Judd R, Bueso-Ramos C
Department of Anatomic Pathology, Grady Memorial Hospital, Atlanta, Georgia 30335.
Pediatr Pathol. 1990;10(5):829-36. doi: 10.3109/15513819009064717.
True thymic hyperplasia (enlarged gland composed of histologically unremarkable cortical and medullary parenchyma) and lymphoid hyperplasia (medullary lymphoid follicles in the clinical setting of autoimmunity) usually develop as independent pathologic processes. We reviewed the clinical features and gross and microscopic pathology of 2 hyperthyroid patients with features of both thymic hyperplasia and lymphoid hyperplasia. The diagnosis of thymic hyperplasia was supported by thymic weights greater than two standard deviations above the mean weight for age and histologic evidence of expanded cortical and medullary parenchyma. The diagnosis of lymphoid hyperplasia was supported by the increased number and size of medullary lymphoid follicles and the association with Graves' disease. This unusual combination results from two separate pathogenic mechanisms operating simultaneously in hyperthyroid patients. Elevated thyroid hormones directly stimulate the proliferation of thymic epithelium, producing thymic hyperplasia. The immune abnormalities underlying Graves' disease can also result in lymphoid hyperplasia of the thymus.
真性胸腺增生（由组织学上无异常的皮质和髓质实质构成的增大腺体）和淋巴样增生（在自身免疫临床背景下的髓质淋巴滤泡）通常作为独立的病理过程发生。我们回顾了2例具有胸腺增生和淋巴样增生特征的甲状腺功能亢进患者的临床特征、大体和显微镜下病理。胸腺增生的诊断依据是胸腺重量高于年龄平均重量两个标准差以上，以及皮质和髓质实质扩大的组织学证据。淋巴样增生的诊断依据是髓质淋巴滤泡数量和大小增加以及与格雷夫斯病的关联。这种不寻常的组合是由甲状腺功能亢进患者同时起作用的两种不同致病机制导致的。甲状腺激素升高直接刺激胸腺上皮细胞增殖，产生胸腺增生。格雷夫斯病潜在的免疫异常也可导致胸腺的淋巴样增生。
