Pregnancy-induced Cushing's syndrome with an adrenocortical adenoma overexpressing LH/hCG receptors: a case report.

Background: Pregnancy-induced Cushing's syndrome (CS) with an adrenocortical adenoma overexpressing luteinizing hormone (LH)/human choriogonadotropin (hCG) receptors (LHCGR) has been rarely reported in the literatures. This peculiar condition challenges the canonical diagnosis and management of CS.

Case Presentation: A 27-year-old woman (G2P0A1) presented at 20 weeks gestational age (GA) with overt Cushingoid clinical features. Adrenocorticotropic hormone (ACTH)-independent CS was diagnosed based on undetectable ACTH and unsuppressed cortisol levels by dexamethasone. Magnetic resonance imaging (MRI) scanning without contrast revealed a left adrenal nodule while pituitary MRI scanning was normal. A conservative treatment strategy of controlling Cushingoid comorbidities was conducted. At 36 weeks GA, a caesarean operation was performed and a live female infant was delivered. At 8 weeks after parturition, our patient achieved normalization of blood pressure, blood glucose, serum potassium, and urinary cortisol level spontaneously. During non-pregnancy period, stimulation testing with exogenous hCG significantly evoked a cortisol increase. The woman underwent resection of the adrenal tumor at 6 months after parturition. Immunohistochemistry (IHC) showed the tumor tissue that stained positive for luteinizing hormone (LH)/human choriogonadotropin (hCG) receptor (LHCGR), whereas negative for both melanocortin 2 receptor (MC2R) and G protein-coupled receptor-1 (GPER-1).

Conclusions: Stimulation test with exogenous hCG after parturition is necessary for the diagnosis of pregnancy-induced CS. LHCGR plays an essential role in the pathogenesis of this rare condition.