Endocrine—Neck Mass
Concept
Usually benign in practice, but a neck mass won’t be benign during the exam. Differential diagnosis should be complete and your H+P should guide you towards the underlying process. “Rule of 80s” after age 40:
80% non-thyroid neck masses in adults are neoplastic 80% of neoplastic masses are malignant
80% of malignant masses are metastatic
80% malignancies in adults are squamous cell carcino- mas
80% of metastatic are from primaries above level of clavicle
Be wary of a neck mass in an infant, in the midline, or in an HIV+ patient (lymphoma).
Way Question May be Asked?
“43 y/o male presents to the office with a mass in his left neck. It is non-tender and has been there for about 3 months. He has a significant smoking history. What do you want to do?” You will likely have to ask some more ques- tions on your H+P regardless of the way the scenario is given to you. Look for clues as to where the mass is (may be given “left anterior neck”) and the age/sex of the patient to help guide you.
How to Answer?
History
Age (very important here) Location (again, very important) Duration
Drainage (brachial cyst?) Pain
Tobacco/Alcohol use
Hoarseness Dysphagia
History (HIV+, prior malignancy)
Systemic symptoms (“B symptoms” with lymphoma?) Previous head/neck surgery (suspicious mole/melanoma
removed? Was it overlying parotid gland?)
Physical Exam
Location Tenderness Fixed/Mobile
Movement with swallowing Pulsatile (caratoid body tumor) Sinus (cyst)
Nasopharynx Oral Cavity Larynx Neck (thyroid)
Other lymph node basins (axillae, groin) Skin
Breast
Abdomen (palpable liver/spleen) Stool guiac (maybe metastatic)
Diagnostic Tests
FNA (critical here and helpful in neck masses) CXR (lung or mediastinal pathology)
CT Scan of the face/neck (sinuses/oral cavity/nasophar- ynx/larynx)
+/− MRI
+/− U/S of neck (useful to evaluate thyroid/parathyroid) +/− Thyroid scan (again, useful to evaluate
thyroid/parathyroid)
Blood tests (as always, complete labs, CBC with dif- ferential, in select cases, calcitonin/calcium levels, thyroid hormones, and examination of blood smear)
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Differential Diagnosis
Midline
Thyroglossal duct cyst Dermoid cysts
Pyramidal lobe of thyroid Lateral
Lymph node—infected vs. metastatic Brachial cleft cyst
Supraclavicular
Lymph node—infected vs. metastatic Submandibular/Preauricular mass
Lymph node Parotid gland Salivary gland
Don’t forget inflammatory etiologies:
Lymphadenitis Tuberculosis Tularemia Cat scratch Toxoplasmosis Sarcoidosis Viral
Treatment
Thyroglossal duct cyst
U/S neck to confirm presence of normal thyroid Excision with middle portion of hyoid bone and
follow any tissue to base of tongue (Sistrunk procedure)
Brachial cleft cyst—always surgical excision, be careful of anatomic pathway!
First Brachial Cleft
Opening at angle of mandible, passes through facial nerve
Second (most common)
Opening anterior border of SCM, passes between carotid bifurcation
Third
Opening at lower border of SCM, passes behind carotid
Lymph node = squamous cell carcinoma NPL in your office
Excisional biopsy under anesthesia + exam under anesthesia with:
Panendoscopy of upper aerodigestive tract:
Direct laryngoscopy Rigid esophagoscopy Rigid bronchoscopy
Biopsies of nasopharynx, base of tongue, pyriform sinus
Excision of primary site (if found) and modified radical neck dissection
Lymph node = adenocarcinoma
CT scan of neck/chest/abdomen/pelvis Bilateral mammograms
EGD
BE/Colonoscopy
If primary found, this represents Stage 4 disease and chemotherapy may be offered
If no primary found, excisional biopsy + modified radical neck dissection on that side
Send for ER/PR receptors and mucin stain (r/o breast melanoma/lymphoma)
Lymph node = thyroid Thyroid U/S Thyroid Scan
Total thyroidectomy +
Enlarged nodes for papillary CA
Central lymph node dissection and Modified radical for medullary
Lymph node = lymphoma Excisional biopsy of node
CT scan neck/chest/abdomen/pelvis Bone marrow biopsy (Stage IV disease)
Stage disease (number of nodal groups/which side of diaphragm)
Staging laparotomy?
Chemotherapy (CHOP)
Post-op XRT should be considered to neck after radical neck dissection
Important anatomy to remember Anterior triangle boundaries
Lateral = SCM
Medial = midline of neck
Superior = inferior edge of mandible Posterior triangle boundaries
Inferior = clavicle Anterior = SCM Posterior = trapezius Steps in radical neck dissection:
T-incision
Locate and protect mandibular and cervical branches of facial nerves
Divide anterior facial vessels
Remove contents of submental and submandibu- lar triangles
Ligate external jugular vein close to subclavian Protect spinal accessory, phrenic, brachial
plexus while removing fat/lymphatic tissue in posterior triangle
Low division of omohyoid behind SCM Division of SCM
Open carotid sheath and ligate IJ close to clavicle Ligate submaxillary duct
In modified radical neck dissection, the following are preserved:
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Strikeouts 51
Spinal accessory nerve Internal jugular vein SCM
Common Curveballs
Metastatic thyroid cancer FNA will be indeterminate
Scenario will switch several times from squamous cell carcinoma to adenocarcinoma to lymphoma Melanoma overlying parotid gland (modified radical
neck+ superficial parotidectomy) Won’t be able to identify primary site
Will find primary site and be asked how to perform resection
Seroma under skin flap
Chylous fistula post-op in left neck dissection Carotid artery blowout post-op
Damage to any nerve (phrenic, spinal accessory, vagus, hypoglossal)
Strikeouts
Not knowing the different algorithms between FNA yielding squamous cell carcinoma vs. lymphoma vs.
adenocarcinoma Not having a broad DDx Not performing FNA Not knowing surgery for:
Thyroglossal duct cyst
Most common branchial cleft cyst
Not being able to describe modified neck dissection or difference from complete radical
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