Images in Nephrology (Section Editor: G. H. Neild)
NDT Nephrology Dialysis Transplantation
PLUS
A rare cause of secondary hypertension
Chin-Chi Kuo1, Vin-Cent Wu1, Ching-Wei Tsai2, Fan-Fen Wang3, Shih-Chieh Chueh4 and Kwan-Dun Wu1
1Department of Internal Medicine, National Taiwan University Hospital, 2Department of Internal Medicine, China Medical University Hospital Taipei Branch, 3Division of Endocrinology and Metabolism, Taipei City Hospital Yang-Ming Branch and
4Department of Urology, National Taiwan University Hospital, Taipei, Taiwan
Keywords: adrenocortical carcinoma; aldosteronism
A 20-year-old obese man was referred to our hospital with 1-year hypertension and mild hypokalaemia (potassium, 3.3 mmol/l). The ratio of postcaptopril plasma aldosterone concentration (PAC) to plasma renin activity (PRA) was high [25.8 (ng/dl)/0.33 (ng/ml/h) = 77.4]. The PAC post- saline loading test remained high (28.1 ng/dl). The 24-h urinary catecholamines and VMA (vanillyl mandelic acid) were within normal limits. Primary aldosteronism was di- agnosed, and a computed tomography disclosed an iso- dense mass with a maximal diameter of 4 cm over the right adrenal gland (Figure 1). The patient then under- went right laparoscopic adrenalectomy. Grossly, a well- encapsulated 4.5 × 4.0 × 3.5 cm yellowish tumour with central necrosis was noted. Histologically, the tumour was composed of pleomorphic cells with high-grade nuclei, prominent nucleoli, and >1/3 of the tumour presenting patternless sheets of cells. Furthermore, the mitotic count was >5 in 50 high power fields with atypical mitotic fig- ures (Figure 2a and b). Adrenocortical carcinoma (ACC) was diagnosed according to the modified Weiss classifi- cation system [1]. Subsequent immunohistochemical stud- ies confirmed that the tumour was aldosterone producing (Figure 2c and d). Two months after the operation, PAC and
PRA were 32.7 ng/dl and 25.45 ng/ml/h, respectively, and the patient became normotensive.
ACCs are rare and account for an estimated 0.05- 0.2% of all malignancies [2]. Hormonally functioning tu- mours occur in ~50% of ACC patients. Nevertheless, the aldosterone-producing ACC are even rarer. There is a bi- modal occurrence by age, with a peak incidence at <5 years, and a second peak between 40 and 50 years [3]. The differ- entiation between benign and malignant neoplasms is often difficult by preoperative image. However, a tumour size of >4 cm should raise clinical suspicion of adrenocortical malignancy, even at a young age.
Acknowledgement. The authors would like to thank Dr Fan-Fen Wang for her medical technical support in immunohistologic staining. This report was financially supported by The Ta-Tung Kidney Foundation.
Conflict of interest statement. None declared.
References
1. Medeiros LJ, Weiss LM. New developments in the pathologic diagnosis of adrenal cortical neoplasms. A review. Am J Clin Pathol 1992; 97: 73-83
2. Wajchenberg BL, Albergaria Pereira MA, Medonca BB, et al. Adreno- cortical carcinoma: clinical and laboratory observations. Cancer 2000; 88: 711-736
3. Boushey RP, Dackiw AP. Adrenal cortical carcinoma. Curr Treat Options Oncol 2001; 2: 355-364
Received for publication: 8.12.08
Accepted in revised form: 29.12.08
@ The Author [2009]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org
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