Chan Nicole, Kaufman Ronald P, Farhat Nada, Kim Grace Y
Division of Endocrinology and Metabolism, Albany Medical College, Albany, New York, USA.
Department of Urology, Albany Medical College, Albany, New York, USA.
Endocrinol Diabetes Metab Case Rep. 2025 Sep 2;2025(3). doi: 10.1530/EDM-25-0027. Print 2025 Jul 1.
Pheochromocytomas are rare neuroendocrine tumors derived from adrenal chromaffin cells that result in hyperactivity of the sympathetic nervous system. We present the case of a patient with biochemical evidence of pheochromocytoma, but surgical pathology revealed absence of tumor. This is an 80-year-old female with a past medical history of metastatic follicular lymphoma and hypertension with an incidental 1.4 cm right-sided adrenal nodule noted on a PET-CT scan. Her hypertension was treated with three different antihypertensive agents. Subsequent imaging with non-contrast CT of abdomen and pelvis showed a right adrenal incidentaloma with 16 Hounsfield units. Abdominal MRI with and without contrast revealed atypical signal loss on the out-of-phase imaging. Plasma normetanephrines were approximately 2.4 times higher than the upper limit of normal. Her urinary normetanephrines were higher than the upper limit of normal, suggestive of pheochromocytoma. The patient proceeded with robotically assisted laparoscopic right adrenalectomy and postoperatively required vasopressors. Surgical pathology showed adrenal cortical hyperplasia and medullary infarction associated with fibrosis. However, the noted phases of necrosis with predominant fibrosis match the time interval between clinical diagnosis and surgical management. Postoperative metanephrines normalized 4 weeks after surgery, indicating successful surgical resection of autonomous secretion of metanephrines. This is the only known case of biochemical evidence of pheochromocytoma with no histologic evidence of tumor.
Biochemical evidence, clinical presentation and imaging studies of pheochromocytoma are crucial for its diagnosis. Due to the vascular nature of pheochromocytoma, there is a potential for the tumor to infarct. Plasma normetanephrines of greater than twice the upper limit of normal have high specificity for pheochromocytoma.
嗜铬细胞瘤是一种罕见的神经内分泌肿瘤，起源于肾上腺嗜铬细胞，可导致交感神经系统功能亢进。我们报告一例患者，其有嗜铬细胞瘤的生化证据，但手术病理显示无肿瘤。这是一位80岁女性，既往有转移性滤泡性淋巴瘤和高血压病史，在PET-CT扫描时偶然发现右侧肾上腺有一个1.4 cm的结节。她的高血压用三种不同的抗高血压药物治疗。随后的腹部和盆腔非增强CT成像显示右侧肾上腺偶发瘤，Hounsfield单位为16。腹部MRI平扫及增强扫描显示同相位成像时有非典型信号缺失。血浆去甲变肾上腺素比正常上限高约2.4倍。她的尿去甲变肾上腺素高于正常上限，提示嗜铬细胞瘤。患者接受了机器人辅助腹腔镜右侧肾上腺切除术，术后需要使用血管升压药。手术病理显示肾上腺皮质增生和髓质梗死伴纤维化。然而，观察到的以纤维化为主的坏死阶段与临床诊断和手术治疗之间的时间间隔相符。术后4周变肾上腺素恢复正常，表明成功手术切除了变肾上腺素的自主分泌。这是已知的唯一一例有嗜铬细胞瘤生化证据但无肿瘤组织学证据的病例。
嗜铬细胞瘤的生化证据、临床表现和影像学检查对其诊断至关重要。由于嗜铬细胞瘤的血管特性，肿瘤有梗死的可能性。血浆去甲变肾上腺素大于正常上限两倍对嗜铬细胞瘤具有高特异性。
