- Human pathology

Home > E. Pathology by systems > Endocrine system > Thyroid gland > thyroid tumors

thyroid tumors

Monday 5 July 2004

tumors of the thyroid gland


I. Thyroid epithelial tumours

A. Thyroid tumors of follicular or metaplastic epithelium

- thyroid follicular tumors

- thyroid papillary tumors

  • thyroid papillary carcinoma (TPC)
  • thyroid papillary microcarcinoma
  • follicular variant of thyroid papillary carcinoma (TPC)
  • diffuse sclerosing variant of thyroid papillary carcinoma (TPC)

- thyroid undifferentiated tumors (thyroid anaplastic tumors )
- thyroid poorly differentiated thyroid carcinoma
- thyroid columnar cell carcinoma
- thyroid mucoepidermoid carcinoma

- others thyroid adenomas

  • hyalinizing trabecular adenoma

B. Tumors showing c-cell differentiation

- thyroid medullary carcinoma

C. Tumors showing both follicular and C-cell differentiation

- mixed medullary-follicular carcinoma

D. Thymic and related branchial pouch tumors of the thyroid

- SETTLE (spindle epithelial tumor with thymus-like differentiation )

II. mesenchymal tumors of the thyroid

III. thyroid lymphomas

IV. Miscellaneous tumours


- thyroid carcinomas

  • thyroid papillary carcinoma

- Hurthle cell tumors

  • Hurthle cell thyroid carcinoma

- C-cell tumors

  • C-cell hyperplasia
  • medullary thyroid carcinoma (MTC)
    • microscopical medullary thyroid carcinoma (microMTC)

WHO 2017 Classification / Modified Version of WHO Classification of Nonmedullary Thyroid Tumors 2017

I. Epithelial Tumors
A. Follicular cell neoplasms
Benign follicular tumors
Follicular adenoma
Hyalinizing trabecular tumor
Hürthle cell adenoma
Borderline follicular tumors/encapsulated or well-circumscribed
follicular-pattemed tumors with well-developed or equivocal
nuclear features of papillary thyroid carcinoma
Papillary carcinoma
Follicular carcinoma
Hürthle carcinoma
Poorly differentiated carcinoma
Anaplastic (undifferentiated) carcinoma
Squamous cell carcinoma.

B. Other epithelial tumors
Salivary gland—type carcinomas
Mucoepidermoid carcinoma
Sclerosing mucoepidermoid carcinoma with eosinophilia
Mucinous carcinoma
Thymic tumors
Ectopic thymoma
Intrathyroid epithelial thymoma/CASTLE
Spindle epithelial tumor with thymus-like differentiation

Variants of Papillary Thyroid Carcinoma PTC

1. Conventional/classic
2. Papillary microcarcinoma
3. Encapsulated
4. Follicular
5. Diffuse sclerosing
6. Tall cell
7. Columnar cell
8. Cribriform-morular
9. Hobnail
10. Papillary thyroid carcinoma with fibromatosis/fascitiis-like stroma
11. Solid/trabœular variant
12. Oncocytic
13. Spindle cell
14. Clear cell variant
15. Warthin like variant

The histologie criteria for poorly differentiated carcinoma are :
- (1) a diagnosis of carcinoma of follicular cell derivation (by conventional criteria);
- (2) solid, insular, or trabecular growth;
- (3) absence of conventional nuclear features of papillary thyroid carcinoma; and
- (4) at least 1 of 3 features: convoluted nuclei (ie, "dedifferentiated" nuclear features of papillary carcinoma), mitotic activity 3 or more per 10 high-power fields, or tumor necrosis.

An algorithmic approach is needed for practical use to diagnose this carcinoma.

See also

- thyroid tumorigenesis