Definitions

Thyroid gland
ICD-O-3 topography code:	C73
ICD10:	C73

A primary carcinoma of the thyroid gland containing a medullary carcinoma component that is immunohistochemically positive for calcitonin, and follicular cell carcinoma structures that are immunohistochemically positive for thyroglobulin.
Mixed medullary and follicular cell carcinoma of the thyroid gland are very rare tumours and most have been described in single case reports ¹

Click to access Pubmed

Papotti M, Negro F, Carney JA, Bussolati G, Lloyd RV (1997)
Mixed medullary-follicular carcinoma of the thyroid. A morphological, immunohistochemical and in situ hybridization analysis of 11 cases.
Virchows Arch 430: 397-405

. The mean age of 36 reported cases was 48 years ²

Click to access Pubmed

Papotti M, Volante M, Komminoth P, Sobrinho-Simões M, Bussolati G (2000)
Thyroid carcinomas with mixed follicular and C-cell differentiation patterns.
Semin Diagn Pathol 17: 109-19

, not differing from conventional medullary carcinoma, with a 1.3:1 male to female ratio ³

Ronald A. DeLellis, Ricardo V. Lloyd, Philipp U. Heitz, Charis Eng
World Health Organization Classification of Tumours. Pathology and Genetics of Tumors of Endocrine Organs
IARC Press: Lyon 2004

.