History: A 58-year-old woman presents to her gastroenterologist with a long-standing history of intermittent abdominal pain that has been present for more than two years.
病史：58岁女性，因间歇性腹痛两年多就诊于消化科。
Findings
CT images demonstrate the following:
- Hyperenhancing mass in the right adrenal measuring 1.5 cm (orange arrow)
- Multiple hyperenhancing submucosal masses in the small bowel (red arrows)
- Multiple cutaneous nodules in keeping with cutaneous neurofibromas (yellow arrows)
CT表现（如下图箭头所示）：
右肾上腺1.5cm大小的富血供结节灶；
小肠多发明显强化的粘膜下肿物；
多发皮肤结节（皮肤神经纤维瘤）。
Differential Diagnosis
Multiple small-bowel masses：
- Most commonly related to hematogenous metastases — e.g., melanoma
- Polyposis syndromes such as Peutz-Jeghers syndrome
- Gastrointestinal stromal tumors (GIST)
- Carcinoid tumor
Adrenal mass：
- Adrenal adenoma
- Pheochromocytoma
- Adrenal metastasis
- Ganglioneuromas
鉴别诊断
多发小肠肿物：
- 多见于血行转移瘤（例如：黑色素瘤）
- 家族性黏膜皮肤色素沉着胃肠道息肉病（黑斑息肉综合征）
- 胃肠道间质瘤（GIST）
- 类癌
肾上腺肿物：
- 腺瘤
- 嗜铬细胞瘤
- 转移瘤
- 节细胞神经瘤
Diagnosis: Small-bowel GISTs and adrenal pheochromocytoma in the setting of neurofibromatosis type 1 (NF1)
诊断：神经纤维瘤病1型，合并小肠GIST及肾上腺嗜铬细胞瘤
Discussion
Neurofibromatosis type 1 (NF1)
NF1 is an autosomal dominant neurocutaneous disorder defined by the presence of cafe au lait spots, axillary freckling, plexiform neurofibromas, skeletal dysplasias, and iris hamartomas (Lisch nodules). The genetic mutation of the NF1 leads to abnormal tumor suppression, leading to a variety of benign and malignant tumors. The full spectrum of tumors in NF1 is beyond the scope of the text. Approximately 10% to 25% of patients with NF1 have abdominal tumors. The primary categories of abdominal tumors are neurogenic, neuroendocrine, mesenchymal, embryonal, and miscellaneous. It is not uncommon for patients to have multiple tumors, as this case illustrates.
神经纤维瘤病1型（NF1）是一种常染色体显性遗传的神经皮肤异常，表现为牛奶咖啡斑、腋窝雀斑、丛状神经纤维瘤、骨骼发育不良、虹膜错构瘤（Lisch结节）。NF1基因突变导致肿瘤抑制异常，可发生各种各样的良性和恶性肿瘤。NF1发生的肿瘤远超过文本所述范围。大约10%-25%的NF1患者有腹部肿瘤，最常见的是神经源性的、神经内分泌的、间叶源性的、胚胎性的及其它。如本例所见，存在多个肿瘤并不少见。
Benign neurofibromas are by far the most common tumor involving the gastrointestinal (GI) tract in NF1 patients. GISTs, leiomyomas, leiomyosarcomas, carcinoids, and ganglioneuromas occur within the GI tract. Multiplicity is a common feature in GI tract neurofibromas and GISTs. GISTs in NF1 patients are morphologically and immunohistochemically identical to tumors that occur in non-NF tumors. GISTs can be malignant, benign, or uncertain malignant potential whether they occur in NF1 or non-NF1 patients. Unlike neurofibromas, GISTs occur exclusively within the small bowel as seen in the current case. Although not seen in the current case, intratumoral hemorrhage, necrosis, and degeneration/necrosis can be seen.
NF1患者胃肠道最常见的肿瘤是良性神经纤维瘤。GISTs、平滑肌瘤、平滑肌肉瘤、类癌、节细胞神经瘤也可以发生于胃肠道。胃肠道神经纤维瘤及GISTs的常见特点是多发。NF1患者GISTs与非NF1患者的在形态学及免疫组化上是相同的。无论发生于NF1患者还是非NF1患者，GISTs都可以是恶性、良性或具有恶性潜能的。与神经纤维瘤不同，GISTs仅见于小肠，可见瘤内出血、坏死及变性，本例未见上述征象。
Finally, NF1 patients have a higher than baseline risk of developing pheochromocytomas. The presence of a well-circumscribed, markedly enhancing adrenal mass in an NF1 patient is pathognomonic for a pheochromocytoma. While more than 80% of patients have unilateral pheochromocytoma, up to 10% of patients may have bilateral or extra adrenal tumors. The majority of patients with pheochromocytomas are symptomatic due to catecholamine excess, often with headaches, palpitations and diaphoresis. As pheochromocytomas enlarge, they may demonstrate necrosis, hemorrhage, and cystic degeneration. Ganglioneuromas, benign neoplasms arising from sympathetic ganglia, can occur focally in the adrenal, mimicking pheochromocytomas. Ganglioneuromas may even rarely secrete catecholamines, further confusing diagnostic differentiation.
NF1患者易合并嗜铬细胞瘤，表现为边界清楚、明显强化的肾上腺肿物，其中80%为单侧的，10%为双侧或肾上腺外的。由于儿茶酚按升高，大部分嗜铬细胞瘤患者有头痛、心悸、出汗等症状。当嗜铬细胞瘤体积较大时，易出现坏死、出血、囊变。节细胞神经瘤及起源于交感神经的良性肿瘤也可见于肾上腺，表现类似嗜铬细胞瘤，极少数节细胞神经瘤也可分泌儿茶酚按，诊断时较难鉴别。
神经纤维瘤病1型和2型诊断标准
1987年美国NIH制定了诊断标准：
NF1
1） 6个或以上的牛奶咖啡斑，青春期前最大直径5mm以上，青春期后15mm以上；
2） 2个或以上任意类型神经纤维瘤或1个丛状神经纤维瘤；
3） 腋窝或腹股沟褐色雀斑；
4） 视神经胶质瘤；
5） 2个或以上Lisch结节，即虹膜错构瘤；
6） 明显的骨骼病变：如蝶骨发育不良，长管状骨皮质菲薄，伴有假关节形成；
7） 一级亲属中有确诊NF1的患者。
上述标准符合2条或以上者可诊断NF1。
NF2
1） 双侧听神经瘤；
2） 有NF2家族史（一级亲属中有NF2患者），患单侧听神经瘤；
3） 有NF2家族史（一级亲属中有NF2患者），患者有以下病变中的2中：神经纤维瘤、脑膜瘤、胶质瘤、雪旺氏细胞瘤、青少年晶状体后囊浑浊斑。
上述标准符合1项即可诊断NF2。