Endocrine Abstracts

Case description: A 32-year-old male patient was treated with remdesivir and high-dose steroid for severe COVID-19 pneumonia in an ICU for one month. He was later diagnosed with steroid-induced diabetes mellitus. An endocrinological consultation raised the possibility of endogenous Cushing’s syndrome. He was then referred to our department for further investigation of suspected Cushing’s syndrome (CS). The patient presented with typical physical signs and symptoms of CS. Severe ACTH-dependent hypercortisolism was diagnosed. The high dose dexamethasone test, the marked ACTH response to iv. desmopressin and a pituitary microadenoma revealed by MRI suggested Cushing’s disease. However, chest CT showed a 1 cm mass compatible with a pulmonary NET in the left S7. In the first phase of investigations, the origin of the ACTH-dependent CS was equivocal. All of the non-invasive tests argued for the pituitary source of ACTH excess. Because of the high radiological suspicion of pulmonary NET, and despite the results of the traditional hormone tests, both our pituitary and pulmonary boards suggested pulmonary surgery as a first-line intervention. Thus, a segmentectomy was performed; histology confirmed a typical bronchial carcinoid with intense ACTH expression. Postoperatively, persisting hypercortisolism was proved, necessitating an inferior petrosal sinus sampling (IPSS). IPSS excluded CD and unambiguously confirmed the ectopic nature of ACTH secretion. Unfortunately, all the postoperative imaging modalities, including ¹⁸FDG-PET-CT and Tc-99m-Tektrotyd SPECT/CT, were negative, suggesting an occult residual metastatic tumour. ⁶⁸Ga-DOTATOC-PET-CT was suggested; however, the patient could not afford it. Metyrapone, followed by osilodrostate, was started. Severe resistant hypercortisolism persisted, leading to pathological vertebral compression fractures, despite 6 months of treatment with osilodrostate in a daily doses of up to 2x15 mg. However, no metastatic lesion could be identified. We decided to perform a bilateral total adrenalectomy, which resulted in a prompt resolution of hypercortisolism. The localization of suspected metastatic tumour(s) is still uncovered.