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World J Gastroenterol. Jul 7, 2026; 32(25): 116783
Published online Jul 7, 2026. doi: 10.3748/wjg.116783
Published online Jul 7, 2026. doi: 10.3748/wjg.116783
Abdominal nodular histiocytic/mesothelial hyperplasia - intraoperative pitfalls, differential diagnosis, literature review: A case report
Piergiuseppe Colombo, Carlo Castoro, Department of Biomedical Science, Humanitas University, Pieve Emanuele, Milan, Italy
Piergiuseppe Colombo, Paola Spaggiari, Department of Pathology, IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
Giulia Dani, Benedetta Saracini, Humanitas University, Pieve Emanuele, Milan, Italy
Carlo Castoro, Department of Upper Gastrointestinal Surgery, IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy
Author contributions: Colombo P was involved in the conceptualization, revising histological specimen, interpretation of immunohistochemical results, writing and revision of the final manuscript; Dani G and Saracini B were involved in literature retrieval, writing the manuscript, and immunohistochemical results interpretation; Castoro C was involved in management of patient, providing clinical data and follow up; Spaggiari P selected histological slides for immunohistochemistry, and critically revised the final manuscript; and all authors have read and approved the final manuscript.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Corresponding author: Piergiuseppe Colombo, Associate Professor, Department of Biomedical Science, Humanitas University, Via Rita Levi Montalcini, 4, Pieve Emanuele, Milan, Italy. piergiuseppe.colombo@hunimed.eu
Received: November 21, 2025
Revised: January 9, 2026
Accepted: March 26, 2026
Published online: July 7, 2026
Processing time: 222 Days and 2.5 Hours
Revised: January 9, 2026
Accepted: March 26, 2026
Published online: July 7, 2026
Processing time: 222 Days and 2.5 Hours
Core Tip
Core Tip: Nodular histiocytic/mesothelial hyperplasia is a rare benign lesion that may mimic peritoneal dissemination of malignancy, especially during frozen-section examination. This case emphasizes the diagnostic pitfalls arising from its histologic resemblance to metastatic carcinoma and highlights how coexistence with true metastatic implants increases the risk of misinterpretation. Few reports describe concurrent metastatic carcinoma and nodular histiocytic/mesothelial hyperplasia, making intraoperative differentiation particularly challenging. Knowledge of its characteristic morphology and immunoprofile is crucial for surgeons and pathologists.