Malignant carcinoid tumor of the thymus

This code signifies a rare neuroendocrine tumor originating in the thymus gland, characterized by its malignant nature. These tumors arise from enterochromaffin-like cells and can produce hormones, leading to carcinoid syndrome in some cases.

Apply this code when documentation explicitly states a diagnosis of a malignant carcinoid tumor located within the thymus. Supporting documentation should include pathology reports confirming the tumor type and its primary site, along with imaging studies or clinical notes indicating the thymic origin.

• Ensure the pathology report specifies "malignant" to differentiate from benign carcinoid tumors.
• Verify the primary site is definitively the thymus; do not use for metastatic carcinoid to the thymus.
• Consider additional codes for any associated carcinoid syndrome manifestations (e.g., diarrhea, flushing).