Colonic Perineurioma Presenting as a Small Subepithelial Lesion With Distinctive Endoscopic Findings.
Colonic perineurioma should be considered in the differential diagnosis of small subepithelial lesions found during colonoscopy, with definitive diagnosis relying on histopathological evaluation.
Where it sits
this study against the rest of the glutathione (gsh) corpusSummary and findings
A 59-year-old man underwent a screening colonoscopy where a 5-mm reddish lesion was identified in the sigmoid colon. Cold snare polypectomy was performed, and histopathological examination revealed proliferation of bland spindle cells consistent with colonic perineurioma. Immunohistochemistry showed positivity for vimentin and GLUT-1, with a Ki-67 index of <1%.
Abstract
A 59-year-old man with a history of colorectal polypectomy underwent a screening colonoscopy. A 5-mm reddish lesion was identified in the sigmoid colon. The lesion had a smooth surface without erosion or ulceration and appeared slightly elevated with well-demarcated margins. Magnifying narrow-band imaging revealed dilated round pits, reduced crypt density, and arborizing vessels in the central area. Cold snare polypectomy was performed for diagnostic and therapeutic purposes. Histopathological examination demonstrated proliferation of bland spindle cells with oval nuclei in the lamina propria. Immunohistochemistry showed positivity for vimentin and GLUT-1, weak epithelial membrane antigen expression, and negativity for S-100, SMA, c-kit, and CD34, with a Ki-67 index of <1%. These findings were consistent with colonic perineurioma, a rare benign peripheral nerve sheath tumor composed of perineurial cells. This case highlights that colonic perineurioma should be considered in the differential diagnosis of small subepithelial lesions detected during colonoscopy. Reduced crypt density and arborizing vessels may provide subtle clues; however, definitive diagnosis requires histopathological and immunohistochemical evaluation.
Background
This paper addresses the identification and diagnosis of colonic perineurioma, a rare benign peripheral nerve sheath tumor. Prior knowledge indicates that such lesions can be challenging to diagnose during colonoscopy. The study emphasizes the importance of histopathological and immunohistochemical evaluation in confirming the diagnosis.
Methods
The study involved a 59-year-old male patient with a history of colorectal polypectomy who underwent a screening colonoscopy. A 5-mm lesion was identified, and cold snare polypectomy was performed for diagnostic and therapeutic purposes. Immunohistochemical analysis was conducted to evaluate the tumor's characteristics.
Results
The primary finding was a Ki-67 index of <1%, indicating low cellular proliferation. Histopathological examination revealed proliferation of bland spindle cells with oval nuclei in the lamina propria. The lesion exhibited positivity for vimentin and GLUT-1, with weak expression of epithelial membrane antigen.
Interpretation
The findings suggest that colonic perineurioma should be included in the differential diagnosis of small subepithelial lesions during colonoscopy. The low Ki-67 index indicates that the tumor is benign with low proliferation. However, the rarity of this condition and the reliance on histopathological confirmation limit the generalizability of these findings.
Key findings
- 5-mm reddish lesion identified in sigmoid colon.
- Ki-67 index of <1%.
- Histopathological examination demonstrated proliferation of bland spindle cells.
Limitations
- Single case report.
- No long-term follow-up reported.
- Not applicable for general population conclusions.