Abstract:

Background The presence of ganglion cells within an endocrine pituitary adenoma in sellar region is rare, and is usually diagnosed as "mixed gangliocytoma-pituitary adenoma". Due to lack of radiological characteristics, it is very difficult to make an accurate diagnosis preoperatively. Herein we describe one case of unusual mixed gangliocytoma - growth hormone (GH) secreting pituitary adenoma in sellar region and review related literatures, so as to summarize the clinicopathological characteristics and improve the diagnosis and differential diagnosis of this tumor. Methods and Results A 28 - year - old female presented with headache and blurred vision for 8 months. She also complained of acromegaly and amenorrhea. Head CT and MRI examinations showed a sellar and suprasellar mass with clear boundary compressing the optic chiasm and buttom of the third ventricle. The mass exhibited isointense signal or mild hypointensity on T₁WI and mild hyperintensity on T₂WI with heterogeneous enhancement on the contrast MRI. The tumor was removed totally. The histological sections demonstrated two parts of intermixed areas. One part of areas was marked by a proliferation of scattered gangliocyte - like cells arranged in a fibrillary background. Other areas were marked by a sheet - like or locally papillary proliferation of round and oval cells. Immunohistochemically, cytoplasm of gangliocyte-cells were diffusely positive for synaptophysin (Syn), and negative for adenohypophysial hormones; cytoplasm of round and oval cells were diffusely positive for Syn, and almost 30% cells were positive for GH, and negative for other neurohypophysial hormones. A final diagnosis of mixed gangliocytoma-GH secreting pituitary adenoma in sellar region (WHO grade Ⅰ) was made. The patient did not receive postoperatively adjuvant therapy and was followed-up for one year, without any neurological deficit or signs of recurrence. Conclusions Mixed gangliocytoma - pituitary adenoma is extremely rare and a definite diagnosis should be made under microscopy examination. Since the histogenesis of this tumor suggests that the uncommitted stem/progenitor cells consist of both adenohypophysial and neuronal characteristics and are capable of giving rise to pituitary adenoma with neuronal component, a diagnostic term of "pituitary adenoma with ganglionic differentiation" is suggested for this independent entity rather than collision tumor combined by two separate tumors.

Key words: Ganglioneuroma, Growth hormone - secreting pituitary adenoma, Sella turcica, Immunohistochemistry, Pathology

摘要：

研究背景 发生于垂体的混合性神经节细胞瘤-垂体腺瘤临床罕见，由于其缺乏特征性影像学表现，易误诊为垂体腺瘤，是术前诊断鞍区肿瘤的难点。本文回顾分析1 例鞍区混合性神经节细胞瘤-生长激素垂体腺瘤患者的诊断与治疗经过，结合文献对此类临床少见垂体肿瘤的临床病理学特征进行分析，以期提高诊断与鉴别诊断能力。方法与结果 女性患者，28 岁，临床主要表现为反复头痛伴视物模糊8 月余，以及肢端肥大和闭经表现。头部CT 和MRI 显示鞍内和鞍上不规则占位性病变，呈T₁WI等或稍低信号、T₂WI 稍高信号，增强扫描病灶呈明显不均匀强化，边界清晰，压迫视交叉和第三脑室底部。手术全切除肿瘤。组织学形态观察，肿瘤组织分为两部分结构，一部分为不规则簇状排列的神经节细胞样细胞分布于神经纤维背景中，另一部分为片状排列或局部乳头状结构的圆形和卵圆形细胞，两部 分结构相互混杂。免疫组织化学染色，神经节细胞样细胞区域肿瘤细胞胞质突触素（Syn）呈弥漫性强阳性，腺垂体激素呈阴性；圆形细胞区域肿瘤细胞胞质Syn 呈弥漫性阳性，约30%肿瘤细胞生长激素呈阳性，其余神经垂体激素呈阴性。最终病理诊断为（鞍区）混合性神经节细胞瘤-生长激素垂体腺瘤（WHOⅠ级）。术后未予放射治疗，随访1 年，临床症状明显改善，肿瘤未复发。结论 鞍区混合性神经节细胞瘤-垂体腺瘤临床罕见，鉴于目前大多支持该肿瘤是起源于垂体干/祖细胞、具有内分泌细胞和神经元双向分化的独立肿瘤实体，故建议采用“伴神经节细胞分化的垂体腺瘤”的诊断术语，应注意与两种独立肿瘤形成的碰撞瘤相鉴别。

关键词: 神经节瘤, 分泌生长激素的脑垂体腺瘤, 蝶鞍, 免疫组织化学, 病理学