Radiology Coding Alert

Question: A patient diagnosed with hyperthyroidism was found to have an additional single thyroid nodule during a thyroid ultrasound. The radiologist did not specify that it was a goiter. What ICD-10 code(s) would we apply?

New York Subscriber

Answer: A single thyroid nodule, on its own, codes as E04.1 (Nontoxic single thyroid nodule). However, you will want to factor in the diagnosis of hyperthyroidism. You can try to use the ICD-10 index by searching Nodule à Thyroid à Toxic or with hyperthyroidism à E05.20 (Thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm). As you see in the code descriptor, however, this is not the correct ICD-10 code based on the reference of a multinodular goiter.

If you take a step back and look at the E05.- code list, you will see that the correct option exists in code E05.10 (Thyrotoxicosis with toxic single thyroid nodule without thyrotoxic crisis or storm).

Beware: If you search for this diagnosis using the term “nodule” as your primary search keyword, you will be directed to E05.20 via the ICD-10 index. However, if you use “hyperthyroidism” as the primary search term, you will be directed to E05.10.

For clarity: The term “goiter,” as defined by The American Thyroid Association, “refers to the abnormal enlargement of the thyroid gland.” By this definition, the description of a simple thyroid nodule meets the criteria for a goiter. However, ICD-10 coding relies exclusively on the wording of the diagnosis. So even if some words have interchangeable meanings, it’s important not to code a particular symptom or disease if the index does not lead you directly to it.

Take note: A documented thyroid lesion does not necessarily imply the presence of a nodule or goiter. While, some coders are inclined to code “thyroid lesion” using E04.1 or E04.9 (Nontoxic goiter, unspecified), these would be incorrect. Instead, you will want to use E07.9 (Disorder of thyroid, unspecified) for thyroid lesions without any additional descriptive information.