Dayanand Medical College and Hospital Ludhiana, Punjab, India
Saumya Ahluwalia, MBBS, Srishti Ahluwalia, MBBS, Ramit Mahajan, MBBS, MD, DM, Aminder Singh, MBBS, MD Dayanand Medical College and Hospital, Ludhiana, Punjab, India
Introduction: Schwannomas are rare spindle cell tumors originating from peripheral nerve Schwann cells and classified under Gastrointestinal autonomic nerve tumors (GANTs). The common sites of gastrointestinal (GI) schwannomas are stomach (83%), small bowel (12%), colon and rectum (3%). A majority of GI schwannomas are diagnosed incidentally during endoscopy or abdominal imaging. Though benign, they have a potential to turn malignant; hence they usually require surgical resection. We report the case of a transverse colonic schwannoma presenting as colo-colonic intussusception, which was managed by endoscopic removal.
Case Description/Methods: A 47-year-old female patient presented with recurrent, crampy upper abdominal pain and 5 kg weight loss for three months. Clinical examination was unremarkable and laboratory workup revealed normal hemoglobin (12.2 g/dL), normal inflammatory markers (ESR 24 mm/h, CRP 3.2 mg/dL) and CEA of 2.26 ng/mL. Computed tomography (CT) enterography revealed a colo-colonic intussusception with a polypoid lesion at the lead point without any evidence of proximal obstruction (Figure A-C). Colonoscopy revealed a single 3.5 cm x 3 cm pedunculated polyp in the transverse colon. An endoloop was deployed around the thick pedicle and snare polypectomy was done above the closed endoloop (Figure D-F) . There was no post procedure complication. Histopathological examination revealed a cellular tumor in submucosa with cells arranged in sheets and fascicles. Immunohistochemistry revealed positivity for vimentin and intact H3K27ME3 nuclear positivity in tumor cells indicating benign nature of this neural tumor (Figure G-I). She improved clinically with resolution of pain and a repeat colonoscopy done after 6 months was normal.
Discussion: Colorectal schwannomas account for only 3% of GANT. To the best of our knowledge, only 6 transverse colonic tumors have been reported in medical literature. They are difficult to diagnose preoperatively; being asymptomatic and discovered on screening endoscopy or cross-sectional imaging. Endoscopically, these lesions are usually submucosal. Therefore, biopsies from overlying mucosa are usually inconclusive. Very often, diagnosis is confirmed on surgically resected specimens. Our patient presented at a relatively younger age with intermittent colo-colonic intussusception caused by the pedunculated polyp and managed by endoloop-assisted polypectomy. Her symptoms resolved and follow-up colonoscopy at 6 months was normal.
Figure: CECT abdomen axial sections figure (A) and (B); coronal section figure (C) showing telescoping of distal loop of transverse colon into splenic flexure (blue arrow) with a heterogeneously enhancing polypoid lesion as its lead point (yellow arrow). Colonoscopy figure (D) shows a large pedunculated polyp ‘P’ in the transverse colon; figure (E) an endoloop ‘L’ applied to the thick peduncle ‘S’ of the polyp; figure (F) endoscopically resected polyp Histopathology figure (G) shows tumor cells having spindled shaped wavy nuclei with tapering ends, ill-defined cytoplasm with focal nuclear atypia [hematoxylin–eosin (H&E) x400]. Immunohistochemistry figure (H) reveals cytoplasmic vimentin positivity of tumor cells and figure (I) intact H3K27ME3 nuclear positivity in tumor cells indicating benign nature of schwannoma.
Disclosures:
Saumya Ahluwalia indicated no relevant financial relationships.
Srishti Ahluwalia indicated no relevant financial relationships.
Ramit Mahajan indicated no relevant financial relationships.
Aminder Singh indicated no relevant financial relationships.
Saumya Ahluwalia, MBBS, Srishti Ahluwalia, MBBS, Ramit Mahajan, MBBS, MD, DM, Aminder Singh, MBBS, MD. P3812 - A Rare Cause of Colo-Colonic Intussusceptions: Colonic Schwannoma, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.
