Malignant neoplasm of parathyroid gland

This code identifies a primary cancerous tumor originating in one of the parathyroid glands. These glands, typically four in number and located in the neck near the thyroid, are responsible for regulating calcium levels in the blood. A malignant neoplasm in this location indicates an uncontrolled growth of abnormal cells with the potential to invade surrounding tissues or metastasize.

Assign this code when documentation confirms a primary malignant neoplasm of the parathyroid gland. This typically follows a biopsy and pathological confirmation of malignancy. It is used for initial diagnosis, treatment, and ongoing management of the primary parathyroid cancer.

• Always confirm the primary nature of the malignancy; do not use for metastatic disease to the parathyroid.
• Distinguish from benign parathyroid adenomas (D35.1) or hyperplasia (E21.0), which are much more common.
• Sequence as the primary diagnosis when the parathyroid malignancy is the reason for the encounter, followed by any associated conditions or complications.