Department of Pathology, MD Anderson Cancer Center, Houston, TX 77030, USA.
Hum Pathol. 2013 Aug;44(8):1612-6. doi: 10.1016/j.humpath.2013.01.010. Epub 2013 Mar 22.
Twelve cases of thymomas with prominent glandular differentiation are presented. The patients were 7 men and 5 women aged between 45 and 68 years (average, 56.5 years). Clinically, the patients presented with nonspecific symptoms of chest pain, cough, and fatigue. None of the patients had a history of myasthenia gravis or other autoimmune syndrome. Thymectomy was performed in all patients. The tumor size ranged from 4 to 7 cm in greatest diameter. Macroscopically, the tumors were described as firm and light tan without areas of necrosis, hemorrhage, or cystic change. Histologically, 7 tumors were classified as spindle cell (World Health Organization type A), 2 as mixed spindle cell and conventional (A+B1), 2 as conventional (B1), and 1 as atypical thymoma (B3). In 4 cases, the tumors showed invasion into periadipose thymic tissue. All cases showed the typical growth patterns of their particular subtypes. In addition, a distinct glandular component was present in all cases showing mucinous differentiation in 4 of them. Immunohistochemical studies showed tumor cells positive for CAM5.2, cytokeratin 5/6, and Pax8 and negative for carcinoembryonic antigen, thyroid transcription factor 1, and epithelial membrane antigen. Calretinin showed focal weak staining in the nonmucinous glandular components in 3 cases. Follow-up information obtained in 8 patients showed that all were alive and well in a period ranging from 2 to 5 years. The possibility of a glandular component in thymomas should be kept in mind in the assessment of mediastinoscopic biopsies to avoid misdiagnosis for other neoplasms that may require different treatment modalities.
本文报道了 12 例具有明显腺分化的胸腺瘤。患者为 7 名男性和 5 名女性，年龄 45 至 68 岁（平均 56.5 岁）。临床上，患者表现为胸痛、咳嗽和疲劳等非特异性症状。无肌无力或其他自身免疫综合征病史。所有患者均行胸腺切除术。肿瘤大小最大直径为 4 至 7 厘米。大体上，肿瘤质地坚硬，呈浅棕色，无坏死、出血或囊性变。组织学上，7 例肿瘤分为梭形细胞型（世界卫生组织 A 型），2 例混合梭形细胞和常规型（A+B1 型），2 例常规型（B1 型），1 例非典型胸腺瘤（B3 型）。4 例肿瘤侵犯脂肪胸腺组织。所有病例均表现出其特定亚型的典型生长模式。此外，所有病例均存在明显的腺成分，其中 4 例显示黏液分化。免疫组织化学研究显示肿瘤细胞阳性表达 CAM5.2、细胞角蛋白 5/6 和 Pax8，阴性表达癌胚抗原、甲状腺转录因子 1 和上皮膜抗原。3 例非黏液性腺成分中钙视网膜蛋白呈局灶性弱阳性染色。在 8 例患者中获得的随访信息显示，所有患者在 2 至 5 年的随访期内均存活且状况良好。在评估纵隔镜活检时，应注意胸腺瘤中腺成分的可能性，以避免误诊为可能需要不同治疗方式的其他肿瘤。
