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.