S4006 Trust Your Gut: Unexpected Colonic Mucosal Schwann Cell Hamartomas in a Young Adult

Introduction: Mucosal Schwann cell hamartoma (MSCH) is a rare, benign neural lesion of the gastrointestinal tract, first described in 2009. Fewer than 90 cases have been reported. MSCHs are typically asymptomatic and identified incidentally during routine colorectal cancer screening. This case presents an unusual finding in a young patient, highlighting the importance of histological evaluation for accurate diagnosis. Case Description/Methods: A 36-year-old woman presented with persistent constipation and requested a colonoscopy for evaluation. Colonoscopy revealed 6 polyps, 4 of which were diagnosed as MSCHs by spindle cell proliferation in the lamina propria with diffuse S-100 positivity. Two polyps were removed by cold snare and 4 by cold biopsy forceps. The patient denied a family history of colorectal cancer but reported her mother’s death from sepsis linked to gastrointestinal issues. Despite being younger than typical MSCH patients, she was managed conservatively with medical therapy and advised routine surveillance in 5 years. Discussion: MSCH is generally benign and asymptomatic, but its spindle cell morphology can resemble other lesions such as gastrointestinal stromal tumors or neurofibromas. Accurate histopathologic and immunohistochemical analysis is crucial to distinguish MSCH from concerning pathologies. This case highlights the importance of patient advocacy, as the patient’s proactive approach led to an early, incidental diagnosis. The presence of 6 MSCH polyps is also noteworthy, as multifocal presentations are rare and contribute valuable data to the limited literature on MSCH. This case illustrates a rare presentation of MSCH in a young patient, emphasizing the importance of listening to patient concerns. Despite its benign nature, MSCH can be mistaken for more ominous lesions, highlighting the essential role of histopathology. The patient’s proactive approach and subsequent diagnosis underscore the significance of patient-centered care and early detection in managing rare, often asymptomatic conditions.