Kochi Medical School, Kochi University, Kohasu, Oko-cho, Nankoku, Japan.
Pituitary. 2010;13(1):78-9. doi: 10.1007/s11102-009-0208-9.
A 55-year-old woman with signs of acromegaly was referred to our hospital. Endocrinological examinations showed that she had high levels of growth hormone (GH; 5.54 ng ml(-1); normal range: 0.66-3.68 ng ml(-1)) and insulin-like growth factor-I (IGF-I; 508 ng ml(-1); normal range: 37-266 ng ml(-1)) levels, incomplete suppression of serum GH following a 75-gram oral glucose tolerance test (oGTT; trough GH 3.66 ng ml(-1)), and paradoxical GH responses to a TRH provocation test (peak GH 38.9 ng ml(-1)). Dynamic magnetic resonance imaging (MRI) suggested the presence of an intrasellar mass lesion (5.9 x 2.8 mm) in the left part of her pituitary gland (Fig. 1a, upper panel). F-18 fluorodeoxyglucose (FDG) positron emission tomographic (PET) imaging clearly showed focal but remarkable FDG uptake (Fig. 1a, lower panel), consistent with the localization of the tumor suspected on MRI. The tumor was removed by transsphenoidal surgery. Subsequent histological analysis confirmed the diagnosis of a GH-producing pituitary adenoma. After removal, serum IGF-I levels decreased to a normal range (178 ng ml(-1)), and serum GH was appropriately suppressed during oGTT (trough GH 0.30 ng ml(-1)), suggesting that complete resection was obtained [1]. While postsurgical changes made it difficult to detect any residual lesion on MRI (Fig. 1b, upper panel), abnormal FDG uptake was not seen on FDG-PET after surgery (Fig. 1b, lower panel). PET scans are reported to be a valuable tool for the detection of pituitary adenomas [2-4]. This case clearly showed that FDG-PET is also useful for re-evaluation of the disease after surgery. PET scans are recommended for patients with equivocal pituitary mass lesions on conventional MRI, and for follow-up examinations after surgery.
一位 55 岁女性出现肢端肥大症的体征，被转至我院。内分泌检查显示，她的生长激素（GH；5.54ng/ml；正常值范围：0.66-3.68ng/ml）和胰岛素样生长因子-I（IGF-I；508ng/ml；正常值范围：37-266ng/ml）水平升高，口服葡萄糖耐量试验（oGTT；谷值 GH 3.66ng/ml）后血清 GH 不完全抑制，以及促甲状腺激素释放激素（TRH）激发试验的 GH 反应反常（峰值 GH 38.9ng/ml）。动态磁共振成像（MRI）提示其垂体左份有一个鞍内肿块病变（5.9x2.8mm）（图 1a，上排）。F-18 氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）成像清楚地显示了局部但明显的 FDG 摄取（图 1a，下排），与 MRI 上怀疑的肿瘤定位一致。肿瘤通过经蝶窦手术切除。随后的组织学分析证实了 GH 分泌性垂体腺瘤的诊断。切除后，血清 IGF-I 水平降至正常范围（178ng/ml），oGTT 时血清 GH 被适当抑制（谷值 GH 0.30ng/ml），提示获得了完全切除[1]。尽管术后变化使得 MRI 难以检测到任何残留病变（图 1b，上排），但术后 FDG-PET 未见异常 FDG 摄取（图 1b，下排）。据报道，PET 扫描是检测垂体腺瘤的一种有价值的工具[2-4]。本病例清楚地表明，FDG-PET 对于术后疾病的再评估也很有用。建议对常规 MRI 上有可疑垂体肿块病变的患者进行 PET 扫描，并在手术后进行随访检查。
