Fibrous Obliteration of the Appendix Mimicking Acute Appendicitis: A Case Report
DOI:
https://doi.org/10.51168/7yqnxp22Keywords:
Appendiceal neuroma, Appendicitis, Fibrous obliteration, Neurogenic appendicopathy, Neurogenic hyperplasia, S-100 immunostainingAbstract
Background:
Fibrous obliteration of the appendix, also termed appendiceal neuroma, neurogenic appendicopathy, or neurogenic hyperplasia, is an uncommon benign lesion characterized by replacement of the appendiceal lumen by spindle-cell proliferation, fibrosis, and neural-type tissue. It is usually detected incidentally in appendicectomy specimens but may clinically and radiologically mimic acute appendicitis. The objective of this case report is to describe a rare case of fibrous obliteration of the appendix presenting as suspected acute appendicitis and to highlight the diagnostic value of histopathology and immunohistochemistry.
Case presentation:
A 40-year-old man presented with severe right lower quadrant abdominal pain for three days, localized right iliac fossa tenderness, rebound tenderness, mild fever, and neutrophilic leukocytosis. Ultrasonography suggested an inflamed appendix, while computed tomography showed a complex, thick-walled collection with air foci inferior to the caecum and periappendicular inflammatory changes, raising suspicion of appendicular abscess. Laparoscopic appendicectomy was performed. Gross examination revealed a grey-white appendix measuring 3.5 × 1.2 × 1 cm with congested vessels and an obliterated grey-white lumen. Microscopy showed luminal obliteration by spindle cells with wavy nuclei arranged in bundles, associated fibrosis, and inflammatory infiltrate predominantly composed of lymphocytes and eosinophils. S-100 immunostaining was positive in the spindle cells, confirming appendiceal neuroma/fibrous obliteration.
Conclusion:
Fibrous obliteration of the appendix is a rare benign lesion that can closely simulate acute appendicitis. Routine histopathological examination of appendicectomy specimens, supported by S-100 immunostaining when required, is essential for definitive diagnosis and exclusion of other appendiceal stromal or neurogenic lesions.
Take-away lessons:
Clinicians and pathologists should consider fibrous obliteration in appendicitis-like presentations with an obliterated lumen. Histopathology remains decisive, and immunohistochemistry helps avoid misclassification of this benign entity.
References
Jagtap SV, Boral S, Jagtap SS, Ajagekar PD. Appendiceal neuroma: an uncommon entity. Int Surg J. 2019;6(7):2631-2633.
2. Stanley MW, Cherwitz D, Hagen K, Snover DC. Neuromas of the appendix. A light-microscopic, immunohistochemical and electron-microscopic study of 20 cases. Am J Surg Pathol. 1986;10(11):801-815.
3. Choi SJ, Jang YJ, Lee D, Cho SH, Kim GC, Bae JH, et al. Two cases of fibrous obliteration of the appendix, mimicking acute appendicitis. J Korean Soc Radiol. 2014;70(6):430-434.
4. Masson P. Carcinoids (argentaffin-cell tumors) and nerve hyperplasia of the appendicular mucosa. Am J Pathol. 1928;4:181-211.
5. Vyas Y, Khattri J, Sanwalka M, Aswani P. Fibrous obliteration of appendix: a mimicker of appendicitis-case series. Int J Sci Res. 2020;9:30-32.
6. Greenson JK, Lauwers GY, Montgomery EA, Owens SR, Polydorides AD, Srivastava A, et al. Diagnostic Pathology: Gastrointestinal. Elsevier; 2016. p. 310-311.
7. Molina GA, Torres MA, Montenegro MS, Sanchez GD, Arcia AC, Enriquez JJ, et al. Neuroma of the appendix, a rare cause of appendicitis and an important reason for close follow-up. J Surg Case Rep. 2020;(3).
8. Rhoades T, Lohr J, Jennings M. Symptoms of acute appendicitis caused by primary neuroma of the appendix. Am Surg. 2007;73:841.
9. Sesia SB, Mayr J, Bruder E, Haecker FM. Neurogenic appendicopathy: clinical, macroscopic, and histopathological presentation in pediatric patients. Eur J Pediatr Surg. 2013;23(03):238-242.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Dr P. Sandya Rani Guruvelli, Dr Sravanthi Gurugubelli, Dr Vattikuti Satya Veni, Dr Kaki Hari Priya, Dr Atla Bhagya Lakshmi (Author)
This work is licensed under a Creative Commons Attribution 4.0 International License.
