A 45-year-old female with classical presentation of hypercortisolism, was transferred from the Department of Urology in Shanghai 9th hospital. The patient was diagnosed with right adrenal adenoma ten years ago owing to weight gain, hypertension and right lumbar pain. She accepted the surgery of right adrenal adenoma resection. But the cushingoid feature, such as excessive weight gain, central obesity and hypertension, etc., did not improve after the surgery. She experienced progressive weight gain from 45Kg to 95Kg in the past decade, with progressing edema in the face and lower limbs. Moreover, she took anti-hypertensive drugs with poorly control of blood pressure by Nifedipine Controlled-release Tablets (60mg/day), Olmesartan Medoxomil (20mg/day) and Metoprolol Tartrate Tablets (25mg/day). Hirsutism and acne also developed gradually with menstrual cycle disturbances. Her family history was negative for similar presentations.
Upon admission, she showed the typical hypercortisolism appearance, including moonlike face, abdominal fat deposits, dorsal and supraclavicular fat pads, facial acne, slight hirsutism (Fig. 1A). She weighed 95Kg and her height was 159cm with body mass index (BMI) 37.6kg/m2. High blood pressure (165/101mmHg) was noticed with the heart rate of 78 bpm under three or four types of anti-hypertension drugs. Black and brown moles were observed on the patient’s face and pigmented skin was notice in the hypochondria region (Fig. 1C, 1D). Wide purple striae was observed on the skin of abdomen, waist and thighs (Fig. 1E). Ecchymoses and pitting edema were also found with the bilateral lower limbs.
The laboratory tests revealed that morning cortisol level was close to the upper limit of the reference range (23.2ug/dl, ref: 5-25ug/dl) with disturbed circadian rhythm of cortisol secretion (4PM 18.8ug/dl, 0AM 21.7ug/dl, ref: 2.5-12.5ug/dl), elevated urinary free cortisol (UFC) level (171.7ug/24h, ref: 21-111ug/24h). But morning serum ACTH levels showed significantly reduced or undetectable (8AM 11.7pg/ml, 4PM 34.7pg/ml, 0AM 19.3pg/ml, ref: 0-46pg/ml). High-dose dexamethasone suppression test (HDDST) (8mg dexamethasone orally overnight) failed to suppress serum cortisol level (23.2→20.7ug/dl) and UFC level (171.7→147.84ug/24h), indicating the high level of cortisol autonomously secreted by bilateral adrenal glands. Serum androgen levels including testosterone (T-2, 0.35ng/ml, ref: 0.11-0.57ng/ml), androstenedione (AD, 2.95ng/ml, ref: 0.3-5.5ng/ml) seemed to be in the reference range. Normal aldosterone level 143.85pg/ml (ref: 65.2-295.7pg/ml) is helpful to exclude primary hyperaldosteronism (PHA). The detailed laboratory tests are listed in Table 1. Meanwhile, multiple micronodules in bilateral adrenal glands were discovered by computed tomography (CT) scan of adrenal with the largest size of 8mm on the right side (Fig. 2A, 2B). Echocardiography showed mild left ventricular hypertrophy without cardiac myxoma. Pituitary MRI showed partial empty sella. Ultrasound of thyroid was found to be normal with no signs of the nodule.
Sequencing of the PRKAR1A gene
The patient underwent genetic diagnosis by Whole-exome sequencing (WES). The heterozygous missense mutation NM_212472.2: c.1A>G, p.(Met1Val) in the start codon of PRKAR1A was identified, which is validated by the Sanger sequencing of PCR products (Fig. 2E). This variant was not present in dbSNP135, the 1000 genomes project nor ExAC database. Moreover, mutation analysis of PRKAR1A gene was negative in both her parents and daughter, who have no similar presentations (Fig. 2F).
Based on her typical manifestations, the most likely diagnosis was considered as hypercortisolism caused by PPNAD. However, severe obesity and poorly controlled hypertension tended to be the barrier of surgical anesthesia. Then the patient accepted Mitotane therapy to suppress hypercortisolism provisionally. After seven months of low-dose Mitotane intake (The initial dose was 250 mg/day for one week, then gradually increased to 500 mg/day), her body weight reduced to 80kg and hypertension improved significantly. Serum cortisol (8AM 23.2→16.0ug/dl, 4PM 18.8→14.4ug/dl, 0AM 21.7→15.3ug/dl) and UFC levels (171.7→25.68ug/24h) showed decreasing (Table 1 and Fig. 3). Her blood pressure could be controlled with Nifedipine, Olmesartan and Metoprolol. And the size of adrenal nodules was observed to be reduced significantly by CT scan (Fig. 2C). Subsequently, the patient accepted laparoscopic right adrenalectomy. Considering the existence of autonomous secretion left adrenal, serum cortisol level reduced to 9.0ug/dl on the next day after surgery (Table 1 and Fig. 3). Mitotane was suggested to maintain 250mg/day. But the patient discontinued this medicine one month later.
Pathological analysis and immunohistochemistry (IHC)
Pathological analysis of the resected adrenal gland was consistent with the features of PPNAD. Multiple pigmented cortical nodules composed of fine granular pigment cells filled with lipofuscin and atrophic inter-nodular cortex were observed by Hematoxylin-eosin staining (Fig. 4A, 4B). By using immunohistochemistry (IHC), the expression of PRKAR1A was found to be remarkably reduced, compared with the peri-tumorous normal tissues from a patient with adrenal adenoma, indicating that the mutation located in the start codon impairs the translation of the PRKAR1A (Fig. 4C, 4D).
Three months after laparoscopic right adrenalectomy, the patient’s blood pressure was well controlled with the anti-hypertensive drugs. Her ACTH levels were still less than 10pg/ml, whereas the cortisol level showed significantly reduced but disturbed circadian rhythm of cortisol (8AM 6.65 ug/dl, 4PM 6.87 ug/dl, 0AM 6.15ug/dl) (Table 1 and Fig. 3). Meanwhile, the remarkable decrease of androgen levels including testosterone (T-2, 0.35→0.15ng/ml, ref: 0.11-0.57ng/ml), androstenedione (AD, 2.95→0.96ng/ml, ref: 0.3-5.5ng/ml) and dehydroepiandrosterone sulfate (DHEA-S, 75.6→<15ug/dl, ref: 35-430ug/dl) were noticed, suggesting the suppressed hormone secretion of the reticular zone of the left adrenal gland.
One year later, the patient went to our hospital to seek the comprehensive assessment of her condition again. Her body weight reduced to 70Kg continuously in this year, with 25kg weight loss compared with that of the first visit (Fig. 1B). Her blood pressure could be well controlled by Valsartan, Nefidipine and Metoprolol. Wide purple striae was obviously lighter than before (Fig. 1F). The cortisol level of 8 AM was found to be in the reference range, but the circadian rhythm of cortisol was mildly abnormal (8AM 14.5 ug/dl, 4PM 9.48 ug/dl, 0AM 10.6ug/dl) (Table 1 and Fig. 3). And ACTH level showed less than 10pg/ml. The cortisol level was found to be 16.4 ug/dl after low-dose dexamethasone suppression test (LDDST). CT scan showed the left adrenal nodule with the size of 5mm (Fig. 2D). Considering the patient was reluctant to accept the left adrenalectomy, low dosage intake of Mitotane (250mg/day) was suggested.