Epithelial tumors of thyroid gland concern more than 90 % of all malignancies

Follicular cells carcinomas :

• Differentiated
  • Papillary carcinoma
  • Follicular carcinoma
• Poorly differentiated : insular type
• Indifferentiated (anaplastic) carcinoma

C cell carcinoma : medullary thyroid carcinoma (MTC)

• Sporadic form (70 -80%)
• Familial form
  • Isolated MTC
  • Associated with MEN II A or B

Papillary carcinoma variants :

• Papillary Microcarcinoma : size < 1cm (mostly < 0,5cm)
• Encapsulated Papillary Carcinoma
• Pure Follicular variant
• Solid/trabecular variant
• Diffuse sclerosing variant
• Tall cell variant
• Columnar cell variant
• Oncocytic variant with lymphoid stroma " Warthin like tumor"

Follicular Carcinoma variants :

• classical type
• oxyphilic cell
• clear cell

Anatomic forms :
  - minimally invasive or encapsulated
  - widely invasive

Staging TNM of Thyroid Tumors (UICC) 1997

I - Primary tumor (T= clinic ou pT = histopathologic)

• pT0 :  no evidence of primary tumor
• pT1 :  tumor 1 cm or less in greater dimension, intra-thyroid
• pT2 :  tumeur less than 1cm but no more 4 cm in greater dimension, intra-thyroid
• pT3 : tumeur more than 4 cm in greater dimension, intra-thyroid
• pT4 : tumor of any size extending beyond the thyroid capsule.

Note : all categories can be subdivided into :
            (a) solitary tumor
            (b) multifocal tumor

II - Regional lymph nodes (N ou pN)

• pN0 : no regional lymph node
• pN1 : regional lymph node metastasis
  • N1a : ipsilateral
  • N1b : bilatéral, midline or controlateral cervical or mediastinal lymph nodes

III - Metastasis (M ou pM)

• pM0 : no metastasis
• pM1 : distant metastase.

References :

GENERAL :

HEDINGER C., WILLIAMS E.D., SOBIN L.H. - Histological typing of thyroid tumours - Internation histological classification of tumors, World Health Organisation, Berlin, Heidelberg, New York. Springer Verlag 1988, Second Edition

LI VOLSI V.A.
Surgical Pathology of the Thyroid.
Major problems in Pathology - vol. 22 - p. 328-330, 333-335
Philadelphie - WB Saunders Company - 1990

ROSAI J., CARCANGIU M.L., DELELLIS R.A.
Tumors of the thyroid gland. Third series, Fascicle 5. Washington D.C.,
Armed Forces Institute of Pathology, 1992.

UICC (International Union Against Cancer) : TNM Classification of Malignant Tumours (4th fully rev. ed.), P. HERMANEK, L.H. SOBIN, eds, Berlin, Springer-Verlag, 1997.

PRONOSTIC :

Asklen LA, LiVOLSI VA : Pronostic significance of histologic grading compared with subclassification of papillary thyroid carcinoma
Cancer 2000 ; 88 : 1902 - 1908

HAY I.D., BERGSTRALH E.J., GOELLNER J.R., EBERSOLD J.R. - Predicting outcome in papillary thyroid carcinoma : development of a reliable pronostic scoring system in a cohort of 1779 patients surgically treated at one institution during 1940 through 1989.
Surgery 1993 ; 114 : 1050-1058.

LECLERE J, KLEIN M
Les facteurs pronostiques dans les cancers différenciés de la thyroïde (médullaire exclus)
Ann. Endocrinol (Paris), 1997, 58, 183-187 (très bonne revue des différents systèmes d'histopronostic AGES - AMES - MACIS EORTC ....)