Papillary
By far the most common type, making up roughly 8 in 10 thyroid cancers. Slow-growing and well differentiated, it carries an excellent prognosis. Read more on our papillary thyroid cancer page.
Understanding your thyroid cancer type
Differentiated vs undifferentiated thyroid cancer — what it means for you
Medically reviewed by Dr. Owais Mohammed, Medical Oncologist, MBBS · MD · Last reviewed June 2026
When thyroid cancer is diagnosed, one of the first things your report describes is whether it is differentiated or undifferentiated. This simply describes how closely the cancer cells still resemble normal thyroid tissue — and it shapes the prognosis and the treatment plan. Understanding the difference helps you take the next step calmly.
- Differentiated thyroid cancer — cells look like normal thyroid; slow-growing, excellent outlook
- Undifferentiated (anaplastic) — rare and aggressive; needs urgent, coordinated care
- Most are well differentiated — papillary, follicular and Hürthle cell cancers
- The type guides the plan — a tumour board confirms which you have before treating
17+
Cancer Specialists
on Panel
on Panel
96.9%
Breast Cancer
Survival Rate*
Survival Rate*
15,000+
Patients
Treated
Treated
4.8★
Google Rating
(800+ reviews)
(800+ reviews)
What "Differentiated" and "Undifferentiated" Mean
The thyroid is a small, butterfly-shaped gland at the base of the neck that controls how your body uses energy. When thyroid cancer is found, pathologists look at the cancer cells under a microscope and describe how closely they still resemble normal thyroid tissue. That single observation is what the words differentiated and undifferentiated describe.
Differentiated thyroid cancer (DTC) means the cells still look and behave much like normal thyroid cells. The term well differentiated thyroid cancer describes exactly this — cells that keep their normal features. Because of that, these cancers tend to grow slowly, can still take up iodine, and respond very well to treatment. They make up the large majority of all thyroid cancers.
Undifferentiated thyroid cancer — also called anaplastic thyroid cancer — means the cells have lost the features of normal thyroid tissue. The undifferentiated meaning here is important: cells this abnormal grow quickly and behave aggressively, so this type is rare but needs urgent, specialist care.
If you have just been given one of these labels, the most important thing to know is that the type guides the plan. A clear diagnosis is the start of a well-mapped pathway — not a reason to panic. We walk this journey with you, one step at a time.
Did you know?
The large majority of thyroid cancers are differentiated — papillary alone accounts for roughly 8 in 10 cases — while undifferentiated (anaplastic) cancer is rare, making up only a small fraction of thyroid cancers. (Source: NCCN Clinical Practice Guidelines in Oncology — Thyroid Carcinoma; American Cancer Society.)
Well differentiated thyroid cancer
Most common
Second most common
Less common variant
The contrast
The Differentiated Types of Thyroid Cancer
Three main types of thyroid cancer are differentiated. All start in the follicular cells of the thyroid, grow slowly, and usually respond well to surgery and, where needed, radioactive iodine. Your pathology report will name which one you have.
Follicular
The next most common differentiated type. It is also well differentiated and slow-growing, and usually responds well to surgery and radioactive iodine, with a favourable outlook.
Hürthle cell
A less common variant counted as differentiated. It is treated along similar lines, though it is watched a little more closely and may take up iodine less readily than other types.
Undifferentiated (anaplastic)
Set apart from the above. Its cells have lost their normal features, so it grows quickly and no longer takes up iodine. Rare, but it needs urgent, coordinated specialist care.
Why the Differentiated vs Undifferentiated Distinction Matters
This is not just a label on a report — it is one of the most important early facts about your cancer, because it shapes both the likely outlook and the treatment plan.
It shapes the prognosis. Well differentiated thyroid cancers grow slowly and respond well to treatment, so the great majority of patients do very well. Undifferentiated cancer is more serious and is managed with greater urgency.
It shapes the treatment. Because differentiated cells still take up iodine, radioactive iodine (RAI) therapy can be used after surgery. Undifferentiated cancer does not take up iodine, so its treatment combines surgery, radiation and systemic therapy instead.
Because the two are managed so differently, confirming which category you have is essential before any treatment begins. Speak to a CION thyroid cancer specialist to understand what your own report means.
12+ Centres in Hyderabad · Pick yours
CION cancer care is closer than you think.
We're never more than 30 minutes away. Same panel of specialists at every centre. Same tumour board reviews. Same NCCN protocols. Pick the closest one and call directly — or let us pick for you.
CION Ameerpet
CION Kukatpally
CION L.B. Nagar
CION Tolichowki
CION Masab Tank
CION Banjara Hills
CION Kompally
CION Balanagar
CION Siddipet
CION Sangareddy
Not sure which centre fits best? Tell us where you are — we'll suggest the closest one with the right specialists.
Help me pick the right centre
Beyond Hyderabad
35+ centres across Telangana & Andhra Pradesh
Travelling for treatment? We may have a centre right where you are.
Telangana
Andhra Pradesh
Don't see your city? Call 18002028726 — we'll find your nearest CION partner centre.
Meet the Specialists
17+ senior cancer specialists. One panel for your case.
Trained at AIIMS, Tata Memorial, and leading international centres. Combined 150+ years of experience. Every complex case is reviewed by 3+ of them — together.
Medical Oncologist
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Surgical Oncologist
Dr. Muralidhar Muddusetty
MBBS (AIIMS), MS (Surgery) (AIIMS), DNB (Surgical Oncology), MRCS (Edinburgh)
Surgical Oncologist
Surgical Oncologist
Surgical Oncologist
Dr. Vinay Mamidala
MBBS, MS(General Surgery), M.Ch(Surgical Oncology), FMAS, FARIS(Ongoing)
Surgical Oncologist
Radiation Oncologist
Radiation Oncologist
Radiation Oncologist
Hematologist
Interventional Radiologist
Dr. Mohammed Imran
Surgical Oncologist
Dr. Vajja Sandeep Kumar
MBBS, MS (General Surgery), DrNB (Surgical Oncology), FALS Oncology
Surgical Oncologist
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
Know Exactly What Your Diagnosis Means
Differentiated or undifferentiated, the right plan is the one made for you, by a team. We give you a 45-minute consultation, a tumour-board review, and no unnecessary tests.
Side by side
Differentiated vs Undifferentiated — A Clear Comparison
This table summarises the main differences. It is a general guide; your own outlook and plan are confirmed by a tumour board after reviewing your reports.
| Differentiated (DTC) | Undifferentiated (Anaplastic) | |
|---|---|---|
| What the cells look like | Still resemble normal thyroid cells — "well differentiated" | Have lost the features of normal thyroid tissue |
| Main types | Papillary, follicular, Hürthle cell | Anaplastic thyroid cancer |
| How common | The large majority of thyroid cancers | Rare — a small fraction of thyroid cancers |
| How it grows | Usually slow-growing | Fast-growing and aggressive |
| Takes up iodine? | Yes — so radioactive iodine (RAI) can be used | Usually no — RAI is not effective |
| Main treatments | Surgery, selective RAI, thyroid hormone tablets | Surgery where feasible, radiation, systemic therapy |
| General outlook | Excellent — most patients do very well | More serious — needs urgent, coordinated care |
Did you know?
Because differentiated thyroid cancer cells still take up iodine, radioactive iodine (RAI) therapy can target leftover thyroid cells after surgery — a treatment that does not work for undifferentiated cancer, where the cells no longer absorb iodine. (Source: NCCN Clinical Practice Guidelines in Oncology — Thyroid Carcinoma.)
Treatment differs by type
How Each Type Is Treated
Because the two cancers behave so differently, they are treated differently. In every case at CION, a tumour board agrees the plan, so treatment is matched precisely to the type of cancer you have.
Surgery (thyroidectomy)
The main treatment for differentiated cancer — a lobectomy or total thyroidectomy. Surgery is also used for undifferentiated cancer where the tumour can be safely removed.
Radioactive iodine (RAI)
Used selectively for differentiated cancer, because those cells still take up iodine. It is not effective for undifferentiated cancer, whose cells no longer absorb iodine.
Radiation & systemic therapy
Central to treating undifferentiated cancer — radiation plus systemic therapy such as targeted or chemotherapy drugs, delivered urgently by a multidisciplinary team.
Thyroid hormone tablets
After surgery for differentiated cancer, most patients take a daily thyroid hormone tablet. At the right dose it replaces normal function and helps lower the chance of return.
The exact plan depends on the type, size and spread of your cancer — confirmed at thyroid cancer staging and agreed by a tumour board.
Confirming Whether It Is Differentiated or Undifferentiated
The category is decided by examining cells or tissue under a microscope — not by symptoms alone. Getting this right is the foundation of a correct treatment plan.
Ultrasound and FNAC. It usually begins with a neck ultrasound and a fine needle aspiration cytology (FNAC) — a quick outpatient test that samples cells from the thyroid nodule with a very thin needle. A pathologist then studies how closely the cells resemble normal thyroid tissue.
Confirmed after surgery, where needed. Sometimes the full picture, including the exact type, is confirmed once the whole specimen can be examined after surgery. At CION, the findings are reviewed by a tumour board before the plan is finalised.
If you already have a report, a free written second opinion can confirm the type and explain it clearly. Book a free review and take the next step with a team beside you.
Why Patients Choose CION to Understand Their Diagnosis
If you want your diagnosis understood properly — and treated with exactly the right amount of care, no more and no less — here is what to expect at CION.
- Free 45-minute consultation — unhurried time to explain your report and answer every question
- Tumour board for every patient — your plan is agreed by a team, not one doctor's opinion
- No unnecessary tests or treatment, ever — RAI and extra scans are used only when they genuinely help
- Care led by a team — medical, surgical and radiation oncologists working together
- 35+ centres across Telangana & AP — care close to home, with less travel
- Free written second opinion — bring an existing report and have the type reviewed at no cost
Whatever your report says, understanding it is the first step. Book a free consultation and walk the journey with a team beside you.
From our patients
People Treated for Thyroid Cancer — and What Happened Next
Real stories from patients who were newly diagnosed, got a clear plan, and walked the journey with our team.
Real Stories. Real Voices.
15,000+ patients chose CION. Hear from them directly.
These aren't paid endorsements or written reviews. These are video testimonials from real patients and families — recorded on their own phones, in their own words. Pick any one. Watch it. Then decide.
4.8★800+ Google reviews
50+video testimonials
15,000+patients treated
Read all 800+ reviews on Google
Start Your Story. Book Free Consultation.
Common questions
Differentiated vs Undifferentiated Thyroid Cancer — Your Questions Answered
What is the difference between differentiated and undifferentiated thyroid cancer?
The difference is how closely the cancer cells still resemble normal thyroid cells. In differentiated thyroid cancer, the cells look and behave much like healthy thyroid tissue — they grow slowly and usually respond very well to treatment. In undifferentiated thyroid cancer, also called anaplastic cancer, the cells have lost these normal features, so the cancer grows quickly and behaves more aggressively. Differentiated cancers make up the large majority of thyroid cancers and carry an excellent outlook, while undifferentiated cancer is rare and needs urgent, specialist care. Your pathology report will state which category your cancer falls into.
What does well differentiated thyroid cancer mean?
Well differentiated thyroid cancer means the cancer cells, when viewed under a microscope, still look very similar to normal thyroid cells and keep many of their normal functions. This is a reassuring finding. Because the cells behave much like healthy tissue, the cancer tends to grow slowly and, importantly, can still take up iodine — which makes radioactive iodine (RAI) therapy a useful treatment. Papillary, follicular and Hürthle cell carcinomas are all well differentiated thyroid cancers. The great majority of thyroid cancers are well differentiated, and they carry one of the most favourable prognoses of any cancer.
Which thyroid cancers are differentiated?
Three main types of thyroid cancer are differentiated: papillary thyroid cancer, follicular thyroid cancer and Hürthle cell carcinoma. Papillary is by far the most common, accounting for roughly 8 in 10 thyroid cancers. Follicular is the next most common. Hürthle cell carcinoma is a less common variant that is also counted as differentiated. All three start in the follicular cells of the thyroid, grow slowly, and usually respond well to surgery and, where needed, radioactive iodine. Together they make up the large majority of all thyroid cancers.
What is undifferentiated (anaplastic) thyroid cancer?
Undifferentiated thyroid cancer, also called anaplastic thyroid cancer, is a rare and aggressive type in which the cancer cells have lost the features of normal thyroid tissue. Because the cells are so abnormal, the cancer grows quickly and can spread early, which is why it needs urgent assessment by a specialist team. It usually no longer takes up iodine, so radioactive iodine therapy is not effective, and treatment instead combines surgery where feasible, radiation and systemic therapy. Although it is far less common and more serious than differentiated cancer, a fast, coordinated, multidisciplinary plan is essential and gives every patient the best chance.
Is differentiated thyroid cancer more or less serious than undifferentiated?
Differentiated thyroid cancer is far less serious than undifferentiated thyroid cancer. Differentiated cancers — papillary, follicular and Hürthle cell — grow slowly, respond very well to treatment, and carry an excellent prognosis, with the great majority of patients cured. Undifferentiated, or anaplastic, cancer is rare but much more aggressive: it grows quickly and is harder to treat, which is why it needs urgent specialist care. The two are treated very differently, so confirming which category you have is one of the most important early steps. A clear diagnosis, made by a tumour board, guides the right plan for your situation.
How are differentiated and undifferentiated thyroid cancer treated differently?
The treatments differ because the two cancers behave so differently. Differentiated thyroid cancer is usually treated with surgery — a lobectomy or total thyroidectomy — followed, when needed, by selective radioactive iodine (RAI) therapy and daily thyroid hormone tablets. Because the cells still take up iodine, RAI works well. Undifferentiated thyroid cancer does not respond to RAI, so its treatment combines surgery where feasible, radiation therapy and systemic therapy such as targeted or chemotherapy drugs, delivered urgently by a multidisciplinary team. In every case at CION, a tumour board agrees the plan, so treatment is matched precisely to the type of cancer you have.
Can differentiated thyroid cancer become undifferentiated?
Rarely, a long-standing or untreated differentiated thyroid cancer can change over time into a more aggressive, undifferentiated form — a process doctors call dedifferentiation. This is uncommon, but it is one of the reasons why a confirmed diagnosis and an appropriate, timely treatment plan matter. It is also why follow-up after treatment is important. For most people with differentiated thyroid cancer, the outlook stays excellent and this change never happens. If you are worried about your diagnosis, an unhurried specialist review can explain exactly what your reports mean and what the right next step is.
How is the type of thyroid cancer confirmed?
The type of thyroid cancer — whether differentiated or undifferentiated — is confirmed by examining cells or tissue under a microscope. It usually begins with a neck ultrasound and a fine needle aspiration cytology (FNAC), a quick test that samples cells from the thyroid nodule with a very thin needle. A pathologist then studies the cells to see how closely they resemble normal thyroid tissue, which determines the category and the exact type. Sometimes the full picture is confirmed after surgery, when the whole specimen can be examined. At CION, the findings are reviewed by a tumour board before any treatment plan is finalised.
Should I get a second opinion on my thyroid cancer type?
A second opinion is always reasonable, especially because the type of thyroid cancer guides the entire treatment plan and the two categories are managed very differently. If you have an ultrasound, FNAC or biopsy report, it is worth having it reviewed by an experienced oncology team so you fully understand what it means. At CION we offer a free written second opinion: bring your existing reports and we will explain them clearly, in plain language, with no rushed decisions and no unnecessary tests. Understanding your diagnosis properly is the first step to choosing the right care.
Disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified oncologist for guidance specific to your situation. This page is periodically reviewed and updated by CION's medical team in line with current clinical guidelines.
Explore more
Thyroid Cancer Topics
Browse our complete guide to thyroid cancer — types, symptoms, causes, tests, stages and treatment. Tap any topic to read more.
Treatment & Specialist Care
Types of Thyroid Cancer
Symptoms & Warning Signs
Causes & Risk Factors
Tests & Diagnosis
Stages, Survival & Prognosis
Treatment & Procedures
Thyroidectomy Surgery
Thyroid Lobectomy
Neck Dissection
Radioactive Iodine (RAI)
Low-Iodine Diet for RAI
Targeted Therapy
External Beam Radiation
Does It Need Chemotherapy?
Treatment Without Surgery
Active Surveillance
Hormone Replacement & TSH
RAI-Refractory Disease
Anaplastic Cancer Treatment
Treatment Side Effects