C73
BillableMalignant neoplasm of thyroid gland
HCC Category Mapping
V28HCC 23 — Melanoma and Other Skin Cancers
0.251V24HCC 12 — Breast, Prostate, and Other Cancers and Tumors
0.150ESRDHCC 12 — Breast, Prostate, and Other Cancers and Tumors
0.000RxHCCHCC 22 — Cancer, Other Specified Sites
0.000What This Code Means
Cancer that develops in the thyroid gland, a butterfly-shaped gland in the neck that produces hormones regulating metabolism.
Coding Tips
- •This code does not differentiate between histological types (papillary, follicular, medullary, anaplastic); review pathology reports for histology if needed for treatment planning
- •Ensure documentation specifies thyroid gland involvement and not metastatic disease to the thyroid from another primary site
Clinical Significance
Malignant neoplasm of the thyroid gland is one of the more common endocrine malignancies, with papillary thyroid carcinoma being the most prevalent subtype. Despite generally favorable prognosis for well-differentiated types, this diagnosis carries meaningful risk adjustment weight and requires lifelong surveillance with thyroid function monitoring and cancer recurrence screening. Accurate coding distinguishes active malignancy from personal history of thyroid cancer.
Documentation Requirements
- ✓Pathology report confirming malignancy with histological type (papillary, follicular, medullary, anaplastic, or poorly differentiated)
- ✓Current status — active disease vs. in remission vs. history of (Z85.850 for personal history)
- ✓Staging information (TNM staging) when available
- ✓Treatment status — post-thyroidectomy, radioactive iodine therapy, current surveillance
- ✓Thyroglobulin levels and thyroid function tests supporting ongoing monitoring
Use Additional Code
- code to identify any functional activity
Commonly Confused Codes
Z85.850 — Personal history of malignant neoplasm of thyroid: Use when cancer is resolved/in remission with no evidence of disease, not during active treatmentD34 — Benign neoplasm of thyroid gland: Thyroid adenomas and benign nodules are not malignantE04.1 — Nontoxic single thyroid nodule: Thyroid nodules are not automatically malignantD44.0 — Neoplasm of uncertain behavior of thyroid gland: Use when malignancy is not yet confirmedC79.89 — Secondary malignant neoplasm of other specified sites: Metastatic cancer TO the thyroid from another primary
Code Hierarchy
└C73Malignant neoplasm of thyroid gland
└C73Malignant neoplasm of thyroid gland