Clinical Case Summary

Introduction: Cap polyposis is a rare benign inflammatory condition characterized by inflammatory polyps covered with a fibrinopurulent exudate. It is more commonly observed in women and the elderly, although it can present at any age. The disease typically affects the rectum and sigmoid colon. The most frequent symptoms include mucous diarrhea and rectal bleeding. It has been associated with mucosal prolapse due to altered intestinal motility, Helicobacter pylori infection, and even intestinal dysbiosis.
Endoscopy: A 46-year-old male with no relevant personal or family medical history presented with altered bowel habits, characterized by increased stool frequency, decreased consistency, and the presence of mucus and blood, along with tenesmus and urgency. H. pylori testing was negative. Colonoscopy revealed numerous sessile and pedunculated polyps with an inflammatory appearance distributed throughout the colon, predominantly in the sigmoid and rectum. Most polyps were covered at their apex by a fibrinopurulent exudate (Figures 1–4). The colonic mucosa adjacent to the polyps appeared normal. Multiple biopsies were taken, confirming inflammatory polyps. A first therapeutic colonoscopy was performed, during which multiple polyps consistent with cap polyps were resected (Figure 5). Additional sessions were scheduled to complete polyp resection. Furthermore, a molecular study was performed using next-generation sequencing (NGS) with a multigene panel including genes associated with polyposis, with negative results.
Conclusions: The clinical course of cap polyposis remains unclear. The need for and timing of colonoscopy should be individualized based on the number of polyps and symptom severity. Initial treatment should be conservative, focusing on resolving constipation and eradicating H. pylori. In cases with persistent symptoms, endoscopic resection of the lesions should be considered.

Clinical Case Summary

Duodenal-Type Follicular Lymphoma (DTFL) is a rare form of non-Hodgkin’s lymphoma, accounting for <4% of gastrointestinal lymphomas. Though generally indolent, misdiagnosis can lead to delayed diagnosis in progressive cases. We present a case highlighting the importance of awareness for early detection. A 53-year-old woman with persistent epigastralgia underwent esophagogastroduodenoscopy (EGD) three times over five years at different hospitals. Only the latest EGD revealed multiple whitish nodular lesions in the first portion of the duodenum. Biopsies showed follicular proliferation confined to the mucosa, composed of small cleaved lymphoid cells. Immunohistochemistry confirmed a B-cell phenotype (CD20+, CD79a+, CD3-, CD5-), a germinal center phenotype (CD10+, Bcl6+), Bcl2 expression and low Ki-67. Blood tests were unremarkable, and viral serology was negative. CT scans revealed only reactive submandibular lymph nodes, with a normal bone marrow biopsy. PET scan showed uptake limited to the duodenum, confirming stage I disease (Lugano classification). Given its indolent course, a watch-and-wait strategy was adopted, with stable findings at a six-month follow-up EGD. DTFL is often incidentally detected during endoscopy and can be mistaken for benign conditions. Although typically localized, it may spread beyond the duodenum. Awareness is crucial to avoid unnecessary interventions and ensure timely diagnosis. Immunohistochemistry is key to distinguishing DTFL from reactive lymphoid hyperplasia and other low-grade lymphomas. While treatment options vary, active surveillance remains the most common approach due to its favorable prognosis. This case highlights DTFL as a rare but clinically significant entity that is frequently misdiagnosed, leading to unnecessary procedures. Recognizing its endoscopic and histologic features is essential for early diagnosis and appropriate management.

References

Figure 1: Upper endoscopy shows nodularity with whitish spots in the second portion of the duodenum (D2)
Figure 2: Endoscopic view showing a whitish polypoid lesion approximately 3 cm from the papilla
Figure 3: Duodenal mucosa with nodular lymphoid infiltrate, suggestive of duodenal-type follicular lymphoma

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