Vascularity patterns detectable through ultrasound could aid in the detection of medullary thyroid carcinoma (MTC) among thyroid nodules with low to intermediate suspicion, according to a recently published study in Cancer Imaging.
MTC is particularly prone to lymph nodes and distant metastasis; therefore, early detection is vital. However, ultrasound sensitivity for MTC is below 75%, and fine needle aspiration has many limitations in MTC diagnosis. Although calcitonin has proven to be more sensible than fine needle aspiration, there is still controversy over the convenience of its widespread use.
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“Because of these limitations, many MTCs are still found incidentally after thyroidectomy, leading to the risk of incomplete treatment and thus of a poorer prognosis,” the authors wrote.
Although hypervascularity is recognized as an important morphologic feature of MTC, it is not included in the majority of risk stratification systems. The authors aimed to analyze the vascularity characteristics of MTC in ultrasound in order to assess its value for early diagnosis.
The retrospective analysis used data from 102 patients with a confirmed MTC diagnosis that underwent ultrasound examination. The vascular findings were compared to a control group of 62 randomly selected lesions. About 85% of nodules were classified as ultrasound-highly suspicious by American Thyroid Association and the rest as ultrasound-low suspicious.
The results reflect that about 33% of MTC cases were initially considered low risk leading to a delay in treatment. Also, it was observed that ultrasound-loss suspicious nodules tended towards central blood flow (pattern 3) lower than perinodular blood flow (pattern 4) compared to the control group.
Statistical analysis confirmed the correlation between pattern 4 and ultrasound-low suspicious MTC. Researchers also noted more penetrating branching vascularity in the ultrasound-low suspicious nodules.
The authors believe that the presence of penetrating branching vascularity represents a novel vascularity pattern that could help differentiate MTC from thyroid nodules.
“Based on societal US guidelines, some MTCs are mistakenly not categorized as high risk of malignancy, and vascularity can help diagnose l-MTC disease,” the authors concluded.
Gao L, Ma L, Li X, et al. Using preoperative ultrasound vascularity characteristics to estimate medullary thyroid cancer. Cancer Imaging. Published online June 20, 2023. https://doi.org/10.1186/s40644-023-00583-6