摘要：

目的 报告1 例原发性甲状腺功能减退症继发垂体增生伴高泌乳素血症患者，探讨其组织形态学、免疫组织化学表型、诊断与鉴别诊断、治疗及预后等临床病理学特点。方法与结果 女性患者，29 岁，临床表现为月经失调1 年，溢乳3 个月，头痛1 周。MRI 提示垂体瘤可能性大。遂行经鼻蝶鞍区占位性病变探查术。组织学形态观察，部分腺泡细胞明显增生，呈局灶性结节状。免疫组织化学染色，增生的腺泡细胞弥漫性表达突触素、促甲状腺激素，部分表达催乳素，不表达甲状腺转录因子-1，淋巴细胞散在表达白细胞共同抗原，Ki-67 抗原标记指数约< 1%。病理诊断为垂体增生，最终临床诊断为甲状腺功能减退症。持续服用左甲状腺素钠（优甲乐）100 μg/d，随访13 个月，一般状况良好。结论 垂体增生诊断困难，明确诊断须依靠临床病史、组织学形态特征和免疫组织化学表型，应注意与垂体腺瘤尤其是垂体微腺瘤相鉴别。

关键词: 甲状腺功能减退症, 垂体, 增生, 高催乳素血症, 免疫组织化学, 病理学

Abstract:

Objective To discuss the histological characteristics, immunohistochemical phenotypes, diagnosis and differential diagnosis, treatment and prognosis of one case of primary hypothyroidism presenting as pituitary hyperplasia concurrent with hyperprolactinemia.  Methods and Results  A 29-year-old female presented menoxenia for one year, galactorrhea for 3 months, and headache for one week. Head MRI demonstrated a sellar space-occcupying lesion and a pituitary adenoma was suspected. Therefore, the patient underwent an exploratory surgery via transnasal-sphenoidal approach under general anesthesia. During the surgery the lesion was located in the right side of sella turcica. It was hard, tough and gray with poor blood supply. Under optical microscopy, the acinar cells showed a diffuse hyperplasia, with focal nodular expansion. The boundary between hyperplastic and normal acinus was ill-defined. By using immunohistochemical staining, the hyperplastic cells were diffusely positive for synaptophysin (Syn) and thyroid stimulating hormone (TSH), partially positive for prolactin (PRL), and negative for thyoid
transcription factor-1 (TTF-1). Lymphocytes were scatteredly positive for leukocyte common antigen (LCA). Ki-67 labeling index was less than 1%. Pathological diagnosis was pituitary hyperplasia. The final clinical diagnosis was hypothyroidism. The patient took levothyroxine sodium (Euthyrox) 100 μg/d continously, and
was well during the 13-month follow-up.  Conclusions  Preopertive diagnosis of pituitary hyperplasia is difficult．Definite diagnosis could be made by clinical history, typical histopathological characteristics and immunohistochemical phenotypes. Differential diagnosis from pituitary adenoma, especially microadenoma,
should be paid attention.

Key words: Hypothyroidism, Pituitary gland, Hyperplasia, Hyperprolactinemia, Immunohistochemistry, Pathology