IMMUNOHISTOCHEMISTRY, CALCITONIN

What this test checks

Detects calcitonin hormone in thyroid tissue to confirm medullary thyroid carcinoma (MTC) — a rare type of thyroid cancer arising from parafollicular C-cells that produce calcitonin.

Why do people get this test?

Medullary thyroid carcinoma is genetically distinct from other thyroid cancers and requires different surgery and family screening. Calcitonin IHC confirms the diagnosis definitively from tissue.

When you should consider this test

• When a thyroid tumour is suspected to be medullary thyroid carcinoma
• When classifying thyroid nodules or tumours
• When MEN2 syndrome (multiple endocrine neoplasia) is being evaluated

How to prepare

No preparation needed — performed on biopsy or surgical tissue.