Ozkaya Mesut, Yuzbasioglu Mehmet Fatih, Bulbuloglu Ertan, Bakaris Sevgi, Oksuz Hafize, Gisi Kadir, Onder Ahmet
Departments of General Surgery, Sutcu Imam University Medical Faculty, Kahramanmaras, Turkey.
Cases J. 2008 May 25;1(1):10. doi: 10.1186/1757-1626-1-10.
Adrenal incidentaloma can be described as adrenal lesions that are incidentally diagnosed during abdominal laparotomy or any abdominal screening without prior suspicion of adrenal disease. It is important to diagnose adrenal lesions to learn if they are hormonally active or malignant. The most common clinical sign of pheochromocytoma is sustained or paroxysmal hypertension, and the most common symptoms are headache, excessive truncal sweating, and palpitation. In some cases, the clinical symptoms are not clear. Roughly 70% of adrenal incidentalomas are non-functional. A small group of 5-7% of the functional ones (30%) may exist as pheochromocytoma. Ten percent of pheochromocytoma cases are diagnosed incidentally during computed tomography (CT) or magnetic resonance imaging (MRI) screenings for other reasons. The most frequent symptom of the pheochromocytoma is hypertension, and 90-100% of cases exhibit it. The literature indicates that incidental pheochromocytoma cases that are smaller than 1 cm have no clinical symptoms. Rarely, some large pheochromocytoma cases do not show any clinical symptoms, and it is difficult to diagnose very small ones.
A 45-year-old male patient experienced an epigastric ache and distended stomach for 7 years. The serum cortisol level was 19.2 ng/dL (normal range: 5-20 ng/dL), and urinary free cortisol excretion was 25.00 mug/24 h (normal range:10.00-100.00 mug/24 h). The serum basal level of adrenocorticotropic hormone (ACTH) was 21 pg/mL (normal range: 9 to 52 pg/mL). Plasma cortisol was under 1.00 mug/dL after low dose (1 mg) overnight dexamethasone suppression test. 24 hours urinary catecholamines level were vanil mandilic acid (VMA) 8.90 mg/day (normal range, 3 to 90 mg/day), metanefrin 330 mug/day (normal range, 52 to 341 mug/day), epinefrin 13 mug/day (normal range, 2 to 24 mug/day), norepinefrin 41 mug/day (normal range; 15 to 100 mug/day). During abdominal ultrasonography (USG), a tumor was diagnosed in the right perirenal space. A regular-shaped mass (dimension 36 x 35 x 35 mm) with a homogeneous and solid structure was diagnosed in CT. The density of the mass was 80 Hounsfield units (HU) in postcontrast CT. The patient was given a diagnosis of a non-functional adrenal incidental lesion, underwent a right adrenalectomy. Histopathological data correlated with pheochromocytoma as well
Pheochromocytoma can be diagnosed by establishing an increase in catecholamines and metabolites in the plasma and urine. The level of catecholamines and metabolites in the plasma and urine provide 95% of the evidence of the disease. Because the dimensions of the lesion were large and the HU was very clear, the patient was underwent surrenalectomy. During laboratory investigation, there was no evidence of abnormality; we, therefore, think that these cases can be named sublaboratory pheochromocytoma.
肾上腺偶发瘤可定义为在腹部剖腹手术或任何腹部筛查过程中偶然发现的肾上腺病变，术前并无肾上腺疾病的怀疑。诊断肾上腺病变以了解其是否具有激素活性或是否为恶性至关重要。嗜铬细胞瘤最常见的临床体征是持续性或阵发性高血压，最常见的症状是头痛、躯干多汗和心悸。在某些情况下，临床症状并不明显。大约70%的肾上腺偶发瘤无功能。一小部分（5 - 7%）有功能的肾上腺偶发瘤（占30%）可能为嗜铬细胞瘤。10%的嗜铬细胞瘤病例是在因其他原因进行计算机断层扫描（CT）或磁共振成像（MRI）筛查时偶然发现的。嗜铬细胞瘤最常见的症状是高血压，90 - 100%的病例有此症状。文献表明，小于1厘米的偶发嗜铬细胞瘤病例无临床症状。极少数情况下，一些大的嗜铬细胞瘤病例也无任何临床症状，且极难诊断非常小的嗜铬细胞瘤。
一名45岁男性患者上腹部疼痛和胃部胀满7年。血清皮质醇水平为19.2 ng/dL（正常范围：5 - 20 ng/dL），尿游离皮质醇排泄量为25.00 μg/24小时（正常范围：10.00 - 100.00 μg/24小时）。促肾上腺皮质激素（ACTH）血清基础水平为21 pg/mL（正常范围：9至52 pg/mL）。低剂量（1毫克）过夜地塞米松抑制试验后血浆皮质醇低于1.00 μg/dL。24小时尿儿茶酚胺水平：香草扁桃酸（VMA）8.90毫克/天（正常范围，3至90毫克/天），间甲肾上腺素330 μg/天（正常范围，52至341 μg/天），肾上腺素13 μg/天（正常范围，2至24 μg/天），去甲肾上腺素41 μg/天（正常范围；15至100 μg/天）。腹部超声检查（USG）时，在右肾周间隙诊断出一个肿瘤。CT检查发现一个形状规则的肿块（尺寸为36×35×35毫米），结构均匀且为实性。增强CT扫描时肿块密度为80亨氏单位（HU）。该患者被诊断为无功能肾上腺偶发病变，接受了右肾上腺切除术。组织病理学检查结果也符合嗜铬细胞瘤。
嗜铬细胞瘤可通过检测血浆和尿液中儿茶酚胺及其代谢产物升高来诊断。血浆和尿液中儿茶酚胺及其代谢产物水平为该疾病提供了95%的诊断依据。由于病变尺寸较大且HU值非常明确，患者接受了肾上腺切除术。实验室检查期间未发现异常证据；因此，我们认为这些病例可称为亚实验室嗜铬细胞瘤。
