Reactive lymphoid hyperplasia of the appendix in children: a descriptive analysis of accompanying neural and stromal features

Background Reactive lymphoid hyperplasia (RLH) is frequently identified in pediatric appendectomy specimens performed for suspected acute appendicitis. However, its associated neural and stromal alterations remain incompletely characterized. Methods This retrospective descriptive study evaluated pediatric appendectomy specimens obtained between January 2019 and January 2024. RLH cases were identified based on histopathological criteria. Archived specimens were re-evaluated using hematoxylin and eosin staining, S-100 immunohistochemistry, and Masson's trichrome staining. Neural alterations were classified according to Höfler's criteria, and fibrosis was graded semiquantitatively. Results Among 468 appendectomies, 100 cases fulfilled the criteria for RLH. The mean age was 11.34 ± 4.31 years, and 63% were male. Neural and stromal alterations, including S-100–positive nerve elements and varying degrees of fibrosis, were frequently observed. Höfler Type 1 and Type 3 patterns were the most common, and fibrosis was predominantly mild to moderate. Postoperative symptom resolution was observed in patients with available follow-up. Conclusion RLH in children is commonly associated with reactive neural and stromal alterations. However, these findings should be interpreted as nonspecific reactive changes rather than disease-specific features. Further studies are needed to clarify their clinical significance.