單側腎上腺腫瘤切除術後產生的腎上腺素機能不全 - 病例報告

趙梓辰¹、余麗嬌²

台北慈濟醫院  ¹外科部泌尿科，²內科部內分泌及新陳代謝科

Postoperative adrenal insufficiency in a case with co-secretion of aldosterone and cortisone adrenal adenoma

Tze-Chen Chao¹, Leay-Kiaw Er²

¹Division of Urology, Department of Surgery, and ²Division of Endocrinology and Metabolism, Department of Internal Medicine, Taipei Tzu Chi Hospital, New Taipei City, Taiwan

Introduction:

Primary aldosteronism (PA) is the most common etiology of secondary hypertension, affecting 3%–5% of the general hypertensive population. PA is related to higher cardiovascular events, higher risk of renal failure due to renal fibrosis, and diabetes mellitus. Unilateral adenomas are generally treated with surgery rather than long-term mineralocorticoid receptor antagonists. However, some of the patients developed adrenal insufficiency (AI) after unilateral adrenalectomy in PA. Herein, we presented a case initially diagnosed as PA had AI after surgical treatment.

Case presentation:

A 52-year-old female patient has hypertension, stage 3 chronic kidney disease, and hypokalemia for more than 10 years. Initial serum aldosterone and plasma renin activity (PRA) were 55 ng/dl and 0.7 ng/ml/h, respectively. Abdominal computed tomography scan revealed a 1.7 × 2.2 cm left adrenal tumor. PA was impressed. The patient preferred medical treatment rather than surgical resection until 10 years later. Postoperative course at hospital was uneventful. Postoperative hydrocortisone replacement treatment lasted for 1 week after discharge.  The patient’s blood pressure after surgery decreased from 145/97 to 125/87 mmHg.

The patient subsequently had several episodes of near fainting while walking one month after the adrenalectomy. She also complained diarrhea and persistent body weight loss. The patient had gradually increased hyperkalemia in the serial follow up. Three months after the surgery, the patient was sent to hospital due to persistent chest tightness and dizziness for 2 days. At ER, BP was 95/27 mmHg. EKG revealed V2-V3 T wave inversion. The patient’s serum troponin-I level was 7.29 μg/L. She also had hyperkalemia (6.6 mg/dL). Under the impression of Non-ST elevated myocardial infarction, the patient was admitted to intensive care unit. Coronary angiogram showed no stenosis of coronary arteries. A permanent pacemaker was implanted since the patient experienced collapse due to complete AV block with a very long pause on admission day 2. Adrenal function test showed high ACTH (230 pg/mL), low morning cortisol (9.59 μg/dL), normal aldosterone (14.7 ng/dl), and low PRA (0.72 ng/ml/h). Postoperative AI was then impressed. The patient received cortisol and fludrocortisone supplement. Symptoms gradually improved after 3 years follow up. Further gene analysis showed somatic mutation of KCNJ5 gene.

Discussion:

Incidence of AI after unilateral adrenalectomy in PA was 27 %. It was initially regarded as solely a transient phenomenon. However, occasional prolong AI was reported in PA. Our patient presented with persistent hypotension, general fatigue, and hyperkalemia after unilateral adrenalectomy. AI was not diagnosed until she had refractory hypotension with complete AV block. Co-secretion of aldosterone and cortisol adenoma was therefore suspected.

Since AI occurred in about half of the patients with subclinical hypercortisolism, co-secretion of aldosterone and cortisol adrenal adenoma started being a raised issue. Prevalence of co-secretion of aldosterone and cortisol was reported from 5 to 21 %. Two third of the patients were female. Typical presentations included resistant hypertension combined with electrolyte disorders. Seventy-four percent of the patients had subclinical hypercortisolism. Reported somatic gene mutation included KCNJ5, GNAS, PRKACA, CTNNB1, and APC in aldosterone and cortisone cosecreation tumor. Our patient carried a somatic KCNJ5 mutation, which was compatible with clinical findings. Current diagnostic work-up in primary aldosteronism usually does not include assessment for hypercortisolism. However, in patients with co-secretion of aldosterone and cortisone adrenal adenoma, incomplete survey may contribute to severe complications. Therefore, complete adrenal function work-up is necessary in patients with adrenal tumor. Proper treatment may be applied to co-secretion tumor with aldosterone and cortisol in order to prevent prolong AI.