Vanishing tumour of the colon ascendens due to acquired type II C1-inhibitor deficiency

Where we are with acquired angioedema due to C1 inhibitor deficiency: A systematic literature review

Acquired angioedema due to C1 inhibitor deficiency (C1-INH-AAE) is a rare disease characterized by adult-onset recurrent non-urticarial angioedema with low levels of C1-INH. It is associated with lymphoproliferative disorders, and treatments are off-label with variable success. We conducted a systematic literature review to include patients with C1-INH-AAE identified in PubMed and Embase databases between January 2006 and February 2021. Clinical features of these patients were summarized, and factors associated with disease remission were explored. A total of 121 patients were included in the current study with a median age at diagnosis of 64 years and 45.5% being male. An associated disease was recorded in 94 patients (77.7%), and lymphoproliferative disorder was the most reported (59/94, 62.8%). Anti-C1-INH autoantibodies were present in 45 of 71 patients (63.4%). Factors impacting disease remissions included age (odds ratio [OR] 0.951, 95% confidence interval [CI] 0.909-0.994, p = 0.027), male (OR 0.327, 95% CI 0.124-0.866, p = 0.025), presence of monoclonal gammopathy (OR 0.133, 95% CI 0.041-0.429, p = 0.001), requirement of specific on-demand treatment (OR 0.216, 95% CI 0.066-0.709, p = 0.012) and rituximab use (OR 2.865, 95% CI 1.038-7.911, p = 0.042). A total of nine patients (7.4%) died at last follow up and most were unrelated to C1-INH-AAE. Our results imply that C1-INH-AAE is primarily associated with underlying B or plasma cell abnormalities, and clone-directed therapies could be promising options for its long-term management.

Multiple non-polypoid mucosal Schwann cell hamartomas presenting as edematous and submucosal tumor-like lesions: a case report

Background

Mucosal Schwann cell hamartomas are rare neurogenic tumors which present most commonly in the distal colon. They are usually discovered as small, single polyps in asymptomatic patients.

Case presentation

An asymptomatic 64-year-old man was referred to us after a 12 mm subepithelial lesion was discovered incidentally on screening colonoscopy. Follow-up colonoscopy conducted 2 months later revealed that the tumor had disappeared, leaving multiple edematous, submucosal tumor-like elevations presenting as skip lesions throughout the sigmoid colon. Lesions had elongated pits on magnifying endoscopy and were limited to the first layer on endoscopic ultrasound. Biopsies revealed unclearly delineated foci of spindle-shaped cells limited to the lamina propria. On immunohistochemistry, all lesions were positive for S-100 protein and negative for CD34, CD56, and neurofilament protein. The patient was diagnosed with multiple mucosal Schwann cell hamartomas of the sigmoid colon. He remains asymptomatic after 18 months of follow-up, but the lesions have also remained unchanged.

Conclusion

We report a case of multiple non-polypoid mucosal Schwann cell hamartomas. Endoscopic findings may assist in the differential diagnosis, particularly when presenting as non-polypoid, submucosal tumor-like lesions.