral dissection
in 16 patients, so that a total of 76 neck dissection specimens
were evaluated. The primary sites were as follows: oral cavity
(19 patients), oropharynx (6), hypopharynx (9), glottis (13),
and supraglottis (17).
Clinical Staging and Neck Dissection
Preoperative staging of the neck nodes was done by palpation and
ultrasonography. Computed tomography (CT), magnetic resonance
imaging (MRI), and aspiration cytology were not employed routinely.
The neck dissections, either elective (prophylactic) or therapeutic
(when positive nodes were clinically suspected), were selective
; ie, they were confined to the lymph node groups in which
metastases from the specific primary tumor are most likely to
occur [9,10]. In patients with laryngeal and oropharyngeal primaries,
levels II and III were removed, whereas in those with oral carcinoma,
levels I, II, and III were dissected (supraomohyoid neck dissection),
and in those with hypopharyngeal primaries, levels II, III, and
IV were removed (lateral neck dissection) (Figure 1). The nonlymphatic
structures (sternocleidomastoid muscle, internal jugular vein,
and spinal accessory nerve) were preserved.
For routine examination, the neck dissections specimens were fixed
in formalin. All visible or palpable lymph nodes were dissected
free of surrounding fat. All nodes ³ 5 mm were cut in half
and were then embedded in toto for histologic examination. The
"original" surgical pathologic diagnosis was based on
microscopic examination of two to three 1-mm sections from each
node stained with hematoxylin and eosin (H & E).
Subsequent to this "original" examination, the paraffin-embedded
lymph nodes were totally sectioned into 1-mm sections. Every 10th
section was stained with H & E, and every 50th section was
obtained for immunostaining. A mouse monoclonal antibody to pan-cytokeratin
was used for immunostaining. This antibody reacts with human cyto-keratin
of 40, 46, 52, 56, 58, and 65 to 67 kD. To make the antigen (cytokeratin)/antibody
reaction visible, the classic alkaline phosphatase antialkaline
phosphatase (APAAP) technique was used . In this technique,
the APAAP complex is stained with neufuchsin, which causes the
keratin-positive cells to turn red. The remaining tissue is made
visible by counterstaining with hematoxylin.
Since there is no agreed upon definition of micrometastases, the
International Union Against Cancer (UICC) definition for axillary
lymph node micrometastases from breast carcinoma was used. According
to this definition, micrometastases include metastatic deposits
of up to 2 mm in diameter.
Overall, 1,020 lymph nodes from 76 initially pN0 neck dissection
specimens were examined. On average, 13.5 lymph nodes were found
in each of the specimens. The largest axial diameter of each node
was recorded. The nodes were 1 to 22 mm in diameter. A total of
5,999 sections were stained with H & E, and 1,261 sections
Eight lymph nodes (.8%) harbored metastases of a squamous cell
carcinoma, shown in the H & E-stained sections. All metastases
were micrometastases, located in the subcapsular sinus of the
lymph node, and all were found in nodes from level II (upper jugular
group). Six micrometastases were found in lymph nodes < 10
mm in diameter. Two metastases were detected in nodes 20 mm in
diameter. The examination revealed no larger metastases and no
extranodal spread. Im-munostaining found the same eight metastases
but no additional metastases.
Reevaluation of the original slides revealed that three of these
eight metastases had been present but were overlooked. The overlooked
metastases were composed of 200 to 500 tumor cells each; the original
microscopic slides had shown 4 to 6 tumor cells (Figures 2 and
The eight micrometastases were found in six patients (Table 1),
two of whom had two metastases. The primary tumor was located
in the oral cavity in three patients, the oropharynx in two patients,
and the piriform sinus in one patient. Neither serial sectioning
nor immunostaining revealed micrometastases in patients with glottic
or supraglottic primaries.
Two of the six patients with micrometastases had been subjected
to postoperative adjuvant radiotherapy because of positive microscopic
resection margins, despite re-resection of the primary. Another
4 of the total 60 patients had been irradiated for the same reason.
With a median follow-up period of 37 months, none of the 60 patients
developed recurrent metastasis in the neck. Local recurrences
developed in seven patients, and a second primary tumor occurred
in five patients. No distant metastases were observed.
1. Vikram B, Strong EW, Shah JP, et al: Failure at distant sites
following multimodality treatment for advanced head and neck cancer.
Head Neck Surg 6:730-733, 1984.
2. Leemans CR, Tiwari R, Nauta JJP, et al: Regional lymph node
involvement and its significance in the development of distant
metastases in head and neck carcinoma. Cancer 71:452-456, 1993.
3. Leemans CR, Tiwari R, Nauta JJP, et al: Recurrence at the primary
site in head and neck cancer and the significance of neck lymph
node metastases as a prognostic factor. Cancer 72:187-190, 1994.
4. Snyderman NL, Johnson JT, Schramm VL, et al: Extracapsular
spread of carcinoma in cervical lymph nodes: Impact upon survival
in patients with carcinoma of the supraglottic larynx. Cancer
5. Steinhart H, Schroeder HG, Buchta B, et al: Die prognostische
signifikanz von Kapseldurchbrüchen bei Halslymphknotenmetastasen
von Plattenepithelkarzinomen. Laryngo Rhino Otol 73:620-625, 1994.
6. Ambrosch P, Freudenberg L, Kron M, et al: Selective neck dissection
in the management of squamous cell carcinoma of the upper digestive
tract. Eur Arch Otorhinolaryngol vol 253, 1996.
7. Ambrosch P, Kron M, Fischer G, et al: Micrometastases in carcinoma
of the upper aerodigestive tract: Detection, risk of metastasizing,
and prognostic value of depth of invasion. Head Neck 17:473-479,
8. Robbins KT, Medina JE, Wolfe GT, et al: Standardizing neck
dissection terminology. Arch Otolaryngol Head Neck Surg 117:601-605,
9. Candela FC, Shah J, Jaques DP, et al: Patterns of cervical
node metastases from squamous carcinoma of the larynx. Arch Otolaryngol
Head Neck Surg 116:432-435, 1990.
10. Candela FC, Kothari K, Shah JP: Patterns of cervical node
metastases from squamous carcinoma of the oropharynx and hypopharynx.
Head Neck 12:197-203, 1990.
11. Cordell JL, Falini B, Erben WN, et al: Immunoenzymatic labelling
of monoclonal antibodies using immune complexes of alkanine phosphatase
and monoclonal anti-alkaline phosphatase (APAAP complexes). J
Histochem Cytochem 32:219-229, 1984.
12. Carter RL: The pathologist's appraisal of neck dissections.
Eur Arch Otorhinolaryngol 250:429-431, 1993.
13. Glanz H, Eichhorn T: Prognoserelevante pathohistologische
Klassifikation von Halslymphknotenmetastasen (pN) laryngealer
karzinome. HNO 37:481-484, 1989.
14. International (Ludwig) Breast Cancer Study Group: Prognostic
importance of occult axillary lymph node metastases in patients
with invasive breast cancer. Lancet 335:1565-1568, 1990.
15. Schurman SH, Sharon N, Goldschmidt RA, et al: Improved detection
of metastases to lymph nodes and estrogen receptor determination.
Arch Surg 125:179-182, 1990.
16. van den Brekel MWM, Stel HV, van der Valk P, et al: Micrometastases
from squamous cell carcinoma in neck dissection specimens. Eur
Arch Otorhinolaryngol 249:349-353, 1992.
17. Huvos AG, Hutter RVP, Berg JW: Significance of axillary macrometastases
and micrometastases in mammary cancer. Ann Surg 173:44-46, 1971.
18. Fisher ER, Swamidoss S, Lee CH, et al: Detection and significance
of occult axillary node metastases in patients with invasive breast
cancer. Cancer 42:2025-2031, 1978.
19. Trojani M, deMascarel I, Bonichon F, et al: Micrometastases
to axillary lymph nodes from carcinoma of breast: Detection by
immunohistochemistry and prognostic significance. Br J Cancer
20. Sedmak DD, Meineke TA, Knechtges DS, et al: Prognostic significance
of cytokeratin-positive breast cancer metastases. Modern Pathol
21. Chen ZL, Wen DR, Coulson WF, et al: Occult metastases in the
axillary lymph nodes of patients with breast cancer node negative
by clinical and histologic examination and conventional histology.
Dis Markers 9:239-248, 1991.
22. De Mascarel I, Bonichon F, Coindre JM, et al: Prognostic significance
of breast cancer axillary lymph node micrometastases assessed
by two special techniques: Reevaluation with longer follow-up.
Br J Cancer 66:523-527, 1992.
23. Hainsworth PJ, Tjandra JJ, Stillwell RG, et al: Detection
and significance of occult metastases in node-negative breast
cancer. Br J Surg 80:459-463, 1993
24. Clayton F, Hopkins CL: Pathologic correlates of prognosis
in lymph node-positive breast carcinomas. Cancer 71:1780-1790,
25. Jeffers MD, O'Dowd GM, Mulcahy H, et al: The prognostic significance
of immunohistochemically detected lymph node micrometastases in
colorectal carcinoma. J Pathol 172:183-187, 1994.
26. Cutait R, Alves VA, Lopes LC, et al: Restaging of colorectal
cancer based on the identification of lymph node micrometastases
through immunoperoxidase staining of CEA and cytokeratins. Dis
Colon Rectum 34:917-920, 1991.
27. Greenson JK, Isenhart CE, Rice R, et al: Identification of
occult micrometastases in pericolic lymph nodes of Duke's B colorectal
cancer patients using monoclonal antibodies against cytokeratin
and CC49: Correlation with long-term survival. Cancer 73:563-569,
28. Lenz M, Kersting-Sommerhoff B, Gross M: Diagnosis and treatment
of the N0 neck in carcinomas of the upper aerodigestive tract:
Current status of diagnostic procedures. Eur Arch Otorhinolaryngol
29. Steiner W, Hommerich CP: Diagnosis and treatment of the N0
neck of carcinomas of the upper aerodigestive tract. Eur Arch
Otorhinolaryngol 250:450-456, 1993.
30. Crissman JD, Gluckman J, Whiteley J, et al: Squamous cell
carcinoma of the floor of mouth. Head Neck Surg 3:2-7, 1980.
31. Okamoto M, Ozeki S, Watanabe T, et al: Cervical lymph node
metastasis in carcinoma of the tongue: Correlation between clinical
and histopathological findings and metastasis. J Craniomaxillofac
Surg 16:31-34, 1988.
32. Umeda M, Satoshi Y, Yoshiaki T, et al: Lymph node metastasis
in squamous cell carcinoma of the oral cavity: Correlation between
histologic features and the prevalence of metastasis. Head Neck
33. Woolgar JA, Scott J: Prediction of cervical lymph node metastasis
in squamous cell carcinoma of the tongue/floor of mouth. Head
Neck 17:463-472, 1995.
34. Moore C, Kuhns JG, Greenberg RA: Thickness as prognostic aid
in upper aerodigestive tract cancer. Arch Surg 121:1410-1414,
35. Spiro RH, Huvos AG, Wong GY: Predictive value of tumor thickness
in squamous cell carcinoma confined to the tongue and floor of
the mouth. Am J Surg 152:354-360, 1986.
36. Mohit-Tabatabai MA, Sobel HJ, Rush BF: Relation of thickness
of floor of mouth stage I and II cancers to regional metastasis.
Am J Surg 152:351-353, 1986.
37. Steinhart H, Kleinsasser O: Growth and spread of squamous
cell carcinoma of the floor of the mouth. Eur Arch Otorhinolaryngol