背景:透明质化小梁肿瘤是一种罕见的滤泡细胞源性甲状腺肿瘤,被认为是具有恶性潜能的交界性肿瘤,而不是良性肿瘤。RET/PTC重排和核细胞学特征的检测表明透明小梁肿瘤与甲状腺乳头状癌之间存在关系。最近对透明小梁肿瘤的致病基因改变的一些观察表明,透明小梁肿瘤与甲状腺乳头状癌无关。应该被视为一个独立的实体。在这里,我们介绍了一例具有透明化小梁肿瘤样特征的甲状腺乳头状癌,并从组织病理学角度讨论了其有趣的方面和诊断问题。
方法:一名19岁的日本女性甲状腺肿大患者入院。根据细针穿刺细胞学检查,增大的结节被怀疑是滤泡性病变或滤泡性肿瘤。在甲状腺左叶中检测到直径约3cm的结节性病变。组织学分析显示肿瘤细胞主要排列在卵泡中。偶尔有小梁排列和乳头状结构的实巢混合在一起,肿瘤细胞显示磨玻璃核和偶尔的核槽。在肿瘤实体部分的间质中观察到类花瓣和块状高碘酸希夫和高碘酸-次甲基胺阳性基底膜成分。在实体区域内的细胞中还观察到MIB-1的不完全膜免疫反应性(Ki-67(细胞增殖标记))。此外,该肿瘤表现为包膜外浸润并转移到甲状腺周围淋巴结,提示可能是恶性肿瘤.然而,BRAFV600E突变,RET/PTC重排,未检测到PAX8/GLIS1和PAX8/GLIS3重排。
结论:我们诊断为甲状腺乳头状癌,具有透明化小梁肿瘤的特征。重要的是,这种情况可能表明甲状腺乳头状癌和透明化小梁肿瘤之间可能存在关系,尽管无法检测到特定的遗传改变。我们还讨论了细针抽吸细胞学的术前诊断困难以及这种情况下的异常病理发现。
BACKGROUND: Hyalinizing trabecular tumor is a rare follicular cell-derived thyroid neoplasm that is considered to be a borderline tumor with malignant potential rather than a benign tumor. The detection of RET/PTC rearrangements and nuclear cytologic features suggests a relationship between hyalinizing trabecular tumor and papillary thyroid carcinoma. Some recent observations of pathogenic genetic alterations in hyalinizing trabecular tumor have indicated that hyalinizing trabecular tumor is not related to papillary thyroid carcinoma, and should be considered an independent entity. Here we present a
case of papillary thyroid carcinoma with hyalinizing trabecular tumor-like features and discuss its interesting aspects and diagnostic issues from a histopathological perspective.
METHODS: A 19-year-old Japanese woman with an enlarged thyroid gland was admitted to our hospital. Based on fine-needle aspiration cytology, the enlarged nodule was suspected to be a follicular lesion or follicular tumor. A nodular lesion approximately 3 cm in diameter was detected in the left lobe of the thyroid gland. Histological analysis revealed that the tumor cells were mainly arranged in follicles. Solid nests with occasional trabecular arrangements and papillary structures were intermingled, and the tumor cells showed ground-glass nuclei and occasional nuclear grooving. Petaloid and block-like periodic-acid-Schiff and periodic-acid-methenamine-positive basement membrane components were observed in the interstitium of the solid portions of the tumor. Incomplete membranous immunoreactivity of MIB-1 (Ki-67 (cell prolferation marker)) was also observed in the cells within the solid areas. Moreover, this tumor displayed extracapsular invasion and metastasis to the perithyroidal lymph nodes, suggesting that it may be a malignant tumor. However, BRAFV600E mutation, RET/PTC rearrangements, and PAX8/GLIS 1 and PAX8/GLIS 3 rearrangements were not detected.
CONCLUSIONS: We diagnosed the tumor as a papillary thyroid carcinoma with characteristic features of hyalinizing trabecular tumor. Importantly, this
case may indicate a possible relationship between papillary thyroid carcinoma and hyalinizing trabecular tumor, although specific genetic alterations could not be detected. We also discuss the preoperative diagnostic difficulties with fine-needle aspiration cytology and the unusual pathological findings in this
case.