甲状腺透明变梁状肿瘤临床病理观察

Clinicopathologic features of hyalinizing trabecular tumor of the thyroid gland

目的探讨甲状腺透明变梁状肿瘤的临床病理特征。方法分析2例甲状腺透明变梁状肿瘤的形态学特征、免疫组化及分子遗传学表现,并复习相关文献。结果2例均为女性,年龄分别为69岁和49岁,因偶然发现甲状腺单发结节就诊。组织学上,肿瘤呈实性小梁状或巢状生长,小梁间可见显著的透明变性。瘤细胞呈多边形或梭形,核卵圆形或长形,可见核沟及核内假包涵体,并见小核仁,核分裂象罕见。免疫组化:2例均弥漫表达Tg、TTF-1、PAX8、CK18,不同程度地表达Galectin-3、CK7,而CK19、MC、Calcitonin、Syn、CgA、S-100均为阴性,透明变间质呈PAS染色阳性,Ki-67<2%。分子遗传学:2例均无BRAF V600E、N-RAS及RET基因突变。2例随访66个月和10个月,均未复发及转移。结论甲状腺透明变梁状肿瘤是一种罕见的甲状腺滤泡上皮源性肿瘤,有独特的临床病理学特征。

Objective To investigate the clinicopathological features of hyalinizing trabecular tumor of the thyroid gland.Methods The morphological features,immunohistochemical and molecular genetic characteristics were analyzed in 2 cases of hyalinizing trabecular tumor,the relevant literatures were reviewed.Results The two patients were 69-and 49-year-old female,respectively and were all diagnosed as single thyroid nodule by chance.Histologically,the tumors showed solid trabecular or nest-like growth with clear degeneration between trabecula.The tumor cells were polygonal or fusiform with oval or elongated nuclei.Nuclear sulcus,pseudoinclusion bodies and small nucleolus could be seen in some nuclei.Immunohistochemistry showed that Tg,TTF-1,PAX8 and CK18 were diffusely expressed in the tumor cells while Galectin-3 and CK7 were expressed in different degrees.CK19,MC,Calcitonin,Syn,CgA and S-100 were all negative.The hyaline stroma was positive for PAS.Ki-67 was lower than 2%.The mutation of BRAF V600 E,N-RAS and RET genes were not detected in the 2 cases.No recurrence or metastasis was found during the follow-up of 66 and 10 months respectively.Conclusion Hyalinizing trabecular tumor of the thyroid gland is a rare thyroid follicular epithelial tumor with unique clinical pathological features.It needs to be differentiated from papillary thyroid carcinoma,medullary thyroid carcinoma and thyroid paraganglioma.