Padmanabhan Hema
AACE Clin Case Rep. 2018 Nov 1;5(2):e164-e167. doi: 10.4158/ACCR-2018-0288. eCollection 2019 Mar-Apr.
A thymoma is a rare tumor of the anterior mediastinum and may be under the control of prolactin and growth hormone (GH), as well as GH-insulin-like growth factor 1 (IGF-1)-mediated paracrine and autocrine pathways. The following case report highlights the unexpected outcome in a patient with a mediastinal thymoma after pituitary surgery for a GH-producing macroadenoma.
A 58-year-old Caucasian man with a history of acromegaly caused by a pituitary macroadenoma presented with a mediastinal thymoma (proven by biopsy). The thymoma was monitored annually by imaging studies, as the patient was asymptomatic and had declined surgery. The octreotide scan was negative and tests ruled out a GH-releasing hormone (GHRH)-producing tumor. Transsphenoidal surgery for removal of the pituitary tumor was performed.
Following surgery, the patient's IGF-1 levels normalized and GH was adequately suppressed in an oral glucose tolerance test. Follow-up imaging after 6 weeks and 10 months of surgery showed the absence of a pituitary tumor and a marked reduction in size of the mediastinal thymoma.
In a patient with acromegaly and a thymoma, surgical treatment of the GH-producing tumor might be expected to cause a reduction in thymoma size. Therefore, such tumors in patients with acromegaly may simply be monitored clinically.
胸腺瘤是前纵隔的一种罕见肿瘤，可能受催乳素和生长激素（GH）以及GH-胰岛素样生长因子1（IGF-1）介导的旁分泌和自分泌途径的控制。以下病例报告强调了一名患有纵隔胸腺瘤的患者在因分泌GH的大腺瘤接受垂体手术后出现的意外结果。
一名58岁的白种男性，有垂体大腺瘤导致肢端肥大症的病史，出现纵隔胸腺瘤（活检证实）。由于患者无症状且拒绝手术，每年通过影像学检查监测胸腺瘤。奥曲肽扫描为阴性，检查排除了分泌生长激素释放激素（GHRH）的肿瘤。进行了经蝶窦手术以切除垂体肿瘤。
手术后，患者的IGF-1水平恢复正常，口服葡萄糖耐量试验中GH得到充分抑制。手术后6周和10个月的随访影像学检查显示垂体肿瘤消失，纵隔胸腺瘤大小明显缩小。
对于患有肢端肥大症和胸腺瘤的患者，手术治疗分泌GH的肿瘤可能会使胸腺瘤大小缩小。因此，对于肢端肥大症患者的此类肿瘤，可仅进行临床监测。
