Cushing's syndrome due to ectopic adrenocorticotrophic hormone production by olfactory neuroblastoma.

OBJECTIVE

To review a case of olfactory neuroblastoma (ON) with Cushing's syndrome (CS) due to ectopic production of adrenocorticotrophic hormone (ACTH) and compare the histopathologic diagnosis, treatment modality, and prognostic factors with the literature.

METHODS

We report the clinical presentation, biochemistry, imaging, histopathology, treatment, and outcome of a patient with ON. We conducted an English language literature review of CS due to ectopic ACTH production and ON.

RESULTS

CS due to ectopic ACTH production is uncommon, and CS due to ON is extremely rare. A 19-year-old Hispanic man presented with right nasal obstruction, involuntary weight gain, and intensely pruritic skin rash. Examination revealed large, wide purple striae on both arms and the abdomen. Head magnetic resonance imaging (MRI) revealed a right ethmoid sinus enhancing mass extending into the orbit, nasal cavity, and maxillary and sphenoid sinuses. Laboratory results showed a pm cortisol level of 26 mcg/dL, a 24-hour urinary free cortisol level of 7,507 mcg, an ACTH level of 83 pg/mL, and nonsuppression of cortisol with an overnight dexamethasone suppression test (1 and 8 mg). A biopsy revealed ON, and immunohistochemistry (IHC) was positive for ACTH. He underwent chemotherapy followed by surgical debulking and adjuvant radiation therapy, with no disease recurrence through the last follow-up in February 2012. Plasma and urinary cortisol levels normalized following surgery.

CONCLUSION

This is the first case reported of a Hispanic male with an uncommon tumor (ON) and an even more uncommon presentation, ectopic ACTH production causing CS. The extremely high ACTH levels and plasma and urine cortisol levels dramatically dropped following multimodality management. So far, he has had 2.5 years of disease-free survival.