Ultrasound-guided thyroid fine-needle aspiration is a reliable method for detecting medullary thyroid carcinoma (MTC) before surgery, according to a new study published in the Journal of Immunoassay and Immunochemistry. It can therefore also facilitate the management of these patients.
Fine-needle aspiration biopsy is part of the diagnostic workup for MTC. Here, a team of researchers presented their experience using ultrasound-guided fine-needle aspiration and liquid-based cytology (LBC), and immunocytochemistry (ICC) to diagnose MTC.
The team searched their laboratory archives for thyroid fine-needle aspiration that led to a diagnosis of MTC or suspicious MTC between 2004 and 2018. They identified 20 such procedures and included them in their analysis.
Read more about the diagnosis of MTC
The findings were as follows: the fine-needle aspiration biopsies had high cellularity and a pattern that was not cohesive. There were also a few loose syncytial groups. The researchers also noted some variation in the size and shape of the cells across and within cases.
The majority of cases (15 out of 20) had a predominant plasmacytoid/epithelioid cell morphology, and the remaining 5 had a spindle cell pattern. There were 8 cases of microcarcinoma (measuring 1 cm or less in diameter) and none of these showed a spindle cell morphology.
In just above half of the cases (11 out of 20), there were amyloids and 17 of them were binuclear or multinuclear. Finally, 3 cases had pseudoinclusions. In all cases, the nuclei had granular “salt and pepper” chromatin.
ICC was performed in almost all cases (18 out of 20), which showed that calcitonin, carcinoembyronic antigen, TTF1, and chromogranin were positive wherever applied. On the contrary, thyroglobulin and CK19 were negative.
“Ultrasound-guided thyroid [fine needle aspiration] – processed with LBC and ICC – is a reliable modality to detect MTC preoperatively,” the researchers concluded.
Nikas IP, Kazamias G, Vrontaki M, Rapti AS, Mastorakis E. Medullary thyroid carcinoma diagnosed with liquid-based cytology and immunocytochemistry. J Immunoassay Immunochem. Published online April 27, 2022. doi:10.1080/15321819.2022.2070025