Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD, USA.
Am J Surg Pathol. 2011 May;35(5):757-61. doi: 10.1097/PAS.0b013e3182147fa8.
Clear-cell renal cell carcinoma (ccRCC) may present with metastatic lesions in patients with a concurrent undiagnosed primary or a remote history of ccRCC. The thyroid is not uncommonly involved by metastatic ccRCC, in which a metastasis could be misinterpreted as a clear-cell change in adenomatoid nodules, follicular adenomas, or parathyroid glands. PAX8 is a transcription factor expressed by thyroid and renal-lineage cells. No previous study has evaluated the diagnostic use of PAX8 and ccRCC marker carbonic anhydrase IX (CAIX) in this setting. Cases of metastatic ccRCC in the thyroid (n=12), parathyroid glands and adenomas with clear-cell change (n=6), papillary thyroid carcinoma (n=6), thyroid follicular adenomas (n=5), and adenomatoid nodules with clear-cell change (n=5) were studied. Cases were assessed by standard immunohistochemistry for thyroid transcription factor-1 (TTF-1), thyroglobulin (TGB), PAX8, and CAIX. The extent and intensity of nuclear or cytoplasmic immunoexpression were assessed, with any labeling considered as a positive result. All metastatic ccRCCs were positive for PAX8 (moderate-to-strong, patchy-to-diffuse) and CAIX (strong, diffuse), and were negative for TTF-1 and TGB. All primary thyroid lesions labeled strongly and diffusely for TTF-1, TGB, and PAX8, and were negative for CAIX. Parathyroid tissues were negative for TTF-1, TGB, PAX8, and CAIX. An immunoprofile of "TTF1(-)/TGB(-)/CAIX(+)" was 100% sensitive and specific for metastatic ccRCC of the thyroid. The reverse profile "TTF1(+)/TGB(+)/CAIX(-)" supported a primary thyroid lesion. PAX8 was not useful in distinguishing metastatic ccRCC from thyroid lesions.
透明细胞肾细胞癌（ccRCC）可在同时患有未诊断的原发性或远处 ccRCC 病史的患者中出现转移病灶。甲状腺通常也会被转移性 ccRCC 累及，其中转移可能被误诊为腺瘤样结节、滤泡性腺瘤或甲状旁腺的透明细胞变化。PAX8 是一种转录因子，在甲状腺和肾系细胞中表达。以前的研究尚未评估在这种情况下 PAX8 和 ccRCC 标志物碳酸酐酶 IX（CAIX）在诊断中的应用。研究了甲状腺（n=12）、甲状旁腺和透明细胞改变的腺瘤（n=6）、甲状腺乳头状癌（n=6）、甲状腺滤泡性腺瘤（n=5）和透明细胞改变的腺瘤样结节（n=5）中转移性 ccRCC 的病例。通过标准免疫组织化学评估甲状腺转录因子-1（TTF-1）、甲状腺球蛋白（TGB）、PAX8 和 CAIX。评估核或细胞质免疫表达的程度和强度，任何标记均被认为是阳性结果。所有转移性 ccRCC 均对 PAX8（中度至强，斑片状至弥漫性）和 CAIX（强，弥漫性）呈阳性，对 TTF-1 和 TGB 呈阴性。所有原发性甲状腺病变均对 TTF-1、TGB 和 PAX8 强烈和弥漫性表达，对 CAIX 呈阴性。甲状旁腺组织对 TTF-1、TGB、PAX8 和 CAIX 均呈阴性。“TTF1(-)/TGB(-)/CAIX(+)”的免疫组化谱对甲状腺转移性 ccRCC 的敏感性和特异性均为 100%。相反的“TTF1(+)/TGB(+)/CAIX(-)”支持原发性甲状腺病变。PAX8 在区分转移性 ccRCC 与甲状腺病变方面没有帮助。
