Chronic granulomatous lesions after thyroidectomy: imaging findings.

OBJECTIVE The purpose of this report is to describe the imaging appearance of granulomatous inflammation in the neck presenting as a late complication in patients who have undergone thyroidectomy for differentiated thyroid carcinoma. CONCLUSION Granulomatous inflammation can occur as a palpable mass in the operative bed of asymptomatic patients who have undergone thyroidectomy for thyroid carcinoma. The diagnosis may be suggested when the lesion shows the sonographic appearance of a poorly defined hypoechoic lesion or lesions with a central echogenic nonshadowing focus, often within the sternocleidomastoid muscle. These lesions may appear as complex cystic masses on CT and MRI and may have increased activity on PET. Percutaneous biopsy can establish the diagnosis of an inflammatory lesion and can exclude underlying active infection and malignancy.