Ectopic adrenocorticotropic hormone syndrome in patients with olfactory neuroblastoma

Olfactory neuroblastomas rarely secrete adrenocorticotropic hormone, leading to ectopic adrenocorticotropic hormone syndrome. However, the prevalence, timing, and triggers of ectopic adrenocorticotropic hormone syndrome in patients with olfactory neuroblastomas remain unclear. This study aimed to investigate these factors and conduct a literature review. Fifteen patients with olfactory neuroblastomas who underwent surgery at our institution were included. The prevalence of ectopic adrenocorticotropic hormone syndrome development was assessed by evaluating adrenocorticotropic hormone expression using immunohistochemistry. Furthermore, 26 patients with olfactory neuroblastomas who developed ectopic adrenocorticotropic hormone syndrome from previous reports were reviewed. Among the 15 patients, three (20%) showed adrenocorticotropic hormone-positive tumor cells at the time of initial surgery, and two (13%) developed ectopic adrenocorticotropic hormone syndrome. The timing of developing ectopic adrenocorticotropic hormone syndrome was 2.5 and 10 years following the initial treatment of olfactory neuroblastoma. Based on the literature review, nine patients with recurrent and metastatic olfactory neuroblastoma developed ectopic adrenocorticotropic hormone syndrome after the initial surgery, of whom, three had confirmed disease after developing ectopic adrenocorticotropic hormone syndrome, three developed during disease progression, two developed after receiving chemotherapy, and one developed after undergoing a biopsy. The timing of ectopic adrenocorticotropic hormone syndrome was 2.5–15 years after initial treatment. Our study revealed that acknowledging olfactory neuroblastomas can manifest as ectopic adrenocorticotropic hormone syndrome with a certain low prevalence is crucial. Moreover, our study speculated that tumor stimulation, such as biopsy or chemotherapy, as well as disease progression, could trigger ectopic adrenocorticotropic hormone syndrome onset. Thus, olfactory neuroblastomas can develop into ectopic adrenocorticotropic hormone syndrome, even long after the initial treatment.