甲状腺玻璃样变性小梁状肿瘤10例临床病理分析

Hyalinizing trabecular tumor of the thyroid:a clinicopathological study of ten cases

目的探讨甲状腺玻璃样变小梁状肿瘤(HTT)临床病理特点、诊断与鉴别诊断。方法对10例HTT的临床资料、组织学形态及免疫组化特征进行分析,复习相关文献,讨论HTT的诊断要点与鉴别诊断,并分析预后。结果 10例HTT中,女性7例,男性3例,最小年龄27岁,最大年龄61岁,平均49.9岁。肿瘤位于左侧腺叶8例,位于右侧腺叶2例。10例中,手术切除标本8例,粗针穿刺标本2例。手术切除标本中,肿瘤最大径6 cm,最小径0.2 cm。组织学形态示肿瘤具有特征性小梁状生长方式和小梁内玻璃样变物质。瘤细胞呈多角形、卵圆形或高柱状,具有嗜酸或透明的胞质。细胞核呈卵圆形,具有不明显的核仁,可见核内包涵体和核沟,核分裂象罕见。瘤细胞常可见胞质内黄色小体。免疫组化:肿瘤细胞TTF-1(10/10)、TG(10/10)和CD56(10/10)(+),Ki-67(MIB-1)肿瘤细胞显示胞膜呈阳性着色(10/10),Ki-67(SP6)核阳性细胞数<1%(10/10),部分病例galectin-3(3/10)和CK19(2/10)(+),Syn、Cg A和calcitonin均呈(-)。10例患者分别经过1~11年随访均无复发或转移。结论 HTT是一种罕见的甲状腺肿瘤。临床表现无特异性,易误诊。确诊HTT需要结合组织病理学特征及Ki-67(MIB-1)的表达模式。HTT具有低度恶性潜能,需要进行长时间随诊和观察。

Objective To investigate the clinicopatholocical characteristics and diagnosis and differential diagnosis of hyalinizing trabecular tumors（ HTT） of the thyroid. Methods The clinical manifestations, morphological and immunohistochemical features were analyzed in ten cases of HTT of our department. The associated literatures were discussed with the key points of the diagnosis and the differential diagnosis. Results There were 7 females and 3 males patients aged from 27 to 61 years（ mean 49. 9 yeas）. Eight tumors located in the left lobe of the thyroid and 2 tumors in the right lobe. There were 8 specimen from thyroidectomy and 2 cases from core needle biopsy. Grossly,diameter of the tumors ranged from 6 cm to 0. 2 cm. Microscopically,the tumor typically consisted of a trabecular growth pattern and hyalinizing material deposited intratrabecular widespreadlly. The cytological features mimicked papillary thyroid carcinoma（ PTC）.The tumor cells were polygonal,oval,or high columnar with an acidophilic or clear cytoplasm. The nuclei were oval with inconspicuous small nucleoli,prominent grooves and pseudoinclusions. Mitosis was rare. Cytoplasmic yellow bodies were frequently found. Immunohistochemically,tumor cells were positive for TTF-1（ 10/10）,TG（ 10/10）,CD56（ 10/10）,and negativity for Syn,Calcitonin and Cg A. Galectin-3 was expressed weakly in 3 cases（ 3/10）,and 2 of 10 cases expressed CK19. Staining with the Ki-67（ MIB-1） antibody showed membranous and cytoplasm immunoreactivity of all cases（ 10/10）,whereas an other clone of Ki-67（ SP6） showed a common nuclear pattern,with an index less than 1%.After a follow-up for 12 months to 11 years,the patients were alive without local recurrence or metastasis. Conclusions HTT is a rare thyroid tumor with no specific clinical features. But it is often misdiagnosed. The correct diagnosis of HTT mainly depends on typical histopathological features and characteristic expression pattern of MIB-1 immunohistochemical staining. HTTs are neoplams with very low malignant potential,which need long term follow-up.