Objective:

To investigate the value of high frequency ultrasonography in the diagnosis of medullary thyroid carcinoma(MTC).

Methods:

The ultrasound performances of 25 nodules of pathologically confirmed MTC in 21 patients were retrospectively analyzed. The nodular location

size

boundary

shape

echo level

internal calcification type and cervical lymph node metastasis were observed. The results were compared with surgical findings and pathology results.

Results:

There were 10 cases (47.6%) complicated with other nodules. There were 16 nodules (64.0%) with clear boundaries

1

9 nodules (76.0%) with aspect ratio less than or equal to 1

16 nodules (64.0%) with irregular shapes

17 nodules (68.0%) with diameters greater than 1 cm

17 nodules (68.0%) with weak echoes. Calcification appeared in 19 nodules (76.0%)

in which 11 nodules (57.9%) with coarse calcifications and 8 nodules (42.1%) with small calcifications. There were 7 cases (33.3%) with cervical lymph node metastasis. Seven cases (33.3%)were misdiagnosed as Thyroid Imaging Reporting and Data System (TI-RADS) III nodular goiter by ultrasonography.

Conclusion:

Compared to papillary carcinoma

MTC has special performances such as clear boundary

aspect ratio less than or equal to 1

weak echo and coarse calcification. It is often misdiagnosed as nodular goiter.