甲状旁腺癌临床病理学特点分析

Clinicopathologic features of parathyroid carcinoma：a study of 11 cases with review of literature

目的探讨甲状旁腺癌（ PTC）的临床表现及病理形态学特征。方法对1994年12月至2012年10月间收集的11例PTC及40例甲状旁腺腺瘤（ PA）的临床表现、实验室检查结果及病理组织形态学、免疫组织化学特点进行分析，复习相关文献，讨论PTC及PA的诊断要点及鉴别诊断。结果 PTC组的主要临床表现为颈部肿块（11/11）、高钙血症（11/11）、甲状旁腺功能亢进（11/11），部分患者伴有骨质疏松症（10/11）；PA组的主要临床表现是高钙血症（40/40）、甲状旁腺功能亢进（40/40）。 PTC显微镜下特点为肿瘤细胞胞质透亮或者嗜酸性，呈巢团状排列，瘤细胞异型性不明显，但细胞核分裂象不少见[核分裂象计数（1～3）/10 HPF]，局部可见坏死，肿瘤瘤体表面纤维膜增厚，中央可见粗大的纤维组织分隔，所有病例均可见瘤细胞侵犯被膜和血管，其中2例局部区域可见肿瘤突破被膜累及周围组织；PA显微镜下特点为肿瘤细胞胞质呈嗜酸性或者透亮，细胞排列成小梁状、腺样及实性，腺腔内可见红染分泌物，大部分肿瘤（35/40）包膜完整，所有肿瘤均未见坏死，核分裂象罕见（核分裂象计数＜1/10 HPF）。免疫组织化学：PTC肿瘤细胞CK19、嗜铬粒素A（CgA）、突触素、甲状旁腺激素（ PTH）阳性情况分别为11/11、9/11、7/11、11/11，甲状腺球蛋白（ TG）、甲状腺转录因子-1（TTF-1）及降钙素阴性，Ki-67阳性指数均＜10％（2％～9％）；PA肿瘤细胞CK19、PTH、CgA及突触素均为阳性，TTF-1、TG、降钙素均为阴性，Ki-67阳性指数＜3％。随访PTC患者11～224个月，2例死亡，其余7例均未见复发及转移，2例失访。 PA患者随访时间10～48个月，均未见复发。结论PTC是一种比较少见的恶性内分泌肿瘤，主要表现为甲状旁腺功能亢进和颈部包块，病理学形态上，肿瘤呈巢团状排列，可见坏死，被膜和血管侵犯是确诊依据，该肿瘤需要与PA、甲状腺乳头状癌、甲状腺髓样癌等肿瘤鉴别。

Objective To study the clinicopathologic characteristics of parathyroid carcinoma （ PTC）.Methods Eleven cases of PTC encountered during the period from 1994 to 2012 were enrolled into the study.Forty cases of parathyroid adenoma （ PA ） were also retrieved for comparison.The clinical manifestations , laboratory results and pathologic features were analyzed , with literature review.Results The main clinical manifestations of PTC included neck mass （ 11/11 ） , hypercalcemia （ 11/11 ） and hyperparathyroidism （ 11/11 ）.Most patients also had osteoporosis （ 10/11 ）.In contrast , PA often manifested as hypercalcemia （ 40/40 ） and hyperparathyroidism （ 40/40 ）.Histologic examination of PTC showed that the tumor cells contained clear to eosinophilic cytoplasm and separated by dense bands of fibrosis.The tumor mass was surrounded by thick fibrous capsule.Foci of capsular invasion and vascular permeation were identified at the tumor periphery in all cases.Cellular atypia was not conspicuous but mitotic figures and coagulative necrosis were easily identified.On the other hand , PA were composed of tumor cells with clear to eosinophilic cytoplasm , forming glands, trabeculae or nests.Most of them （35/40） had intact fibrous capsule.Mitotic figures were rarely encountered and tumor necrosis was absent.Immunohistochemical study showed that the tumor cells in PTC were positive for CK 19 （ 11/11 ） , chromogranin A （9/11）, synaptophysin （7/11） and parathyroid hormone （11/11）.They were negative for thyroglobulin , TTF-1 and calcitonin.The Ki-67 index was less than 10% （ range =2% to 9%）.In contrast, the tumor cells in PA were positive （40/40） for CK19, chromogranin A, synaptophysin and＆amp;nbsp;parathyroid hormone.They were negative for thyroglobulin , TTF-1 and calcitonin.The Ki-67 index was less than 3%.Follow up-data were available in 9 cases of PTC （ duration of follow up =11 months to 224 months） and 7 of the patients were still alive.Follow up of all PA cases showed no evidence of recurrence.Conclusions PTC is a rare malignant endocrine tumor presenting as neck mass.Histologic features suggestive of malignant behavior include presence of coagulative tumor necrosis and capsular /vascular invasion.It needs to be distinguished from other entities such as parathyroid adenoma , papillary thyroid carcinoma and medullary thyroid carcinoma.