A 50-year-old woman presents with recurrent episodes of watery diarrhea, flushing, and wheezing for the past year. She also mentions episodes of rapid heartbeat. Lab tests show elevated levels of serotonin in her blood. What could be the potential causes?
This patient's symptoms and lab findings suggest carcinoid syndrome, which occurs when a carcinoid tumor (a type of neuroendocrine tumor) secretes large amounts of serotonin. This syndrome typically presents with flushing, diarrhea, and wheezing. This diagnosis can be further confirmed by measuring 24-hour urinary 5-HIAA (5-Hydroxyindoleacetic Acid), a metabolite of serotonin. If confirmed, further imaging studies like CT or MRI can help locate the tumor.