Rectal Paraganglioma Presenting as a Diminutive Polyp

CASE REPORT A 46-year-old man presented to our clinic for a colonoscopy due to nonbloody diarrhea lasting about 1 year. His medical history revealed only arterial hypertension treated with angiotensin-converting enzyme inhibitor therapy. The examination showed normal ileal and colonic mucosa. In the rectum, a diminutive polyp of 4 mm was found and removed with cold snare. Images of the polyp under white light and narrow-band imaging are provided (Figure 1). The pathological findings revealed the presence of paraganglioma. The polyp was positive for chromogranin and synaptophysin (Figure 2).Figure 1.: Colonoscopy images showing polyp under white light (A) and narrow-band imaging (B).Figure 2.: Histological features of the lesion showing immunoreactivity chromogranin (A) and synaptophysin (B).A total-body computed tomography scan and magnetic resonance imaging of the abdomen were performed, revealing no sign of metastasis. A colonoscopy was repeated after 9 months, resulting normal. The patient is still under follow-up at our department. Paragangliomas are rare nonepithelial neuroendocrine tumors that typically develop in the extra-adrenal sites along the sympathetic and/or the parasympathetic chain. Their location in the gastrointestinal tract is quite rare. In literature, there are only few cases regarding the colon and rectum and only of large and metastatic lesions.1–5 To the best of our knowledge, we present the first case of a rectal paraganglioma reported as a diminutive polyp. DISCLOSURES Author contributions: L. De Luca, F. Martinovic, M. Arena, DL Milena, and I. Giuseppe wrote this article, and L. De Luca critically reviewed it. Z. Moreno provided the histological images of the polyp. All the authors approve this draft. L. De Luca is the article guarantor. Financial disclosure: None to report. Informed consent was obtained for this case report.