Supraomohyoid Neck Dissection Workup

Updated: Mar 07, 2016
  • Author: Antonio Riera March, MD, FACS; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Workup

Laboratory Studies

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  • CBC count and differential

  • Prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (INR) measurements: These studies are especially important in patients with preexisting bleeding diathesis, with hepatitis, or who are taking anticoagulants. Prolonged study results may need to be reversed preoperatively.

  • Platelet count

  • Electrolyte tests

  • Liver enzyme profile

  • Glucose test

  • BUN and creatinine tests

  • Blood type and screen: Because of refinements in the surgical techniques, blood loss has been significantly reduced in these procedures. In situations in which blood loss is expected to be significant, either typing and screening or typing and cross-matching are necessary.

  • Urinalysis

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Imaging Studies

An esophagogram can be helpful in evaluating an occult primary tumor.

Perform CT scan and MRI accordingly if they would help to define node status and treatment planning further.

  • CT scanning with contrast can depict excellent anatomic details.

  • In general, CT scan is the radiologic technique most commonly used to stage the primary lesion; therefore, also include the neck in the examination.

  • Criteria for assessing nodal metastases with CT are (1) increased size (>1.5-cm diameter), (2) poorly defined irregular borders or a rounder shape, (3) presence of central necrosis, (4) nodal grouping, and (5) central hypolucency.

  • The most accurate CT scan criterion for the presence of metastatic adenopathy is central necrosis. The node periphery is usually thick and enhances with contrast. CT scanning also reveals extracapsular spread by enhancement of the nodal capsule.

  • Some radiologists feel that CT scanning demonstrates paratracheal node involvement better than MRI.

  • MRI reveals tumor necrosis and extracapsular spread with less precision than CT scan, but MRI is better for assessing enlarged LNs that are not necessarily metastatic.

  • MRI may also be used in patients who are allergic to iodinated contrast.

  • According to some radiologists, MRI also appears to reveal retropharyngeal node involvement better than CT scan.

Some institutions use ultrasonography and ultrasound-guided aspiration cytology to determine cervical neck metastasis. Ultrasound-guided aspiration cytology has a specificity of nearly 100%.

Positron emission tomography (PET) has recently emerged as an adjunct in the diagnosis of LN metastasis.

  • In recent studies, PET has shown positive findings for lymph node metastasis when CT scan and MRI findings were negative. An FDG-PET scan provides physiologic and biochemical data. Glucose metabolism in neoplastic cells produces increased uptake on FDG-PET scanning, which correlates strongly with viable tumor cells. Therefore, FDG-PET may be helpful in the assessment of neck metastasis and even distant metastasis.

  • Additionally, PET scanning has shown the ability to differentiate active tumors from chronic fibrotic changes. Therefore, PET may become more useful than CT scan and MRI in the detection of recurrent head and neck cancer. Furthermore, the dual use of the PET and CT scanners produces fused PET and CT scan images, which can further enhance the results of the PET scan. The definitive role of PET and PET/CT scans is evolving and showing great potential in the assessment of metastatic neck disease, the early diagnosis of recurrent head and neck cancer, and the status of the neck after chemoradiotherapy.

  • The most recent diagnostic guidelines for the use of PET/CT in head and neck oncology are (1) detection of occult primary tumors, particularly in patients in which the conventional imaging tests are negative; (2) detection and staging of neck metastasis in the negative neck after evaluation with CT or MRI; (3) detection of distant metastasis in patients with advanced metastatic neck disease; and (4) detection of residual or recurrent disease.

Sentinel lymph node biopsy: [13, 14, 15, 16] A sentinel node is the first node of a particular group of nodes to receive the regional lymphatic flow from the primary site. The concept and the procedure for the sentinel lymph node biopsy used in the evaluation of metastatic neck nodes in patients with head and neck squamous cell carcinoma is similar to the one used in the evaluation of nodal disease in skin melanoma. If the sentinel lymph node biopsy is negative, no further lymphadenectomy surgery is necessary. However, the sentinel lymph node biopsy applied to the mucosal cancer of the upper aerodigestive tract is still in the process of evaluation in research trials. Results in this regard are encouraging. Nevertheless, its application in the assessment of neck metastasis is still not established and standardized in the clinical setting.

Biotumor markers and molecular methods: [17, 18] New research techniques have been developed to detect micrometastasis of squamous cell carcinoma by using highly specific biotumor markers and molecular methods. The research is this regard is very active, with goals to impact diagnosis, prognosis, and therapy. However, the practical application, prognosis, and management significance is unknown until further studies are completed in prospective clinical trials.

Perform chest radiography to exclude metastatic disease.

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Other Tests

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  • A complete physical examination is mandatory and includes evaluation of neurologic, cardiovascular, and respiratory status.

    • Palpate the patient's neck to define size, location, mobility, and degree of softness or hardness of any mass.

    • Evaluate the patient's weight and nutritional status.

  • Perform ECG as indicated.

  • Perform other evaluations, with further medical consultations and recommendations, as indicated.

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Diagnostic Procedures

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  • Supplement the examination with mirror laryngoscopy, flexible nasopharyngolaryngoscopy, or both.

  • When the primary tumor is known, perform a panendoscopy to exclude a second primary tumor. Performing biopsy of the primary lesion is necessary. When the primary tumor is not known, perform panendoscopy to look for the primary tumor. Obtain random biopsy samples of the pyriform sinus, base of tongue, tonsillar area, and nasopharynx to exclude occult malignancies.

  • Transnasal esophagoscopy (TNE) can be used in the office to look for primary tumor or tumors and, if found, to take the necessary biopsy or biopsies. TNE can be used to biopsy suspicious lesions in the nasopharynx, glottis, supraglottis, and the esophagus. TNE is done with topical anesthesia in the same fashion as with flexible laryngoscopy. The endoscope used in TNE is fitted with suction and biopsy port to accomplish the same goals as the classic panendoscopy.

  • When the patient has a neck mass, a fine-needle aspiration biopsy (FNAB) for pathology evaluation is indicated.

  • Open biopsy of the neck is indicated only when results of previous physical examination measures (eg, FNAB, random biopsies, endoscopy) are inconclusive.

  • Frozen section can be used intraoperatively to assess neck metastasis of suggestive nodes.

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Histologic Findings

Biopsies of the primary site reveal the etiology of the initial mass and the characteristics of the tumor involved (eg, SCC of the upper aerodigestive tract, nasopharyngeal carcinoma, thyroid carcinomas, head and neck skin cancer). FNAB findings of the neck metastasis confirms the pathology findings of the primary tumor. FNAB findings also help determine the etiology of the cervical adenopathy when the patient has a neck metastasis from an occult primary tumor. Frozen section can be used intraoperatively for suggestive nodes to confirm cervical metastasis.

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