AN ANALYSIS OF PATHOLOGIC FEATURES IN SURGICALLY RESECTED ADULT CHOLEDOCHAL CYSTS: ARE THERE CLINICAL SUBTYPES?
Aradhya Nigam*, Salima Mansoor Ali, Grace C. Bloomfield, Maryam Boumezrag, DongHyang Kwon, Reena jha, Jason Hawksworth, Thomas Fishbein, Pejman Radkani, Emily Winslow
Georgetown University Medical Center, Washington,
Introduction
The pathogenesis of choledochal cysts remains largely unestablished. Recent data from a single Korean series demonstrated smooth muscle patterns to be associated with chronic inflammation and clinical outcomes in patients who underwent resection. However, smooth muscles patterns have not yet been investigated in other populations with choledochal cysts. We aimed to characterize smooth muscle patterns amongst adult patients who underwent surgical resection for choledochal cysts and examine their surgical outcomes.
Methods:
A multi-institutional, retrospective analysis was conducted of patients who underwent choledochal cyst resection between 1998-2021. Patients with available post-surgical specimens were pathologically re-reviewed and categorized into smooth muscle pattern groups: absent, scattered, and interrupted/continuous. Preoperative imaging characteristics, extent of histologic inflammation, and disease-specific outcomes were evaluated and compared relative to smooth muscle patterns. Statistical significance was set at a threshold of p<0.05.
Results:
Of the total cohort of 121 patients with resected choledochal cysts, 79 patients had pathologically evaluable specimens. Median follow-up was 34 months (IQR 14-66). Median age at diagnosis was 60 years (IQR 45-67) with 80% of patients being female and 89% having a Todani type I choledochal cyst. Sixty-two (79%) patients presented with symptoms while 15 (19%) patients were incidentally found and 2 patients with unknown symptoms. On careful pathologic evaluation, no inflammation was identified in 36 (45%), mild in 33 (42%), and moderate/severe in 10 (13%) patients; 18 (23%) patients demonstrated ulceration. When categorized by smooth muscle pattern in the cyst wall, 19 (24%) had absent, 39 (49%) had scattered, and 21 (27%) had continuous/interrupted smooth muscle patterns (Table 1). Interestingly, a significantly greater proportion of continuous/interrupted pattern patients were identified to have an anomalous pancreatobiliary junction (71% continuous/interrupted, 40% scattered, 33% absent; p<0.01). Other pathologic characteristics including proportion of patients with mod/severe inflammation (p=0.38), denudation (p=0.37), ulceration (p=0.09), and premalignant (0.98) and malignant (0.88) lesions were similar. In addition, outcomes including development of a biliary complication (p=0.89) and disease-specific death (0.99) did not differ amongst groups.
Conclusion:
This study demonstrates that adults in the US with choledochal cysts can be subtyped by the cyst wall muscle pattern. The difference in rates of anomalous PBJ amongst subtypes suggests that multiple mechanisms may contribute to the pathogenesis of choledochal cysts. Additional work is needed to assess the impact of biliary smooth muscle patterns on disease pathogenesis and outcomes.
Back to 2023 Abstracts