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Thyroid Awareness Month – Day 3

Who Is at Risk for Thyroid Nodules?

Thyroid nodules can occur in anyone, but certain factors make them more likely.

👥 Common Risk Factors

Age: Nodules become more common as we get older Female sex: Women develop thyroid nodules 3–4 times more often than men Iodine imbalance: Both deficiency and excess can play a role Family history: Thyroid nodules or thyroid cancer in first-degree relatives Autoimmune thyroid disease: Hashimoto’s thyroiditis increases nodule prevalence

☢️ Higher-Risk Situations

Radiation exposure to the head and neck, especially during childhood Prior radiation therapy for acne, tonsils, or cancer (historical treatments) Certain genetic syndromes (rare, but important)

🧠 Important clarification

Having risk factors does not mean a thyroid nodule is cancer.

➡️ Even in higher-risk individuals, most nodules are benign.

🔍 What matters most?

Risk factors help guide how closely we evaluate, but ultrasound findings ultimately determine:

Cancer risk Need for biopsy Follow-up strategy

📌 Key point for patients:

A thyroid nodule should never be ignored — but it should also never cause unnecessary fear. Proper, evidence-based evaluation is the answer.

👨‍⚕️ Rodrigo Arrangoiz, MD

Surgical Oncologist – Thyroid, Head & Neck, Breast

Mount Sinai Medical Center

📚 References

Haugen BR et al. ATA Guidelines for Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid Guth S et al. Very high prevalence of thyroid nodules. Thyroid Gharib H et al. Evaluation and Management of Thyroid Nodules. Endocrine Practice

Thyroid nodules can occur in anyone, but certain factors make them more likely.

👥 Common Risk Factors

Age: Nodules become more common as we get older Female sex: Women develop thyroid nodules 3–4 times more often than men Iodine imbalance: Both deficiency and excess can play a role Family history: Thyroid nodules or thyroid cancer in first-degree relatives Autoimmune thyroid disease: Hashimoto’s thyroiditis increases nodule prevalence

☢️ Higher-Risk Situations

Radiation exposure to the head and neck, especially during childhood Prior radiation therapy for acne, tonsils, or cancer (historical treatments) Certain genetic syndromes (rare, but important)

🧠 Important clarification

Having risk factors does not mean a thyroid nodule is cancer.

➡️ Even in higher-risk individuals, most nodules are benign.

🔍 What matters most?

Risk factors help guide how closely we evaluate, but ultrasound findings ultimately determine:

Cancer risk Need for biopsy Follow-up strategy

📌 Key point for patients:

A thyroid nodule should never be ignored — but it should also never cause unnecessary fear. Proper, evidence-based evaluation is the answer.

👨‍⚕️ Rodrigo Arrangoiz, MD

Surgical Oncologist – Thyroid, Head & Neck, Breast

Mount Sinai Medical Center

📚 References

Haugen BR et al. ATA Guidelines for Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid Guth S et al. Very high prevalence of thyroid nodules. Thyroid Gharib H et al. Evaluation and Management of Thyroid Nodules. Endocrine Practice

Most thyroid nodules cause no symptoms at all and are found incidentally on imaging or routine exams.

🔹 Common scenario: You feel well — the nodule is discovered on ultrasound

🔹 Important fact: Lack of symptoms does NOT mean the nodule is dangerous (or benign)

👀 When can symptoms occur?

Symptoms are more likely when nodules are large or strategically located:

A visible or palpable lump in the neck Difficulty swallowing or a sensation of food “getting stuck” Hoarseness or voice changes (uncommon, but important) Neck pressure or fullness, especially when lying flat Rarely, shortness of breath

⚠️ Hormone-related symptoms (less common)

A small percentage of nodules produce excess thyroid hormone (“hot” nodules), which may cause:

Palpitations Weight loss Heat intolerance Tremors or anxiety

🚨 When should you seek evaluation?

You should be evaluated if you notice:

✔️ A new or growing neck lump

✔️ Persistent hoarseness

✔️ Difficulty swallowing or breathing

✔️ A personal history of radiation exposure or family history of thyroid cancer

🔍 Bottom line:

Symptoms alone cannot determine whether a nodule is benign or malignant.

➡️ High-resolution ultrasound is essential for proper evaluation.

👨‍⚕️ Rodrigo Arrangoiz, MD

Surgical Oncologist – Thyroid, Head & Neck, Breast

Mount Sinai Medical Center

📌 Take-home message:

Most thyroid nodules are silent.

Don’t rely on symptoms — rely on proper imaging and expert evaluation.

📚 References

Haugen BR et al. ATA Guidelines for Thyroid Nodules. Thyroid Gharib H et al. Evaluation and Management of Thyroid Nodules. Endocrine Practice Durante C et al. JAMA

What Are Thyroid Nodules?

Thyroid nodules are very common in the general population.

🔹 With modern high-resolution ultrasound, thyroid nodules are detected in up to 50–60% of adults

🔹 More than 90% are benign

🔹 Most people have no symptoms and feel completely well

👉 The key is not panic — it’s proper evaluation.

🔍 How should thyroid nodules be evaluated?

The most important first step is a high-resolution thyroid ultrasound, which allows us to:

Accurately measure and characterize nodules Assess features associated with cancer risk Use validated risk-stratification systems (ATA / TI-RADS) Decide whether a biopsy is actually necessary

🧪 A key fact for patients

Only 5–10% of thyroid nodules are cancer.

When thyroid cancer is detected early, cure rates are excellent.

👨‍⚕️ Rodrigo Arrangoiz, MD

Surgical Oncologist – Thyroid, Head & Neck, Breast

Mount Sinai Medical Center

📌 Take-home message:

Having a thyroid nodule is common.

Having it evaluated correctly by an experienced team makes all the difference.

📚 References

Haugen BR et al. ATA Guidelines for Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid Durante C et al. Long-term surveillance of benign thyroid nodules. JAMA Gharib H et al. Fine-needle aspiration biopsy of thyroid nodules. Endocrine Practice

Thyroid Nodules

– Thyroid nodules are very common in the general population. With modern high-resolution ultrasound, nodules can be detected in up to 50% to 60% of adults.

👉 The good news: more than 90% of thyroid nodules are benign.

🔍 What is the best way to evaluate a thyroid nodule?

The first and most important test is a high-resolution thyroid ultrasound. It allows us to:

Accurately characterize the nodule (size, margins, echogenicity, calcifications) Stratify cancer risk using validated systems (such as ATA or TI-RADS) Determine whether a biopsy is necessary

🧪 When is a biopsy needed?

If the ultrasound shows suspicious features, a ultrasound-guided fine-needle aspiration biopsy (FNAB) is recommended.

✔️ This is a safe, minimally invasive, outpatient procedure that provides highly accurate information to determine whether a nodule is benign or malignant, helping avoid unnecessary surgery.

📊 Key facts (evidence-based)

Thyroid nodules are found in up to 60% of adults on ultrasound Only 5% to 10% of nodules are malignant Ultrasound-guided FNAB has high diagnostic accuracy and a very low complication rate

🏥 Experience you can trust

👨‍⚕️ Dr. Rodrigo Arrangoiz

Surgical Oncologist | Thyroid, Head & Neck, and Breast Surgery

Mount Sinai Medical Center

📌 Take-home message: Early detection and proper evaluation of thyroid nodules make a real difference—protecting patients from unnecessary treatments while identifying cancer early when it is most curable.

📚 References

Haugen BR et al. 2015 ATA Guidelines for Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. Russ G et al. European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification (EU-TI-RADS). Eur J Endocrinol. Gharib H et al. Fine-Needle Aspiration Biopsy of Thyroid Nodules. Endocrine Practice. Durante C et al. Long-term Surveillance of Benign Thyroid Nodules. JAMA.

• The Cernea classification:
  • Is used during thyroid surgery to predict the risk of injury to the external branch of the superior laryngeal nerve (EBSLN):
    • Based on its anatomical relation to the superior thyroid artery and the upper pole of the thyroid
  • It includes three types:
    • Type I:
      • The EBSLN crosses more than 1 cm above the upper edge of the thyroid superior pole:
        • The artery-nerve intersection is > 1 cm above the gland
      • Minimal risk during ligation of the superior thyroid vessels
    • Type IIa:
      • The nerve crosses within 1 cm above the superior pole:
        • Distance < 1 cm but above the pole
      • Moderate risk, as it’s close to vascular pedicle
    • Type IIb:
      • The EBSLN crosses below the upper edge of the superior pole:
        • Under the pole
      • Highest risk:
        • Nerve lies within the ligation field
• Clinical Significance:
  • Intraoperative studies show Type IIa + IIb:
    • Account for ~ 65% of cases:
      • Emphasizing the high chance of encountering the nerve near or below the vascular pedicle
  • Type IIb alone:
    • Occurs in up to 48% of cases in some series 
  • Risk of EBSLN injury rises with more inferior nerve trajectories (IIa / IIb):
    • Injuries lead to altered voice quality:
      • Reduced pitch, vocal fatigue, and weakened projection
• Surgical Implications:
  • Routine identification:
    • Especially for Type II subtypes:
      • Is key during superior pole dissection
  • Intraoperative neuromonitoring (IONM) helps detect and preserve the EBSLN:
    • Reducing morbidity
  • Transection of overlying muscles (e.g., sternothyroid):
    • Can improve visualization of the nerve

• The vagus nerve:
  • Also known as the 10th cranial nerve
  • Gives rise to the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) in the neck
  • After descending toward the larynx:
    • The SLN divides into:
      • The internal laryngeal nerve (ILN)
      • External laryngeal nerve (ELN)

• The RLN innervates all of the intrinsic muscles of the larynx:
  • Except the cricothyroid muscle:
    • This muscle, tenses the vocal cords and adducts the vocal cords:
      • Is innervated by the ELN
• The other branch of the SLN, the ILN:
  • Provides sensory innervation to the laryngeal mucosa
• There are many exceptions to the normal innervation of the laryngeal muscles:
  • Which can influence the interpretation of laryngoscopy results or voice changes after thyroid surgery
• A neural anastomosis:
  • That provides additional motor innervation to the muscles of the larynx normally innervated by the injured nerve:
    • Can contribute to an incorrect interpretation of injury during laryngoscopy or stroboscopy
• According to recent clinical studies:
  • Electrical stimulation of the RLN can cause contraction of the cricothyroid muscle:
    • This suggests that extra-laryngeal branches and or other communications of the RLN:
      • Can sometimes contribute to innervation of this muscle
• The laryngeal nerves:
  • Can form a great variety of anastomoses:
    • These various connections among the ILN, ELN, and RLN have been investigated by many anatomists over the centuries
• Claudius Galen:
  • Was the first to describe the communication between the ILN and RLN
  • Currently, Galen’s anastomosis:
    • Is most commonly defined as:
      • The direct communication between the posterior branches of the ILN and the RLN
    • It can occur as:
      • A single trunk
      • A double trunk
      • A plexus

• Besides Galen’s anastomosis, other communications have been observed and described as follows:
  • The arytenoid plexus:
    • Which links the anterior branch of the RLN with the arytenoid branch of the ILN

• The cricoid communication:
  • Which connects branches originating bilaterally from the RLNs with the superior branch from the deep portion of the arytenoid plexus
• The thyroarythenoid communication:
  • Which is formed by the ascending branch of the RLN and the descending branch from the anterior branch of the ILN

• The communication between the ELN and RLN:
  • Human communicating nerve
• The communication between the ILN and ELN
• The communication between the RLN and the sympathetic trunk

• Despite progress in the development of new techniques:
  • Such as intra-operative nerve monitoring:
    • Which help to reduce the risk of iatrogenic injuries during thyroid surgeries and other procedures conducted in close proximity to the laryngeal nerves:
      • The laryngeal muscles are often paralyzed postoperatively due to iatrogenic injury to the laryngeal nerves
• In view of the complexity and variability of the anatomy in this region:
  • Detailed anatomical knowledge is crucial if surgery is to be both successful and safe, and to reduce the risk of nerve injury
• Observing an intra-laryngeal anastomosis during laryngeal surgery or an extra-laryngeal communication between laryngeal nerves during thyroid surgery:
  • Can lead to confusion, misidentification, and an increased risk of iatrogenic injury
• A thorough understanding of the complex anastomoses between the laryngeal nerves is crucial in patients with laryngeal muscle paralysis
  • Paralyzed laryngeal muscles can be spontaneously reinnervated from an anastomosis between laryngeal nerves
  • Additionally, in cases in which surgical reinnervation is required, some of the nerves that form anastomoses can be used as grafts to restore damaged nerve connections
  • On the other hand, variations in the normal anatomy of the laryngeal nerves can disrupt selective surgical laryngeal reinnervation:
    • A procedure based on the assumption that each laryngeal muscle is supplied by only one nerve branch originating from the RLN
  • Anastomoses among laryngeal nerves can result in exceptions to this rule
  • Such anastomoses have been widely described in the literature:
    • However, there is still no consensus about their prevalence and functionality
  • The significant heterogeneity among studies reporting data on anastomoses between the laryngeal nerves is noteworthy:
    • For example, the reported prevalence of the most common communication, Galen’ s anastomosis:
      • Ranges from 25% to 100%
• Prevalence of Galen’s anastomosis:
  • A total of 14 studies (n = 890 hemilarynges) presented data on the prevalence of Galen’s anastomosis
  • The overall pooled prevalence rate:
    • Was 76.7% (95% confidence interval [CI]: 59.0– 90.0)
  • Subgroup analysis revealed no significant difference in the prevalence of Galen’s anastomosis between the right and left sides
  • Subgroup analyses by gender (males vs females) and geographical origin, and the sensitivity analysis, also revealed no significant differences:
    • However, although the difference was not significant:
      • The prevalence of the anastomosis was highest in Europeans (88.2%) and lowest in North Americans (44.8%)
  • Analysis of the different types of Galen’s anastomosis (two studies, n = 261 anastomoses):
    • Showed a significant difference in the prevalence between single versus double trunk and plexus formation
    • But no significant difference between double trunk and plexus formation
    • The most common type of Galen’s anastomosis was a single trunk:
      • With a pooled prevalence rate 92.3% (95% CI: 84.1–97.5)
    • This was followed by the double trunk anastomosis type:
      • With a pooled prevalence of 4.2% (95% CI: 0.5– 10.7)
    • The plexus formation type with a pooled prevalence of 3.5% (95% CI: 0.2–9.5) (I2: 70.4%, 95% CI: 0–93.3; Co- chran’s Q, P value = 0.066
• Prevalence of a communication between the ELN and RLN
  • A total of eight studies (n = 639 hemilarynges) provided data on the prevalence of the communication between the ELN and RLN
  • The overall meta-analysis revealed that this communication was present in:
    • 21.3% of hemilarynges (95% CI: 3.8–46.0)
  • A subgroup analysis showed no significant difference between left and right sides
  • Although the difference was not statistically significant:
    • The pooled prevalence rate calculated for the North American subgroup (32.0%) was twice that for the European subgroup (14.4%)
• Prevalence of the arytenoid plexus:
  • Five studies (n = 478 hemilarynges) included data on the prevalence of the arytenoid plexus:
    • The pooled prevalence rate was 79.7% (95% CI: 41.1–100)
  • In the European subgroup:
    • The arytenoid plexus was observed in 96.9% of hemilarynges (95% CI: 83.6–100)
  • Subgroup analysis revealed no significant difference with respect to side
• Prevalence of the cricoid communication:
  • Two studies (n = 120 hemilarynges) reported prevalence data for the cricoid communication:
    • The pooled prevalence rate was 19.7% (95% CI: 0–100)
  • There was no significant difference in sub- group analysis based on side
• Prevalence of the thyroarytenoid communication:
  • A total of three studies (n = 430 hemilarynges) presented data on the prevalence of the thyroarytenoid communication:
    • The overall pooled prevalence was 6.3% (95% CI: 0.4–16.9)
  • In subgroup analysis, there was no significant difference in pooled prevalence between the right and left sides:
    • The calculated pooled rate for the left side (15.9%) was almost twice that for the right side (8.8%)
• Communication between the ILN and ELN:
  • A total of two studies (n = 280 hemilarynges) reported data on a communication between the ILN and ELN
    • The pooled prevalence estimate of this communication in hemilarynges was 8.8% (95% CI: 0–35.3; I2 97.0%, 95% CI: 92.2–98.8; Cochran’s Q, P value <0.001)
• References:
  • Journal of Voice, Vol. 31, No. 4, 2017

#Arrangoiz #HeadandNeckSurgeon #CancerSurgeon #ThyroidSurgeon #ParathyroidSurgeon #ThyroidExpert #ParthyroidExpert #Teacher #Miami #Mexico

• In 1984 Göran Åkerström, on the basis of 503 necropsies, analysed the location of the parathyroid glands:
  • Together with the work of Gilmour (n=478) and Wang (n=160), they form the foundations of our current knowledge on the subject
• Dr. Juan M. Rangone modified the diagrams from Åkerström’s original publication to come up with the percentages of location of the “normodescended” parathyroid glands:
• A. Percentages of the different locations of the superior parathyroid glands:
  • 80% corresponds to the midglandular variant
  • 12% to the cricopharyngeal variant
  • Usually located 1 cm higher than the crossing of the recurrent laryngeal nerve and the inferior thyroid artery
• B. Percentages of the different locations of the inferior parathyroid glands:
  • Roughly 90% are located at the level, or no more than 1 cm below the inferior pole of the thyroid gland
• Image:
  • 1- External carotid artery.
  • 2- Superior thyroid artery.
  • 3- Inferior thyroid artery.
  • 4- Upper thyroid pole.
  • 5- Lower thyroid pole.
  • 6- Inferior laryngeal nerve (recurrent laryngeal).
  • 7- Pharynx.
  • 8- Cervical trachea.
  • 9- Larynx (thyroid cartilage).
• Recommended Bibliography:
  • Åkerström G, Malmaeus J, Bergström R. (1984) Surgical anatomy of human parathyroid glands. Surgery 95(1):14-21.
  • Wang C (1976) The anatomic basis of parathyroid surgery. Ann Surg. 183(3): 271–275.
  • Gilmour JC (1938) The gross anatomy of the parathyroid glands. J Pathol Bacteriol. 46(1): 133-149.

• Reeve’s Cricothyroid Space:
  • Synonym:
    • Paralaryngingeal space
    • Pemberton space
    • Inter-laryngeal glandular space
• The lower and lateral retraction of the upper thyroid pole:
  • Reveals a diamond-shaped avascular space
• The area is limited:
  • Medially:
    • By the lamina of the thyroid cartilage (superiorly) and cricoid cartilage (inferiorly):
      • Both covered by the cricothyroid muscle
  • Inferolaterally:
    • The space is circumscribed by the medial border of the upper thyroid pole and the upper border of the thyroid isthmus
  • The “roof” of the area:
    • Is covered by 2 or 3 “bridging” blood vessels that must be controlled to access the space
• The “opening” of this virtual space:
  • Prior to the ligature of the upper thyroid pedicle:
    • Is a safety maneuver to protect the external branch of the superior laryngeal nerve
• Landmarks:
  1. Thyroid cartilage
  2. Reeve cricothyroid space
  3. Space with “bridging” blood vessels
  4. Upper thyroid pole
  5. Cricothyroid muscle
  6. External branch of the superior larngeal nerve
  7. Superior thyroid artery
  8. Superior thyroid vein
• Reference:
  • Abdullah H, Bliss R, Reeve T, Delbridge L (2000) Recognition of the avascular space medial to the upper pole of the thyroid and its surgical implications. Asian J. Surg. 23: 86–9.

👉The external branch of the superior laryngeal nerve (EBSLN) has been labelled ‘the neglected nerve’ of thyroid surgery.

👉Most surgeons have simply attempted to avoid this nerve on the assumption that so doing will prevent injury; however, it is now recognized that injury is relatively common and associated with the potential for significant impairment, espe- cially for those who use their voices professionally.

👉I was taught to always attempt to identify the nerve and recommend doing so.

👉Recently Aina and Hisham have shown that the nerve can be routinely identified in over 90% of cases, a level that sets a new benchmark for head and neck surgeons / endocrine surgeons.

👉The key to identifying the nerve is to develop the avascular plane between the cricothyroid muscle and the medial border of the upper pole of the thyroid lobe, a manoeuvre facilitated by lateral retraction of the lobe.

👉Awareness of the various positions of the EBSLN according to the Cernea classification is also essential if the nerve is to be both identified and preserved.

👉Type 1 EBSLN are located well clear of the thyroid, more than 1 cm above the upper pole of the lobe passing directly into the cricothyroid muscle.

👉Type 2a nerves pass in the vicinity of the superior thyroid vessels as they enter the gland substance.

👉Type 2b nerves cross over the anterior surface of the thyroid lobe.

👉Awareness of the anatomic variations, such as the nerve of Galen, a direct communication between the RLN and EBSLN, is important in avoiding injury to the nerve.

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#ParathyroidSurgeon

#CancerSurgeon

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