C cell hyperplasia.
The evidence that C cell hyperplasia is the precursor of medullary carcinoma in families where this tumour is inherited is very strong. It is suggested that the tumour is the result of at least two mutations, in the families with medullary carcinoma the first of these is genetically determined, and the second is an acquired somatic mutation, in the sporadic tumour both are acquired somatic mutations. The recognition of hyperplasia as the premalignant lesion in genetically determined cases is important to patient management. Identification of C cell hyperplasia by the pathologist should lead to family studies. The ideal investigation and treatment of potentially affected members of medullary carcinoma families is the identification of affected members at the stage of C cell hyperplasia so that total thyroidectomy can be carried out before the development of a malignant and potentially lethal tumour.
D000328:Adult; D002277:Carcinoma / Q000235:genetics / Q000473:pathology*; D006801:Humans; D006965:Hyperplasia; D008875:Middle Aged; D009377:Multiple Endocrine Neoplasia / Q000235:genetics*; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology*