Abstract
Purpose
This study aimed to clarify the sonographic features of suture granuloma and recurrent
carcinoma newly detected after thyroidectomy.
Materials and Methods
We retrospectively analyzed ultrasound reports with images of 25 cases of suture granuloma
and 18 cases of recurrent carcinoma that newly appeared in the resected area after
thyroidectomy in our institution.
Results
Both suture granulomas and recurrent carcinomas more frequently exhibited multiple
lesions rather than solitary lesions. Suture granulomas tended to appear in the more
superficial areas than the carotid artery, while recurrent carcinomas were more common
between the trachea and carotid artery. A total of 10 of the 11 suture granulomas
that we followed up decreased in size. Recurrent carcinomas showed irregular shape
(55.6%), taller-than-wide shape (38.9%), low internal echogenicity (83.3%), and no
punctate microcalcifications. By contrast, suture granulomas were fusiform in shape
(56.0%) and showed linear internal echo parallel to the tissue plane on the longitudinal
scan (64.0%). The vascular flow sign was mild to none in the majority of both lesions.
Conclusion
Fusiform shape and linear internal echoes indicate suture granuloma, while irregular
shape, taller-than-wide shape, and low echogenicity indicate recurrent carcinoma.
Given that the clinical management of suture granuloma differs from that of recurrent
carcinoma, it is important to distinguish between these two lesions.
Key words
Thyroid - Suture granuloma - Recurrent carcinoma - Ultrasound - Thyroidectomy