Ectopic ACTH production by thymic and appendiceal neuroendocrine tumors - two case reports.

Background Ectopic adrenocorticotropic syndrome (EAS) causes approximately 10-18% of cases of Cushing's syndrome (CS) in adults, while in children it occurs much less frequently. What is new? We present a long-term follow-up (8 and 13 years) of the only two cases of rare neuroendocrine tumors in 30 years of a single center experience, which is unique in the literature concerning the pediatric population. Case presentation We report two cases of neuroendocrine tumors (of the thymus and the appendix) in a 12-year-old boy and a 15-year-old girl who presented with the clinical features of CS. Elevated serum cortisol, ACTH, and chromogranin levels were observed in both patients. Diagnoses were made on the basis of a mass in the thymus/appendix region visualized with chest/abdominal CT scan and radiotracer accumulation in scintigraphy in the same areas. Histopathological examinations confirmed the diagnoses of NET. Conclusion EAS is an extremely rare endocrine disorder. However, it should be taken into consideration in the diagnostic process of every case of ACTH-dependent CS.