Thompson Lester D R, Wei Christina, Rooper Lisa M, Lau Sean K
Southern California Permanente Medical Group, Department of Pathology, Woodland Hills Medical Center, 5601 De Soto Avenue, Woodland Hills, Los Angeles, CA, 91365, US.
Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD, US.
Head Neck Pathol. 2019 Dec;13(4):597-605. doi: 10.1007/s12105-019-01012-6. Epub 2019 Feb 13.
Solitary fibrous tumors of the thyroid gland are exceptionally rare. In order to further characterize the clinical and pathologic features of solitary fibrous tumor arising at this anatomic site, three cases of thyroid gland solitary fibrous tumor were analyzed in conjunction with 35 cases compiled from the English literature. Thyroid gland solitary fibrous tumors showed an equal sex distribution with a mean age at presentation of 54.4 years (range, 28-88 years). The patients typically presented with an asymptomatic, slow growing neck mass. Microscopically, the tumors were characterized by cytologically bland spindle cells with patternless growth, hypocellular and hypercellular areas, variable amounts of collagen, and ectatic, branching blood vessels. Two previous reported tumors were considered to be histologically malignant on the basis of increased mitotic activity, profound pleomorphism and tumor necrosis. Immunohistochemically, the tumor cells are variably positive with CD34, bcl-2, and CD99. STAT6 immunohistochemistry, performed on the current cases, demonstrated a strong, diffuse nuclear expression in all tumors. Among 26 patients with available follow up data (mean 47.3 months), one developed local recurrence and distant metastasis. Solitary fibrous tumors occurring in the thyroid gland are uncommon, but can be reliably diagnosed based on the presence of characteristic morphologic features as well as immunohistochemical expression of STAT6 and CD34. The majority of thyroid gland solitary fibrous tumors have exhibited an indolent clinical course, however experience is limited. The rare potential for aggressive clinical behavior requires clinical surveillance.
甲状腺孤立性纤维瘤极为罕见。为进一步明确该解剖部位发生的孤立性纤维瘤的临床和病理特征，对3例甲状腺孤立性纤维瘤病例进行了分析，并结合从英文文献中收集的35例病例。甲状腺孤立性纤维瘤的性别分布均等，就诊时的平均年龄为54.4岁（范围28 - 88岁）。患者通常表现为无症状、生长缓慢的颈部肿块。显微镜下，肿瘤的特征为细胞形态温和的梭形细胞，生长无规律，有细胞稀少和细胞丰富区域，胶原含量不等，以及扩张的分支血管。先前报道的2例肿瘤基于有丝分裂活性增加、显著的多形性和肿瘤坏死被认为在组织学上为恶性。免疫组化方面，肿瘤细胞对CD34、bcl - 2和CD99呈不同程度阳性。对当前病例进行的STAT6免疫组化显示，所有肿瘤均有强的弥漫性核表达。在26例有随访数据的患者中（平均47.3个月），1例发生局部复发和远处转移。发生于甲状腺的孤立性纤维瘤并不常见，但基于特征性形态学特征以及STAT6和CD34的免疫组化表达可作出可靠诊断。大多数甲状腺孤立性纤维瘤表现为惰性临床病程，然而经验有限。罕见的侵袭性临床行为可能性需要临床监测。
