Relationship between Immunophenotype and Clinicopathological Findings for Superficial Nonampullary Duodenal Epithelial Tumor.

INTRODUCTION The natural history and prognosis of superficial nonampullary duodenal epithelial tumors (SNADETs) remain uncertain. We elucidated the relationship between immunophenotype and clinicopathological features. MATERIALS AND METHODS A total of 98 SNADETs were divided into 3 groups according to immunohistochemical findings: gastric phenotype (G type), gastrointestinal phenotype (GI type), and intestinal phenotype (I type). Cellular dysplasia was divided into low-grade dysplasia and high-grade dysplasia/adenocarcinoma (≥HGD). White opaque substance (WOS) deposition was categorized into diffuse WOS, partial WOS, and no WOS, based on endoscopic findings. RESULTS Of the 98 SNADETs, 4 lesions (4.1%) were G type, 32 lesions (32.7%) were GI type, and 62 lesions (63.2%) were I type. All G-type SNADETs were located in the oral side of the papilla including the bulb, and the rate of bulbar lesions was significantly higher in the G type than in the GI and I types (p = 0.004). The most frequent type of WOS was no WOS (4/4, 100%) for G type, partial WOS (19/32, 59.4%) for GI type, and diffuse WOS (34/62, 54.8%) for I type (p < 0.001), and loss of intestinal character was significantly correlated with WOS deficiency. GI/I-type SNADETs with partial or no WOS and G-type SNADETs were associated with ≥HGD. Additionally, the frequency of ≥HGD lesion was significantly higher in the CD10-negative group than in the CD10-positive group (57.1 vs. 19.8%, p = 0.043). CONCLUSION Pathological intestinal character was correlated with the presence of WOS, and CD10 loss was associated with malignant potential of SNADETs.