Cervical Lymphadenectomy:
General Considerations

I. INDICATIONS FOR NECK DISSECTION: SQUAMOUS CELL CARCINOMA

A. N0 Neck Disease
1. When the risk of occult (undetectable) neck metastases is substantial and irradiation is not to be used

2. When the neck needs to be entered for

a. Access to tumor for removal

b. Access to donor vessels for free tissue transfer

B. N1 or Greater Neck Disease

II. INDICATIONS FOR NECK DISSECTION: NONSQUAMOUS CELL CARCINOMA

A. Thyroid Cancer
1. Nodal metastases present (well-differentiated thyroid carcinoma)

2. All cases of medullary thyroid cancer other than subclinical disease identified through screening

B. Selected Cutaneous Malignancies With Potential for Cervical Metastases (such as melanoma, Merkel cell carcinoma, and squamous cell carcinoma)

1. Merkel cell carcinoma
a. The N0 neck usually treated with irradiation only

b. N+’ve disease treated with lymphadenectomy and irradiation

2. Squamous cell carcinoma of the skin

a. In general, elective lymphadenectomy not performed

b. Indicated for N+’ve disease, usually with postoperative irradiation

C. High-Grade Salivary Gland Malignancies

1. In general, there is no need for elective lymphadenectomy (N0 disease) because potential occult metastases will be addressed by cervical extension of the irradiation used as adjuvant therapy for all high-grade salivary gland malignancies.

2. Controversy persists with some supporting elective neck dissection for high-grade mucoepidermoid carcinoma and squamous cell carcinoma of salivary gland origin.

III. CONTRAINDICATIONS TO NECK DISSECTION

These guidelines must be considered “relative contraindications” in that every patient is evaluated and treated as a unique individual employing general concepts for direction.

A. Rigidly fixed disease

B. Vertebral involvement

C. Involvement of the base of skull with or without intracranial disease

D. Distant metastatic disease

IV. CONTROVERSIES: SQUAMOUS CELL CARCINOMA

A. Elective Treatment of the Neck for Squamous Cell Carcinoma
1. Despite advances in imaging (CT, MRI, PET) and pathologic assessment (ultrasound-guided FNA), the assessment of metastases to the neck remains inaccurate. As a result, management decisions for individual patients without clinically identifiable metastases (N0 status) are not based on certainty, but rather a probability that occult spread to nodes has occurred. Investigators have variably supported elective neck treatment when the estimated rate of occult nodal metastases is 10%, 15%, 20%, or even 30%. These percentages vary widely because they derive from a subjective assessment balancing an uncertain gain with a poorly defined morbidity. The uncertain gain is an increase in survival from treating occult disease before it becomes clinically apparent. The poorly defined morbidity is the impact of extending treatment to include a body part that has a high likelihood of being normal (uninvolved with cancer). If the 20% occult metastatic rate is used to select cases for elective treatment, then 80% of patients will receive additional treatment needlessly. If the morbidity from treatment is minor, then this “over-treatment” may be acceptable.

2. We employ elective neck dissection liberally in the management of squamous cell carcinoma of the head and neck primarily as a diagnostic tool to determine the need for postoperative irradiation. When considered in this context, elective neck dissection is more morbid but also more accurate than CT, MRI, PET, or ultrasound with FNA. Elective neck dissection, which is done selectively to minimize the greater morbidity of a comprehensive (Levels I through V) neck dissection, may occasionally also be therapeutic when a single small nodal metastasis (N1) is identified within the first echelon nodal drainage.

3. Elective neck irradiation rather than neck dissection is employed when the tumor at the primary site is treated with irradiation and the risk of occult nodal metastases is substantial. It is an accepted principle to limit treatment to a single modality where possible. Single modality therapy is most commonly employed for stage I, stage II, and selected stage III cancers. Most stage III and stage IV cancers are treated with combined modality therapy.

4. Data is emerging that treatment of a neck that is clinically N0 may be more effective than observation in managing cases at high risk for developing nodal metastases. It is this group of patients that are currently targeted for either elective neck dissection or elective neck irradiation. It should be noted, however, that evidence is still lacking to definitively support elective treatment of a neck over observation with treatment reserved for cases developing clinically apparent disease.

B. Indications for Elective Treatment (Lymphadenectomy or Irradiation) of the Neck for SCC

1. Indications at any site
a. Capillary-lymphatic space permeation: all cases

b. Perineural spread: most cases

These histologic findings identified following resection at the primary site generally warrant combined modality therapy (postoperative irradiation). If these findings are at the site identified before an elective neck is performed, elective irradiation will supplant the need for elective neck dissection. Extension of the radiation fields to include the neck will occur in the course of treating the primary site.

2. Lip
a. Consider for T3, T4 tumors

b. Consider for tumors of any T classification involving the oral commissure

c. Consider for any recurrent lip cancer

3. Oral cavity

a. Most T3, T4 tumors

b. Any T classification with depth of invasion >4 mm

c. Consider irradiation for all but the most superficial buccal squamous cell carcinoma

d. Consider bilateral neck treatment for any tumor of the floor of mouth, as well as those at other sites in the oral cavity encroaching on the midline

4. Oropharynx

Only the most superficial T1 tumors are treated without addressing occult neck metastases. The high risk of involvement of the retropharyngeal nodes (not commonly addressed by neck dissection) generally warrants elective management of the neck with irradiation rather than surgery.

5. Nasopharynx

a. Irradiation, supplemented by chemotherapy, is the primary treatment modality for the primary site and regional metastases.

b. Persistent neck disease after irradiation may be addressed surgically.

6. Larynx

a. Supraglottic cancers: Elective treatment of the neck is suggested for all but the most superficial T1 suprahyoid epiglottic cancers.

b. Glottic cancers: Elective treatment of the neck is suggested for all but T1 and T2 glottic cancers.

c. Subglottic cancers: Elective treatment of the neck is suggested for all cases.

7. Hypopharynx

Elective treatment of the neck is suggested for all cases

C. Role for Irradiation of Node Positive Disease

1. General rule: Metastases to neck nodes greater than 2 cm in size are not readily cured with irradiation alone.

2. Exceptions

a. Metastases from nasopharyngeal carcinomas

b. Lymphoepitheliomas

3. Controversy

a. If the primary site and neck with positive nodes is treated with irradiation, is a subsequent neck dissection necessary when there is a complete clinical response at the primary site and in the neck based on CT imaging and clinical exam?
(1) Generally accepted for cN1 disease: no neck dissection is needed.

(2) Controversial for cN2 or cN3 disease (as assessed prior to irradiation). An “elective” neck dissection is needed after irradiation despite a complete clinical response.

D. In-Continuity Versus Discontinuous Neck Dissection

1. Separate resection of the primary site tumor from the neck dissecti iminishes the morbidity incurred by removing normal intervening structures. Discontinuous neck dissection has been supported by some in the treatment of oral cavity cancers. Additional support for this practice has developed with expanded use of laser resection through a transoral approach in the oral cavity and endoscopic resection at other sites. In contrast, others have identified a lower recurrence rate and higher survival when the neck dissection is done in-continuity with the primary tumor.

2. We advocate an intermediate position wherein the intervening lymphatics are removed between the primary site and the neck dissection contents with preservation of uninvolved structures.

a. Standard continuous resection of tongue cancer: the primary site and floor of mouth contents including mucosa, sublingual glands, distal Wharton’s duct, lingual nerve, mylohyoid, and genioglossus are removed along with the contents of the neck dissection.

b. Standard discontinuous neck dissection for tongue cancer: the primary tumor is removed transorally, leaving the floor of mouth contents in place. A neck dissection is done with the upper border defined anatomically by the lower border of the mandible and more practically by the submandibular ganglion of the lingual nerve.

c. Intermediate approach

(1) The primary tumor is removed along with the floor of mouth contents. In a fashion similar to a Selective neck dissection sparing the sternocleidomastoid muscle and spinal accessory nerve, the mylohyoid, genioglossus, and lingual nerve are preserved. All other tissue intervening between the primary site and the neck dissection contents is removed.

(2) This modified approach is appropriate in the absence of a deeply infiltrating tumor with capillary lymphatic space permeation. These more aggressive tumors are resected en bloc through an incontinuity approach.

E. Extent of Neck Dissection

1. Clinically N+’ve (N1, N2, N3)
a. Radical neck dissection is the standard

b. Exceptions:

(1) Preserve spinal accessory nerve when adequate tumor removal is not compromised.

(2) May consider selective Levels I, II, III, IV neck dissection if a solitary small Level I lymph node is involved (N1).

(3) When a radical neck dissection is done on the contralateral side, the ipsilateral side may be modified to limit the extent of dissection despite clinically apparent disease in 1 of the anterior levels.

2. Clinically N0

a. Lip: Levels I, II, III, IV (identify, dissect, and elevate marginal mandibular nerve to permit full removal of the perifacial artery lymph nodes (prevascular and postvascular nodes).

b. Oral cavity: Levels I, II, III, IV

(1) Anterior oral cavity: Dissection of marginal mandibular nerve is the same as for lip.

(2) Posterior oral cavity: The peri-facial nodes are not at the same risk for metastases. The marginal mandibular nerve may be protected without full dissection through its superior displacement with elevation of the posterior facial vein and submandibular gland fascia.

c. Oropharynx: Levels I, II, III, IV

d. Larynx: Levels II, III, IV

e. Hypopharynx: Levels II, III, IV

3. Special considerations

a. Supra-omohyoid dissection leaves Level IV behind. “Skip metastases” to Level IV occur without identifiable intervening metastases. The morbidity incurred from elevation of the omohyoid to remove Level IV is limited to
(1) Increased risk of chylous fistula

(2) Increased risk of phrenic nerve injury

(3) These risks are small; the additional 10 minutes operating time to remove Level IV appears justified.

b. The supra-spinal accessory segment of Level II that has been labeled IIB by the Sloan Kettering group and IIA by the Iowa group is rarely involved with metastatic disease from squamous cell carcinoma of the upper aerodigestive tract when the neck is clinically staged N0. There were no cases among the 44 studied at Sloan-Kettering and the 71 at University of Iowa in which metastatic disease was confined the supraspinal region of Level II without metastatic disease elsewhere. When the neck dissection is done as a “biopsy” to determine the need for subsequent irradiation, dissection of this region may not be necessary. If neck metastases are identified at other levels, then the postoperative irradiation will be administered and adequately address microscopic disease in this region. Less shoulder dysfunction is expected from limiting dissection of Level II to clearing the spinal accessory nerve and removing the adipo-lymphatic compartment below it.

V. PREOPERATIVE CONSIDERATIONS

A. Tumor Board Discussion (see Tumor board protocol)
1. To assess alternatives to neck dissection

2. To determine the extent of neck dissection likely to be necessary

B. CT/MRI

1. To identify subclinical (nonpalpable) neck disease; especially useful in the obese or muscular neck

2. To identify extent of gross disease:

a. Extracapsular spread of disease may be identifiable

b. Involvement of the carotid, internal jugular, neck musculature, cranial nerves, base of skull, or mandible

C. Consultation

1. Radiation oncology
a. For all cases: to assist with disposition determined at tumor board

b. For selected cases: to place afterload catheters intraoperatively for brachytherapy

2. Other services as dictated by comorbidity and extent of disease

a. Cardiothoracic surgery if extension of dissection inferior to the clavicle is possible

b. Vascular surgery if carotid resection possible

D. Consent

1. Describe procedure including the benefits.

2. Explain risks and potential complications:

a. Bleeding, transfusion, hematoma

b. Wound infection

c. Shoulder weakness, adhesive capsulitis, pain

d. Prolonged facial or neck edema especially with irradiation

e. Chylous fistula (at risk of Level IV dissection)

f. Deformity from neck scar, loss of fat, and possibly the SCM

g. Cranial nerve deficits (emphasize if disease is near a particular nerve)

(1) XI

(2) X hoarseness, dysphagia, aspiration

(3) IX dysphagia

(4) XII dysarthria, dysphagia

(5) VII marginal mandibular branch weakness and rare total facial paralysis unless the neck disease is high in zone II.

h. Anesthesia (numbness) of the neck skin, earlobe, and possibly the tongue

i. Anesthetic risks (stroke, death, MI)

j. Possibility of need for further surgery or other treatment (XRT/chemotherapy)

E. Type and screen for transfusion if the neck dissection is done concurrently with another procedure with expected blood loss. The uncomplicated neck dissection in isolation should not require transfusion.

VI. CPT CODING

A. See Neck dissection protocols

VII. SUGGESTED READING

A. Baker SR, Krause CJ. Carcinoma of the lip. Laryngoscope. 1980;90:19-27.

B. Byers RM, Weber RS, Andrews T, McGill D, Kane R, Wolf P. Frequency and therapeutic implications of “skip metastases” in the neck from squamous cell carcinoma of the oral to ad Neck J. 1997;19:14-19.

C. Eisele DW, Clifford AR, Johns ME. Carcinoma of the oral cavity and pharynx. In: Lee KJ, ed. Essential Otolaryngology. 6th ed. Norwalk, CT: Appleton & Lange: 1995:535-554.

D. Fakih AR, Rao RS, Borges AM, Patel AR. Elective versus therapeutic neck dissection in early carcinoma of the oral tongue. Am J Surg. 1989;158:309-313.

E. Fletcher GH. Elective irradiation of subclinical disease in cancers of the head and neck. Cancer. 1972;29:1454.

F. Hoffman H, Eschwege F, Krause C. Combined surgery and radiotherapy. In:, Clark JR, Snow GB, eds. Multimodality Therapy for Head and Neck Cancer, Stuttgart, New York: Georg Thieme Verlag. 1992:76-94.

G. Hoffman H, Funk G, Endres D. Evaluation and surgical treatment of tumors of the salivary glands.) In: Stanley E. Thawley, et al, eds. Comprehensive Management of Head and Neck Tumors. 2nd ed. 1999:1147-1182.

H. Hoffman HT, Karnell LH, Shah JP, Ariyan S, Brown GS, Fee WE, Glass AG, Goepfert H, Ossoff RH, Fremgen AM. Hypopharyngeal cancer patient care evaluation. Laryngoscope. 1997;107:1005-1017.

I. Jones KR, Lodge-Rigal D, Reddick RL, Tudo GE, Shockley WW. Prognostic factors in the recurrence of stage I and II squamous cell cancer of the oral cavity. Arch Otolaryngol Head Neck Surg. 1992;118:483-485.

J. Kraus DH, Rosenberg DB, Davidson BJ, Shaha AR, Spiro RH, Strong EW, Schantz SP, Shah JP. Suprasternal accessory lymph node metastases in supra-omohyoid neck dissection. Am J Surg. 1996;172:646-649.

K. Leemans CR, Tiwari R, Nauta JJ, et al. Discontinuous versus incontinuity neck dissection in carcinoma of the oral cavity. Arch Otolaryngol Head Neck Surg. 1991;117:1003-1006.

L. Lindberg R. Distribution of cervical lymph node metastases from squamous cell carcinoma of the upper respiratory and digestive tracts. Cancer. 1972;29:1446-1449.

M. Medina JE, l. Neck. In: Gluckman JL, ed. Renewal of Certification Study Guide in Otolaryngology Head and Neck Surgery. Dubuque, Iowa: Kendall/Hunt Publishing Co. 1998:433-490.

N. Spiro RG, Strong EW. Discontinuous partial glossectomy and radical neck dissection in selected patients with epidermoid carcinoma of the mobile tongue. Am J Surg. 126:544-546

O. Spiro RH, Huvos AG, Wong Gy, Spiro JD, Gnecco CA, Strong EW. Predictive value of tumor thickness in squamous carcinoma confined to the tongue and floor of the mouth. Am J Surg. 1986;152:345-350.

P. Talmi YP, Hoffman HT, Horowitz Z, McCulloch TM, Funk GF, Graham SM, Peleg M, Yahalom R, Teicher S, Kronenberg J. Patterns of metastases to the upper jugular lymph nodes (the “submuscular recess”). Head Neck. 1998;20:682-686.

Q. Van den Brekel MWM, Casteligns JA, Reitsma LC, Leemans CR, van der Waal I, Snow GB. Outcome of observing the N0 neck using ultrasounographic-guided cytology for follow-up. Arch Otolaryngol Head Neck Surg. 1999;125:153-156.

R. Vandenbrouck C, Sancho-Garnier H, Chassagne D, Saravane D, Cachin Y, Micheau C. Elective versus therapeutic radical neck dissection in epidermoid carcinoma of the oral cavity: results of a randomized clinical trial. Cancer. 1980;46:386-390.

S. Zitsch RP, Park CS, Renner GJ, Rea JL. Outcome analysis for lip carcinoma. otolaryngology. Head Neck Surg. 1995;113:589-596.