SUN-162 Isolated Primary Pigmented Micronodular Adrenal Disease. Unilateral or Bilateral Adrenalectomy? Two Cases Report

Background: Isolated primary pigmented nodular adrenal disease (i-PPNAD) is a particular case of micronodular bilateral hyperplasia (MiBAH) leading to Cushing syndrome (CS). We present two patients with i-PPNAD who undergone unilateral adrenalectomy with different disease outcomes. Case 1: A 56 yo man presented with typical signs and symptoms of CS, including central weight gain, proximal muscle weakness, hypertension and marked osteoporosis. A biochemical investigation showed an assessment of late-night salivary cortisol - 23 nmol/l (n <9), 24h urinary free cortisol (UFC)- 1206 nmol/24h (n-60–413). The 1 mg DST showed post-DST cortisol 617 nmol/l (n<50). ACTH concentration was suppressed at 1.1 pg/ml (n-7–66). Adrenal CT-scan was normal. PPNAD was assumed and the screening for Carney complex components was negative. After left adrenalectomy, histological examination confirmed the diagnosis of PPNAD. However, biochemical remission wasn’t achieved: postoperative UFC-860 nmol/24h. Thus, the right adrenalectomy was conducted. Case 2: A 40 yo female presented with long term drug-corrected (beta-blockers, ACE inhibitor) arterial hypertension, menstrual dysfunction and clinical features of CS (central obesity, proximal muscle weakness, hirsutism), without osteoporosis. Baseline hormonal evaluation documented slightly increased level of salivary cortisol- 9,8 nmol/l (n <9), post 1 mg DST cortisol - 470 nmol/l (n<50) and ACTH-concentration below detection <1 pg/ml (n-7–66). However, UFC was normal – 215 nmol/l (n-60–413). Abdominal CT-scan revealed micronodular hyperplasia of the left adrenal and was suggestive of possible right adrenal gland hyperplasia. We performed left adrenalectomy. In the early postoperative period, adrenal insufficiency was diagnosed and thus it required hydrocortisone replacement. Discussion: We obtained two opposite results: in case 1, an expected remission after unilateral adrenalectomy was not achieved, while patient No.2 developed adrenal insufficiency, which was a more favourable prognostic sign and attested to the successful outcome of surgical treatment. A possible explanation of the ineffectiveness of surgical intervention in patient No.1 was primary more severe hypercortisolism. It is also necessary to take into account that according to the CT data of the patient No.1, both adrenal glands were within normal ranges and did not differ from one another, while in the patient No.2, the lesion was more prominent on the right side. Conclusion: Diagnostic of i-PPNAD and choice of intervention can be precarious, consequently more studies are needed to define to which patients unilateral adrenalectomy could be an efficient treatment modality. It is possible to perform unilateral adrenalectomy with subsequent assessment of cortisol levels, in case of lack of remission the contralateral adrenalectomy is required.