Increased chromogranin a and carcinoid syndrome-like symptoms in a patient treated with duloxetine.

OBJECTIVE

We report the case of a 50-year-old female patient who presented with symptoms suggestive of a serotonin-secreting neuroendocrine neoplasm. In addition, her serum chromogranin A (CA) level was elevated by more than 8-fold.

METHODS

We present a case report with review of the relevant literature.

RESULTS

No abnormalities could be detected in a complete conventional and functional morphological diagnostic work-up including a gallium-68-DOTA-d-Phe1-Tyr3-octreotide (Ga-68-DOTATOC) positron emission tomography-computed tomography (PET-CT) scan. These negative results prompted us to consider possible drug-related effects as the cause for these findings. The patient had started to take duloxetine, a second-generation antidepressant (SGA) and selective serotonin-norepinephrine reuptake inhibitor (SNRI), at a dose of 60 mg/day 2 months prior to her first visit at our department for pain relief. After withdrawal of duloxetine, her symptoms promptly ceased, and her CA levels fell to normal values within 7 weeks.

CONCLUSION

We conclude that selective serotonin-norepinephrine reuptake inhibitors (SNRIs) can cause symptoms suggestive of serotonin-secreting neuroendocrine neoplasms, as well as elevated CA levels leading to unnecessary and expensive diagnostic workups. To our knowledge, the association between SNRI treatment and increased CA levels has not been described in the literature and needs to be further evaluated in well-controlled prospective studies.