Levels of serum calcitonin could be a useful biomarker and improve surgical planning in patients with medullary thyroid carcinoma (MTC) with indeterminate cytology, according to a new study published in the ANZ Journal of Surgery.

Studies show that the diagnosis of MTC is very difficult prior to surgery. Here, a team of researchers from Monash University Endocrine Surgery Unit, Alfred Hospital in Melbourne, Victoria, Australia led by James C. Lee, MBBS, FRACS, PhD, aimed to identify areas that may be improved when evaluating patients with MTC preoperatively.

The researchers recruited 1454 patients with thyroid cancer between 2000 and 2020 from the Monash University Endocrine Surgery Unit database.

Continue Reading

Read more about MTC diagnosis

Of these, 43 (3%) had MTC, 6 of these patients (14%) had high levels of serum calcitonin preoperatively, and the majority of them (86%) had an optimal thyroidectomy and lymph node dissection. In contrast, 5 patients (14% of all those with MTC had less than total thyroidectomy due to nerve injury while 34 had compartmental lymph node dissection.

A total of 12 patients had indeterminate or nondiagnostic cytology. Of those, 5 had increased serum calcitonin levels and were treated with thyroidectomy and lymph node dissection. The other 7 patients did not have lymph node dissection and therefore were considered to have had suboptimal surgery.

“Our findings reflect the rarity of MTC, and the challenges of pre-operative diagnosis,” wrote the authors of the study. “From an observational standpoint, [serum calcitonin] improves pre-operative evaluation of MTC presenting as indeterminate cytology and aids operative planning.”

MTC is a rare type of neuroendocrine tumor of the thyroid gland, accounting for 2% to 4% of all thyroid cancer cases. MTC arises from the parafollicular cells, which secrete high levels of calcitonin.


Jassal K, Ravintharan N, Prabhakaran S, Grodski S, Serpell JW, Lee JC. Preoperative serum calcitonin may improve initial surgery for medullary thyroid cancer in patients with indeterminate cytology. ANZ J Surg. Published online April 12, 2022. doi:10.1111/ans.17690