去分化实体型甲状腺乳头状癌伴黏膜相关淋巴组织结外边缘区淋巴瘤1例病理特征并文献分析

Dedifferentiated solid variant papillary thyroid carcinoma with extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue:a case report with pathological characteristics and literature analysis

目的:分析1例罕见的去分化实体型甲状腺乳头状癌(solid variant papillary thyroid carcinoma, SVPTC)伴黏膜相关淋巴组织结外边缘区淋巴瘤(extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue,MALT)患者的临床表现、超声及相关影像学特征,并对其病理特征进行探讨。方法:分析本例患者的临床资料、影像学特征及病理诊断特点,针对其SVPTC、去分化表现、MALT各相关特征进行分别论述。结果:甲状腺组织大体灰白质硬,光镜下可见肿瘤细胞排列呈实性、巢状,核分裂相易见;未见乳头状癌典型的细胞核特征;间质由形态各异的小淋巴细胞组成,可见较多Russell小体。免疫组织化学(immunohistochemistry, IHC)检测显示,CK19(+),Ki-67(80%+),TG(-),TTF-1(+),Bcl-6(+),CK5/6(-),CD117(-);周围淋巴细胞CD20(+)、CD79α(+)、CD3(+)、CD5(+)、CD43(+)、Bcl-2(+)。分子病理学检查结果示,BRAF基因未检测到突变,TERT启动子有突变。B淋巴瘤克隆基因重排结果为阳性。最终该患者经病理诊断为去分化SVPTC伴MALT。结论:去分化SVPTC伴MALT极其罕见,患者预后差,各病理特征都具有一定的临床价值,需仔细分析研究。

Objective: To report the clinical manifestation, ultrasonographic imaging(US) feature and pathological feature of a rare case of dedifferentiated solid variant papillary thyroid carcinoma(SVPTC) with extranodal marginal zone lym-phoma of mucosa-associated lymphoid tissue(MALT) and to discuss its pathological characteristics. Method: The clinical data, imaging feature and pathologic feature of this rare case were analyzed, and the characteristics of SVPTC, dedifferentiation and MALT were discussed separately.Result: The thyroid tissue was grossly grayish-white in color, and the microscopic examination showed that the tumor cells were arranged in a solid, nested shape, and the mitotic figures were easy to see;no typical nuclear features of papillary carcinoma were seen;the interstitial was composed of small lymphocytes with different forms.Some Russell bodies could be seen. IHC showed CK19(+), Ki67(80%+), TG(-), TTF-1(+), Bcl-6(+),CK5/6(-),CD117(-);peripheral lymphocytes: CD20(+), CD79α(+), CD3(+), CD5(+), CD43(+), Bcl-2(+). Molecular pathology showed that no mutations were detected in BRAF but mutations in TERT promoter were detected.B lymphoma clone gene rearrangement was positive.The final pathological diagnosis was dedifferentiated SVPTC with MALT. Conclusions: Dedifferentiated SVPTC with MALT is extremely rare and has poor prognosis. Each feature deserves careful documentation and discussion.