Malignant neoplasm of thyroid gland

This code signifies the presence of a cancerous tumor originating in the thyroid gland. This malignancy can affect various cell types within the thyroid, leading to different histological classifications. It represents a primary malignant growth rather than a metastatic lesion from another site.

Utilize this code when documentation clearly indicates a primary malignant neoplasm of the thyroid gland. This includes confirmed diagnoses from pathology reports, operative reports detailing thyroidectomy for malignancy, or physician notes explicitly stating thyroid cancer. Ensure the documentation specifies the thyroid as the primary site.

• Always seek the most specific subcategory for the type of thyroid cancer (e.g., papillary, follicular, medullary) if documented.
• Do not use this code for secondary malignant neoplasms (metastatic cancer) to the thyroid; use C79.89.
• Sequence this code as the primary diagnosis when the patient is receiving active treatment for the thyroid malignancy.