Endocrine Abstracts

Introduction: We describe the case of a 68-year-old patient, having two MEN1-associated tumors that are not part of the classical triad, with a penetrance of only 40%, and 2%, according to the medical literature. Furthermore, she developed a persistent hyperkalemia after the unilateral adrenalectomy, which is rare and often missed.

Case report: In 2011, following a non-specific symptomatology (dry cough, fatigue), a bilobectomy was performed (medium and right inferior lobes), the patient being diagnosed with typical pulmonary carcinoid, as stated by the histopathology and immunohistochemistry tests. 9 years later, in May 2020, the patient was admitted to the ER for cardiac tamponade, the neoplastic etiology being revealed by the histopathological examination. Afterwards, the outcome of the immunohistochemistry assessment was fibrino-hematic pericarditis, with mesothelial reaction, without tumor aspects. A December 2020 octreoscan scintigraphy detected pericardial and hepatic lesions, indicating pulmonary carcinoid metastases. Therefore, 1 month later, octreotide treatment was initiated (Sandostatin LAR 30 mg/month). In July 2021, the patient undertook another octreoscan scintigraphy showing only a new L4 lesion. In November 2021, the laboratory findings pointed to primary hyperaldosteronism with a high ARR (>84.2 ng/dl per uU/ml), undetectable renin with PAC>20 ng/dl (42.1 ng/dl), and hypokalemia (2.9 mmol/l). The most recent unenhanced thoracic-abdominal-pelvic CT scan identified a 22mm adenoma in the right adrenal gland, which had been registered in the patient’s medical records for 10 years. Due to endocrinological assessments which indicated subclinical hyperthyroidism, and a toxic multinodular goiter revealed by the thyroid scintigraphy, the Thyrozol treatment was restarted. In May 2022, the patient underwent right laparoscopic adrenalectomy. Gross pathologic examination revealed a 1.8 cm round, well-circumscribed nodule, while the microscopic examination confirmed the adrenal adenoma diagnosis. Pre-adrenalectomy, the patient’s renal function was impaired, with a 32.3mL/min/1.73 m² eGFR. The postoperative PAC declined to a low level: 13.1 ng/dl, while the serum potassium levels surged to 7.43mEq/l, and the eGFR further decreased to 17.5mL/min/1.73 m² with cortisol levels within the normal range. Subsequently, fludrocortisone 0.1 mg daily was initiated, and the patient’s potassium levels returned to the ULN (5.1 mmol/l) seven months after adrenalectomy.

Conclusion: Because of this rare phenotype association of primary hyperaldosteronism and pulmonary NET, the patient falls into both MEN1 and MEN4 syndrome. Close monitoring of postoperative potassium levels is crucial following adrenalectomy, especially those with altered renal function or advanced age, as they are at a higher risk of developing life-threatening hyperkalemia. Mineralocorticoid replacement therapy should be administered if necessary.