DOI: https://doi.org/10.36347/sjmcr.2026.v14i10.032

Pages: 2256-2259

Poorly cohesive carcinoma of the gallbladder is a very rare, often incidental finding. We present a 67-year-old woman with a clinical diagnosis of chronic calculous cholecystitis who underwent elective laparoscopic cholecystectomy. Histopathology revealed a poorly cohesive carcinoma with focal abortive glandular formation, arising in a background of biliary intraepithelial neoplasia (BilIN), ranging from low to high grade. The tumor infiltrated the serosa and perivesical adipose tissue, with lymphovascular and perineural invasion and a focally positive resection margin. According to AJCC 8th edition, the findings were pT3, pNx, pMx, L1, Pn1, G3, R1, with a conditional stage IIIA (if pN0, pM0). Immunohistochemistry showed mutant-type p53 expression, negative HER2, and PD-L1 TPS <1. Molecular analysis showed no activating KRAS/NRAS mutations (exons 2, 3, 4), no BRAF p.V600E/K mutation, and no microsatellite instability. The patient was suitable for adjuvant oncological therapy and died approximately 20 months after the histopathological diagnosis, a longer survival than in several of the reported cases. We also review similar cases from the literature.