原发性甲状腺功能减退症伴垂体增生患者的磁共振成像表现

摘要

目的 探讨原发性甲状腺功能减退症并发垂体增生患者的临床及磁共振成像(MRI)表现.方法 回顾性分析2008年1月至2011年12月我院确诊的11例甲状腺功能减退症伴垂体增生患者鞍区MRI图像特点、临床表现及实验室检查结果.结果 11例患者主要临床表现为生长发育迟缓( 7/8),智力低下(6/8),畏寒、乏力(6/11),体重增加(6/11),月经紊乱(8/9),泌乳(3/11),儿童性早熟和阴道流血(2/2),视力障碍(3/11).实验室检查显示全部患者血清促甲状腺激素水平升高,三碘甲状腺原氨酸、甲状腺素水平降低,催乳素水平轻度升高,6例患者甲状腺抗体阳性.鞍区MRI显示11例垂体均匀对称性增大,病变位于鞍内及鞍上,5例垂体病变增大如“球状”,高度(12.22±3.12) mm;6例垂体增大向鞍上生长,呈“葫芦状”,高度(18.95±2.23)mm.全部垂体病变信号与脑灰质信号接近.垂体后叶的短T1信号均清晰可见.仅4例垂体柄在MRI上清晰可见,位于中线处无左右移位,未见明显增粗.结论 当MRI提示垂体均匀性增大时,鉴别诊断要考虑垂体增生,特别是原发性甲状腺功能减退症这一常见内分泌疾病,诊断时要密切结合患者的临床表现及实验室检查,遵循内分泌疾病定性定位诊断路径有助于正确诊断原发病,避免误诊.%Objective To explore the clinical and magnetic resonance imaging ( MRI) findings of pituitary hyperplasia due to primary hypothyroidism. Method The clinical presentations, laboratory examinations , and MRI findings of 11 patients with pituitary hyperplasia secondary to primary hypothyroidism diagnosed at our hospitals from the beginning of 2008 to the end of 2011 were retrospectively reviewed. Results The clinical manifestationa in 11 patients included growth arrest ( 7/8 ) , mental retardation ( 6/8 ) , cold intolerance and fatigue (6/11) , slightly increased body weight (6/11) , galactorrhea (3/11) , paramenia (8/9) , precocious puberty companying vaginal bleeding (2/2) , and blurry vision (3/11). Laboratory investigations revealed grossly increased thyroid stimulating hormone, decreased thyroxine, and slightly elevated prolactin levels in all cases. Thyroid antibody was positive in six cases. On MRI, pituitary mass were detected a large intra-sellar with/without suprasellar extension in all patients, showing the characteristic of symmetric enlargement.Spherical shape was viewed in 5 cases, with the height of (12. 22 ±3. 12) mm. In the other 6 cases, the pituitary mass with the shape of calabash extended superiorly to suprasellar area, with a height of ( 18. 95 ± 2. 23) mm. The signal of pituitary mass was isointense to grey matter both on Tl weighted imaging and T2 weighted imaging. Bright short Tl signal in posterior lobe of pituitary was visible. Pituitary stalk was detected only in 4 cases from MRI without dislocation, while the width of pituitary stalk was within the normal limit. Conclusions Pituitary hyperplasia should be considered when homogenous enlargement of the pituitary gland is found on MRI. The integration of MRI findings, clinical manifestations, and laboratory findings is helpful for the proper identification of the primary endocrine disease and thus avoid misdiagnosis.