SAT330 Recurrence of Acth Independent Cushing Syndrome In Patient With Previously Operated On For Primary Bilateral Macronodular Adrenal Hyperplasia And Co-existence Of Papillary Thyroid Carcinoma

Disclosure: N. Vashakmadze: None. D. Nikoleishvili: None. Background: Cushing syndrome is a rare and usually sporadic endocrine disorder. Herein we describe a case of ACTH-independent Cushing syndrome and ACTH-dependent Cushing disease in non-identical twins. Moreover, recurrence of Cushing syndrome after 25 years of non-complete resection of adrenal glands and co-existence of papillary thyroid cancer. Clinical Case: A 57-year woman presented with hypertension, depression, easy bruising, proximal muscle weakness, fatigue, and facial plethora. According to the patient, Cushing’s syndrome caused by bilateral macronodular adrenal hyperplasia was diagnosed in 1997. Surgical treatment - left adrenalectomy and right adrenal gland resection was performed. She was receiving HRT during the first 6 months, since then she was not receiving HRT and her cortisol was normal. It is extremely interesting that her nonidentical twin sister was diagnosed with ACTH-dependent Cushing disease in 2006 and was successfully treated with transsphenoidal surgery. In 2019 patient was diagnosed with papillary thyroid cancer (PTC), thyroidectomy was performed and multifocal PTC pT1b(m)N0M0 was diagnosed. Patient received adjuvant therapy with 80 mCi of RAI. In 2019 cortisol and ACTH levels were routinely evaluated, ACTH was undetectable <3 ng/dl (N: 7.2-63); 1 mg dexamethasone suppression test showed no suppression of cortisol 116 ng/ml (N: <1.8 ng/ml). However, patient did not consult an endocrinologist with the results of the mentioned investigations. She admitted to our clinic in December 2022 with above-mentioned complains to determine the tactics of further investigation/treatment. The data obtained during our consultation was consistent to recurrence of Cushing syndrome: midnight salivary cortisol– 0.46 mcg/dl (0.02-0.34), ACTH– 4.2 ng/l (7.2-63), 1 mg of dexamethasone suppression test – 217 nmol/l (<50). CT showed right adrenal noduls (2.5 cm and 1.2 cm). These data confirmed the diagnosis of recurrence of Cushing’s syndrome and right adrenalectomy with steroid coverage and postoperative hormone replacement therapy was recommended. Other data showed normal OGTT, moderate hypercholesterolemia, taking into account Cushing’s syndrome and smoking, statins were initiated. DXA showed osteoporosis (forearm T-score = -3.9 SD). 25(OH)D3 – 22.35 ng/ml, Ca – 1.09 mmol/l (1.1-1.3). Denosumab, calcium and vitamin D supplements were started to the patient. In addition, TSH was markedly suppressed on 125 mcg LT4 therapy, TSH – 0.005 mIU/l (0.4-3.8); Tg <0.17 g/l, anti-Tg - N and neck ultrasound was normal, that is consistent with excellent response and the target TSH was established 0.5-2.0 mIU/l. The dose of LT4 was reduced to 100 mcg. Conclusion: To our knowledge existence of Cushing syndrome and Cushing disease in non-identical twins has not been reported yet. Also, co-existence of Cushing syndrome and thyroid cancer is rare, and no connection is established yet. Presentation: Saturday, June 17, 2023