Infectious pneumonia favored by paraneoplastic Cushing syndrome in a pulmonary carcinoid tumor

Introduction. - Ectopic Cushing's syndrome (CS) is a rare condition nevertheless well-known to endocrinologists. The pneumologist may be called upon to treat CS not only because bronchial carcinoid tumors are the most frequent source of ectopic ACTH secretion, but also due to the fact that the immunosuppression induced by hypercorticism favors lower respiratory tract infections. Case report. - We report the case of a female patient presenting with acute respiratory fai-lure secondary to Enterobacter cloacae pneumonia exacerbated by SC. Further investigations confirmed ectopic ACTH secretion and revealed a right upper lobe pulmonary nodule. After appropriate antibiotic therapy, the patient received preoperative adrenolytic treatment. Mana-gement by right upper lobectomy resulted in the extraction of a 12 mm tumor. Pathological analysis was consistent with the diagnosis of a typical carcinoid tumor. Immunohistochemis-try confirmed ACTH secretion by the tumor. Even though the postoperative course showed CS regression, the patient developed adrenal insufficiency. Conclusion. - Ectopic CS induces immunosuppression, which aggravates lower respiratory tract infections. Search for a pulmonary neuroendocrine tumor should be systematic. Following control of the secretory syndrome by adrenolytic treatment, and if the diagnosis of carcinoid tumor is confirmed, surgical treatment is the preferred option. (c) 2023 SPLF. Published by Elsevier Masson SAS. All rights reserved.