Endocrine Abstracts

Introduction: Statistical data show that in the etiological structure of ACTH-ectopic syndrome pheochromocytoma occupies one of the last places in terms of frequency of occurrence (from 2.8 to 5.6%) Its manifestations such as adrenal mass with ACTH-dependent hypercortisolism lead to significant difficulties in establishing the correct diagnosis.

Clinical Case: A patient with clinical manifestations of hypercortisolism underwent laboratory testing in October 2022: evening saliva cortisol - 220.6 nmol/l (0.5-9.65), evening serum cortisol -1548 nmol/l (64-327), 24-hour urine cortisol -12332.25 nmol/day (100-379); ACTH evening -204.1 pg/ml (2-25.5), morning -313.4 pg/ml (7.2-63.3). Brain MRI with contrast enhancement revealed a microadenoma (3×3.5 mm) in the posterior part of the adenohypophysis. A concomitant search for the source of ACTH ectopia was carried out. According to the abdomen CT: a lesion of the left adrenal gland measuring 37×30×46 mm, a malignant phenotype with a density of 42/49/69/60 HU (active/arterial/venous/delayed phases). Thebilateral selective sampling from the lower petrosal sinuses revealed the absence of thegradient of ACTH secretion (maximum on the right - 1.15; on the left - 1.10). SPECT-CT of the abdominal cavity in the left adrenal gland revealed a formation of soft tissue density measuring 39×30×49 mm, accumulating 99Tc-tectrotide, which confirmed moderately increased expression of somatostatin receptors. Thus, the data obtained supported the extrapituitary genesis of ACTH-dependent hypercortisolism due to pheochromocytoma which was confirmed by 24h-urine analysis - metanephrine - 1122.9 mg/day (25-312), normetanephrine - 1039.11 mg/day (35-445). Taking into account the rate of disease progression, a somatostatin analog (lanreotide autogel 120 mg s.c.) was administered once - without a significant decrease in ACTH secretion (from 313 pg/ml to 243 pg/ml). Ketoconazole 600 mg/day was also prescribed - no effect on 24-hour urine cortisol levels (>35.000 nmol/day). Treatment for complications of hypercortisolism was also initiated. Due to profound hypokalemia (up to 1.9 mmol/l), spironolactone 300 mg/day + kalium chloride 1200 mg were added to therapy. In view of newly diagnosed diabetes due to hypercortisolism, insulin therapy was initiated according. In November 2022 left-side adrenalectomy was performed with preliminary preparation of the α-adrenergic blocker doxazosin with dose escalation to 4 mg/day. Morphological examination revealed pheochromocytoma; immunohistochemistry verified intense expression of chromogranin A and ACTH by pheochromocytoma cells.

Conclusion: Considering the rarity of the described pathology, correct diagnostic tactics make it possible to reliably establish a diagnosis and provide timely medical care before the development of life-threatening cortisol- and adrenaline-mediated complications.