PT - JOURNAL ARTICLE AU - Navale, Pooja AU - Glickman, Jonathan AU - Nasser, Imad AU - Shia, Jinru AU - Vyas, Monika TI - Ciliated foregut cysts involving the hepatopancreaticobiliary system: a clinicopathological evaluation with focus on atypical features AID - 10.1136/jcp-2023-208947 DP - 2024 Oct 01 TA - Journal of Clinical Pathology PG - 697--701 VI - 77 IP - 10 4099 - http://jcp.bmj.com/content/77/10/697.short 4100 - http://jcp.bmj.com/content/77/10/697.full SO - J Clin Pathol2024 Oct 01; 77 AB - Aims Foregut cystic malformations are rare developmental abnormalities, which may involve the hepatopancreaticobiliary tract (HPBT). These cysts are composed of inner ciliated epithelium; subepithelial connective tissue layer; smooth muscle layer; and an outer fibrous layer. While radiopathologic findings are often diagnostic, atypical location and histologic features can pose a diagnostic challenge. We aimed to study ciliated foregut cysts (CFCs) in the HPBT, assess their clinicopathological features with a focus on atypical features.Methods We collected cases of CFCs involving the HPBT from three large academic medical centres. H&E-stained slides and immunohistochemical stains (where available) were reviewed for each case. Relevant demographic, clinical and pathological information was collected from the medical records.Results 21 cases were identified. The median age was 53 years (range, 3–78 years). 17 cysts were identified within the liver (segment 4 was the most common location, n=10) and 4 in the pancreas. Cysts were mostly identified incidentally (n=13), abdominal pain was a common symptom (n=5). Cyst size ranged from 0.7 to 17.0 cm (median, 2.5 cm). Radiological findings were available in 17 cases. Cilia were identified in all cases. 19 of 21 cases demonstrated the presence of a smooth muscle layer (thickness, <0.1 mm to 3.0 mm). Three cases showed gastric metaplasia, while one case revealed additional low-grade dysplasia, with features similar to intraductal papillary neoplasm of the bile duct.Conclusions We highlight clinicopathological features of CFCs in the HPBT. The histomorphology is usually straightforward; however, unusual location and atypical features can pose a diagnostic challenge.All data relevant to the study are included in the article or uploaded as an online supplemental information.