ENP101: Papillary Thyroid Cancer

Summary

---

Podcast Summary: ENP101 – Papillary Thyroid Cancer

Podcast: Endocrine News Podcast
Host: Aaron Lohr, Endocrine Society
Guest: Dr. Nikita Dear, Chief Endocrinology Fellow, UT Health Science Center Houston
Date: September 3, 2025
Episode Theme: In-depth discussion on papillary thyroid cancer (PTC), including risk factors, presentations, diagnostics, treatment, and a rare case of ectopic papillary thyroid cancer.

---

Episode Overview

In this episode, host Aaron Lohr and Dr. Nikita Dear explore the fundamentals of papillary thyroid cancer—the most common form of thyroid cancer—and delve into the rare phenomenon of ectopic papillary thyroid cancer. Dr. Dear shares insights from her recent case study presented at the Endo2025 meeting, highlighting diagnostic challenges, clinical approaches, and implications for both patients and practitioners when papillary thyroid cancer presents in unusual locations.

---

Key Discussion Points & Insights

1. Papillary Thyroid Cancer: Causes and Prevalence

• Definition & Classification:
  • Papillary thyroid cancer (PTC) is the most common thyroid malignancy, accounting for 80-85% of cases.
  • Arises from follicular epithelial cells and is classified as a well-differentiated thyroid cancer. (01:06)
• Risk Factors:
  • Primary risk: Exposure to ionizing radiation.
  • Other risks: Age, female sex (3x risk vs. males), family history.
  • "Being female is actually three times higher incidence than being a male." – Dr. Dear (01:26)
• Epidemiology:
  • Increased prevalence in the last 50 years, mostly due to improved detection (widespread imaging, fine needle aspiration).
  • Despite rising incidence, mortality remains low. (01:35)

2. Presentation of Papillary Thyroid Cancer

• Typical Presentation:
  • Most often found as an incidental, asymptomatic thyroid nodule.
  • Symptomatic cases may involve neck masses, dysphagia, or globus sensation—usually indicators of advanced disease.
  • "The majority of patients do not typically have symptoms at diagnosis." – Dr. Dear (02:15)
• Atypical Presentations:
  • Rarely, can initially present through distant metastases (lungs, bones) or in non-thyroidal locations due to aberrant spread.
  • "It could present as distant mets...to the lung or the bone as the initial manifestation..." – Dr. Dear (02:41)

3. Ectopic Papillary Thyroid Cancer

• Mechanism:
  • Can arise in ectopic thyroid tissue, commonly in lymph nodes, due to disrupted migration during embryogenesis.
  • Other ectopic sites: kidney, pancreas, lungs, heart.
  • "The thyroid itself can be normal, but it is, like we mentioned, very rare and it is a difficult to diagnose phenomenon." – Dr. Dear (03:38)
• Diagnosis:
  • Difficult as both primary ectopic tumors and metastases may appear in abnormal locations.

4. Usual Treatment Approaches

• Primary Modalities:
  • Risk stratification determines whether lobectomy or total thyroidectomy is chosen.
  • Lymph node involvement or metastases warrant consideration for radioactive iodine therapy.
  • Lifelong levothyroxine for TSH suppression post-operatively.
  • "The treatment options are determined by risk, stratification and extent of the disease..." – Dr. Dear (04:00)

5. Case Study: Ectopic Papillary Thyroid Cancer

Case Overview (04:38):

• Patient: 38-year-old female; non-tender, right submandibular mass noted for three months, growing in size, otherwise asymptomatic, normal labs.
• Diagnostic Pathway:
  • Head & neck ultrasound: complex cystic structure, 4.5 cm, right neck; no cervical lymphadenopathy.
  • CT scan: confirmed mass, no thyroid nodules.
  • Dedicated thyroid ultrasound: no discrete nodules.
• Biopsy Findings:
  • Fine needle aspiration: concerning for PTC.
  • Excisional biopsy: metastatic cystic papillary thyroid cancer, BRAF V600E mutation; single positive lymph node out of seven.
• Diagnostic Dilemma:
  • No evidence of primary thyroid lesion; led to suspicion of ectopic papillary thyroid cancer.
  • "We, in our differential, already included primary thyroid cancer that possibly spread to this lateral lymph node versus just a primary ectopic thyroid cancer." – Dr. Dear (06:49)
• Next Steps:
  • Recommended thyroidectomy to definitively rule out occult thyroid primary, but patient declined.
• Unresolved Diagnosis:
  • Without thyroidectomy and microscopic analysis, could not confirm whether the cancer was truly ectopic or metastatic.

6. Clinical and Patient Takeaways

• Importance of Detailed Diagnosis:
  • Accurate differentiation between metastatic and ectopic disease crucial for treatment planning and prognosis.
  • Must use thorough imaging and histopathological analysis.
  • "It's important to really diagnose the source with appropriate imaging and careful histopathologic and immunohistochemical analyses..." – Dr. Dear (08:20)
• Patient Communication:
  • Need for clear discussions around surgical options—even when rare scenarios arise.

---

Notable Quotes & Memorable Moments

• "Papillary thyroid cancer is the most common subtype of thyroid malignancy. It's actually about 80 to 85% of all thyroid cancers..." – Dr. Nikita Dear (01:08)
• "Being female is actually three times higher incidence than being a male." – Dr. Nikita Dear (01:26)
• "There have been other reports of ectopic thyroid tissue being found in the kidney, the pancreas, the lungs and the heart." – Dr. Nikita Dear (03:22)
• "We did an excisional biopsy, and it revealed a metastatic cystic papillary thyroid cancer on the pathology...and it did have a positive, positive BRAF V600E mutation." – Dr. Nikita Dear (06:17)
• "Differentiating whether it's ectopic papillary thyroid cancer from a metastatic papillary thyroid cancer is really important in determining an appropriate treatment plan..." – Dr. Nikita Dear (08:34)

---

Timestamps for Key Segments

• 00:00–01:06 – Introduction, basic facts, and risk factors for papillary thyroid cancer.
• 02:07 – Common and uncommon presentations of papillary thyroid cancer.
• 03:14 – Mechanism and rarity of ectopic papillary thyroid cancer.
• 04:00 – Overview of PTC treatment strategies.
• 04:38–07:48 – Dr. Dear’s case study: patient presentation, diagnostics, and management decisions.
• 08:20 – Key clinical takeaways for providers and patients.

---

Conclusion

This episode offers an accessible yet thorough overview of papillary thyroid cancer, underscored by a unique case of possible ectopic occurrence. Dr. Dear’s expert narrative balances clinical detail with clear explanations, making the topic approachable for both providers and informed patients. The case study exemplifies the complexity—and importance—of comprehensive diagnostic and treatment planning in thyroid cancer, especially when medical presentations deviate from the norm.

---

Transcript

[A]

Hello, I'm Aaron Lohr, and this is the Endocrine News podcast. Papillary thyroid cancer is the most common type of thyroid cancer. Yet in rare cases, this cancer may originate in locations other than the thyroid gland. Today we'll be talking about causes, prevalence, and treatment for papillary thyroid cancer and the rare phenomenon known as ectopic papillary thyroid cancer. Our guest today is Dr. Nikita Dear, Chief endocrinology fellow at the University of Texas Health Science center in Houston, Texas. Dr. Deer presented a fascinating case study at Endo2025 entitled Where is the papillary thyroid cancer? Thank you for being here today, Dr. Dear.

[B]

Thank you for having me.

[A]

So what is papillary thyroid cancer and what do we know about its causes and prevalence?

[B]

So, like you mentioned, papillary thyroid cancer is the most common subtype of thyroid malignancy. It's actually about 80 to 85% of all thyroid cancers, and it actually arises from the follicular epithelial cells, and we classify it as a well differentiated thyroid cancer. In regards to the causes of papillary thyroid cancer, it's pretty multifactorial, but one of the strongest established risk factors is exposure to ionizing radiation. Some other risk factors can include age, being female, or family history. Being female is actually three times higher incidence than being a male. In terms of prevalence, the prevalence has actually increased over the past 50 years or so, but that's likely due to increased detection from widespread use of imaging and fine needle aspiration. But despite the rising incidence incidents, the mortality rates remain pretty low.

[A]

And how does papillary thyroid cancer usually present?

[B]

Typically, when we see patients with papillary thyroid cancer, they're coming in due to an asymptomatic thyroid nodule that was discovered incidentally, either on physical exam or on an imaging study. The majority of patients do not typically have symptoms at diagnosis, but if they do, they'll have symptoms of either a palpable neck mass or they'll have some dysphagia or globus sensation. But those symptoms are usually associated with a more advanced stage.

[A]

And can papillary thyroid cancer present in an unusual manner?

[B]

Yes, it can definitely present in an unusual manner. There've been a lot of case reports of different ways that papillary thyroid cancer has presented. It could present as distant mets, metastatic lesions to the lung or the bone as the initial manifestation, rather than showing up as a nodule in the thyroid. Sometimes they can present in a location that is not the thyroid, which we're going to talk about. With my case, but there have been some case reports that have found it even in a retropharyngeal location due to unusual lymphatic spread.

[A]

How does ectopic papillary thyroid cancer usually come about?

[B]

Ectopic papillary thyroid cancer in a lymph node specifically involves a cancerous papillary thyroid cell arising from ectopic thyroid tissue within a lymph node. So during embryogenesis, thyroid tissue could be displaced due to disrupted migration. And there have been other reports of ectopic thyroid tissue being found in the kidney, the pancreas, the lungs and the heart. And then the carcinoma could develop in the ectopic thyroid tissue rather than the thyroid itself. And the thyroid itself can be normal, but it is, like we mentioned, very rare and it is a difficult to diagnose phenomenon.

[A]

And what is the typical treatment of papillary thyroid cancer?

[B]

The treatment options are determined by risk, stratification and extent of the disease. So for most patients, they'll either get a lobectomy or a total thyroidectomy. And then based on their lymph node involvement, and if there is any presence of distant metastases, radioactive iodine is considered for them. And then after everything is done, levothyroxine is used post op for TSH suppression for the rest of their life.

[A]

Now, you presented a case at end of 2025 that is quite interesting and I'm hoping you can walk us through it. Can you tell us about the patient in the study and how they presented?

[B]

The case that I presented involved a 38 year old female with no significant past medical history. She came into our clinic due to a non tender right submandibular mass. She noticed it about three months prior to her visit and had noticed that it was increasing in size. She was denying any other symptoms. No weight loss, no hypo or hyperthyroid symptoms, and all of her labs were normal.

[A]

So what were your initial thoughts and what did you do?

[B]

So when someone presents with any sort of neck mass, we're wondering, is this cancer or something benign? And so our initial steps were to do some imaging. And so we ended up getting a head and neck ultrasound. And it actually showed a complex cystic structure that was 4.5 cm in the right side of the neck. But there was no evidence of any cervical lymphadenopathy. Once we saw that, we decided to get a CT scan of the neck to better characterize that area. And it didn't show any thyroid nodules, but it did confirm the complex right neck level to A mass or lymph node is what the rheologists read it as, with an enhancing solid component and a thin wall cystic component. We then decided to do a dedicated thyroid ultrasound to make sure that there was nothing else going on in the thyroid, but it did not reveal any discrete thyroid nodules.

[A]

So you didn't find anything in the thyroid. You had the mass. So what did you decide to do next?

[B]

Since we had located the mass, we decided to do a fine needle aspiration. And so that was done, and it showed concerns for papillary thyroid cancer. Following that, we did an excisional biopsy, and it revealed a metastatic cystic papillary thyroid cancer on the pathology. It was 2.5 cm in the largest dimension, and there was no extranodal extension. They did show that one out of the seven lymph nodes that were collected were positive, and it did have a positive, positive BRAF V600E mutation.

[A]

So when did you begin to suspect ectopic papillary thyroid cancer?

[B]

So it was at this time, after we got the finite aspiration of the mass, that we were beginning to suspect ectopic parathyroid cancer. We, in our differential, already included primary thyroid cancer that possibly spread to this lateral lymph node versus just a primary ectopic thyroid cancer.

[A]

When and how did you get a clearer picture as to what was going on?

[B]

This biopsy really helped us identify that it was a papillary thyroid cancer. That's what we were concerned about. The next steps we actually wanted to do for this patient was thyroidectomy, because the only way to really confirm whether this is metastatic thyroid cancer versus an ectopic papillary thyroid cancer is to remove the thyroid, make sure under the microscope that it doesn't show any signs of thyroid cancer, and then we can fully confirm that this is completely ectopic in the lymph node and was not primary from the thyroid itself.

[A]

What were the next steps for the patient?

[B]

We discussed this option with the patient about doing the surgery. However, she actually was not interested in doing the thyroid surgery. She felt uncomfortable doing that, and so we have not been able to confirm that with a diagnosis. Looking at the thyroid under the microscope.

[A]

Given that ectopic papillary thyroid cancer is such a rare phenomenon, what do healthcare providers and patients need to know about it?

[B]

It's important to really diagnose the source with appropriate imaging and careful histopathologic and immunohistochemical analyses to determine what is the cancer that is in place and whether the source is primary versus metastatic versus ectopic and differentiating whether it's ectopic papillary thyroid cancer from a metastatic papillary thyroid cancer is really important in determining an appropriate treatment plan and then providing the patient with an appropriate prognosis as well.

[A]

Well, I want to thank you, Dr. Deer, for coming to the podcast and sharing your case study helping us better understand papillary thyroid cancer and when it gets unusual sometimes. So thank you so much for being on the podcast.

[B]

Thank you for having me.

[A]

That's all for this episode. I hope you enjoyed hearing from Dr. Dear about her case involving ectopic papillary thyroid cancer. I think case studies like this are intriguing and I often wonder, should we have more of these featured on the podcast? What do you think? Do you want to hear more? Maybe something else? Let me know by emailing [e-mail] we'll be back soon with another fascinating dive into the world of endocrinology. Until then, thanks for listening. Endocrine News Podcasts are a free service of the Endocrine Society. To learn more or to become a member, visit the society's website at www.endocrine.org.