Nishihara Eijun, Hirokawa Mitsuyoshi, Ohye Hidemi, Ito Mitsuru, Kubota Sumihisa, Fukata Shuji, Amino Nobuyuki, Miyauchi Akira
Kuma Hospital, Center for Excellence in Thyroid Care, Kobe, Japan.
Thyroid. 2008 Nov;18(11):1221-5. doi: 10.1089/thy.2008.0096.
Subacute thyroiditis (SAT) has been rarely reported to coexist with thyroid carcinomas. The objective of the study was to assess sequential ultrasonographic and histopathological findings of SAT in the context of complicating thyroid carcinomas.
Of 1152 patients with SAT who visited our thyroid clinic at Kuma Hospital from 1996 through 2006, 5 cases complicated by papillary carcinoma underwent surgical resection 3-16 months after SAT onset. Ultrasonographic examinations and thyroid function tests were performed in all patients at onset of SAT and just before surgery. Sequential histopathological features of regenerated thyroid and carcinoma involvement were evaluated.
Heterogenous areas with microcalcifications in the thyroid or lymphadenopathy in three patients were clues for the nodular involvement with papillary carcinoma on the initial ultrasonographic examination. In contrast, diffuse hypoechoic change in the thyroid in two patients made it impossible to differentiate nodular involvement from inflammatory lesion. Histopathological examination of surgical specimens showed granulomatous and fibrotic changes. These were present about 3 months from SAT onset, and residual fibrosis remained several additional months, in the condition of no inflammatory hypoechoic lesions. In the areas of papillary carcinoma overlapping with transient inflammatory involvement, some lymphocytes and fibrotic changes were present in the stroma of papillary foci, but no granulomatous formation was present in any sections. Continuity with fibrosis around regenerated follicular cells was absent. The degree of lymphoid infiltrate and fibrotic change in the papillary carcinoma was not dependent on periods between SAT onset and the resection.
SAT may produce ultrasound changes that obscure the coexistence of papillary carcinoma, but affects no lymphoid infiltrate and fibrotic changes involved in carcinoma throughout the clinical course. We recommend that patients with SAT have ultrasonography after they recover. Further workup, including cytological examination of hypoechoic regions, should be performed if they are present as measuring 1 cm or larger.
亚急性甲状腺炎（SAT）合并甲状腺癌的情况鲜有报道。本研究的目的是评估在合并甲状腺癌的情况下SAT的系列超声检查及组织病理学表现。
1996年至2006年间，1152例在熊本医院甲状腺门诊就诊的SAT患者中，5例合并乳头状癌的患者在SAT发病后3至16个月接受了手术切除。所有患者在SAT发病时及手术前均进行了超声检查和甲状腺功能测试。对再生甲状腺的系列组织病理学特征及癌累及情况进行了评估。
3例患者甲状腺内有微钙化的异质区域或淋巴结病变，这是初次超声检查时提示乳头状癌结节累及的线索。相比之下，2例患者甲状腺弥漫性低回声改变使得无法区分结节累及与炎性病变。手术标本的组织病理学检查显示有肉芽肿性和纤维化改变。这些改变在SAT发病后约3个月出现，在无炎性低回声病变的情况下残留纤维化又持续了几个月时间。在与短暂炎性累及重叠的乳头状癌区域，乳头状病灶的间质中有一些淋巴细胞和纤维化改变，但任何切片中均无肉芽肿形成。再生滤泡细胞周围不存在与纤维化的连续性。乳头状癌中淋巴细胞浸润和纤维化改变的程度不取决于SAT发病与切除之间的时间间隔。
SAT可能产生使乳头状癌共存情况模糊不清的超声改变，但在整个临床过程中不影响癌所涉及的淋巴细胞浸润和纤维化改变。我们建议SAT患者康复后进行超声检查。如果存在直径1厘米或更大的低回声区域，应进行进一步检查，包括对这些区域进行细胞学检查。
