Ki-67 and Tumor Size in Small Bowel Tumors: Findings from an Exploratory Immunohistochemical Analysis
Laurențiu Augustus Barbu1, Liliana Cercelaru2, Valeriu Șurlin3
1Department of Surgery, Railway Clinical Hospital Craiova, University of Medicine and Pharmacy of Craiova, 200349 Craiova, Romania.
Background:
Small bowel tumors are rare and biologically diverse, and prognostic assessment remains difficult, particularly regarding proliferative markers such as Ki-67 and tumor size.
Objective:
To evaluate the clinicopathological and immunohistochemical characteristics of small bowel tumors and explore factors associated with malignancy.
Methods:
A retrospective analysis of 61 surgically treated primary small bowel tumors (2020-2024) was performed using WHO 2019/2022 and AJCC 8th criteria. Immunohistochemistry included CD117, DOG1, CD34, SMA, and Ki-67.
Results:
Adenocarcinomas were most frequent (52.5%), followed by GISTs (26.2%) and NETs (9.8%). CD117 and DOG1 were expressed in 93.8% of GISTs, confirming high diagnostic specificity. The median Ki-67 index was 8%, significantly higher in non-GIST tumors (p = 0.004). Tumor size correlated moderately with Ki-67 (ρ = 0.42, p = 0.018). In this exploratory model, tumor size > 5 cm (p = 0.03) and Ki-67 > 10% (p = 0.04) were associated with malignancy.
Conclusions:
Tumor size and Ki-67 were associated with malignancy in this exploratory multivariable analysis, but these findings should be interpreted with caution due to limited follow-up and sample imbalance. Combined with CD117/DOG1 profiling, they enhance diagnostic accuracy and may inform diagnostic assessment; however, prognostic implications require outcome-based studies.
