Prospective evaluation of common hepatic duct histopathology at the time of choledochal cyst excision ranging from children to adults

Purpose: To evaluate common hepatic duct just distal to the HE anastomosis (d-CHD) prospectively for mucosal damage, inflammation, fibrosis, dysplasia, carcinoma in situ, malignant transformation, effects of serum amylase, and symptoms at presentation in CC cases ranging from children to adults.

Methods: Cross-sections of d-CHD obtained at cyst excision 2018-2023 from 65 CC patients; 40 children (< 15 years old), 25 adults (≥ 15) were examined with hematoxylin and eosin, Ki-67, S100P, IMP3, p53, and Masson's trichrome to determine an inflammation score (IS), fibrosis score (FS), and damaged mucosa rate (DMR; damaged mucosa expressed as a percentage of the internal circumference).

Results: Mean age at cyst excision ("age") was 18.2 years (range: 3 months-74 years). Significant inverse correlations were found for age and DMR (p = 0.002), age and IS (p = 0.011), and age and Ki-67 (p = 0.01). FS did not correlate with age (p = 0.32) despite significantly increased IS in children. Dysplasia was identified in a 4-month-old girl with cystic CC. Serum amylase was elevated in high DMR subjects.

Conclusions: High DMR, high IS, and evidence of dysplasia in pediatric CC suggest children are at risk for serious sequelae best managed by precise histopathology, protocolized follow-up, and awareness that premalignant histopathology can arise in infancy.