Hindawi Publishing Corporation Case Reports in Medicine Volume 2009, Article ID 457975, 4 pages doi:10.1155/2009/457975 Case Report Nodular Regenerative Hyperplasia Secondary to Neoadjuvant Chemotherapy for Colorectal Liver Metastases Maartje A. J. van den Broek,1 Steven W. M. Olde Damink,1 Ann Driessen,2 Cornelis H. C. Dejong,1 and Marc H. A. Bemelmans1 1 Department of Surgery, Maastricht University Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands 2 Department of Pathology, Maastricht University Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands Correspondence should be addressed to Marc H. A. Bemelmans, m.bemelmans@mumc.nl Received 15 July 2009; Accepted 6 October 2009 Recommended by Elijah Dixon Liver resection is the only curative treatment for patients with colorectal liver metastases (CLMs). Neoadjuvant chemotherapy can improve resectability but has a potential harmful eﬀect on the nontumorous liver. Patients with chemotherapy-induced hepatic injury undergoing liver surgery have higher risks of post-resectional morbidity. We present two cases of patients without pre- existent liver disease treated with oxaliplatin-based chemotherapy followed by surgical resection of their CLMs. Their intra- operative liver specimen showed morphologic abnormalities characteristic of nodular regenerative hyperplasia (NRH). NRH led to portal hypertension in both patients that resulted in deleterious post-resectional complications and death of one patient. Interestingly, the other patient underwent two repeat nonanatomic liver resections because of recurrent CLMs. The intra-operative liver specimen still showed signs of NRH and sinusoidal congestion, but the post-resectional courses were uneventful. Nevertheless, caution is recommended in patients with suspected NRH. Careful volumetric analysis should guide the operative strategy. When future remnant liver volume is regarded insuﬃcient, portal vein embolization or restrictive surgery should be considered. Copyright © 2009 Maartje A. J. van den Broek et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. Introduction Colorectal liver metastases (CLMs) develop in 50–60% of patients with colorectal carcinoma. Resection remains the only curative treatment, but just 15–20% of patients are initially eligible for resection. Administration of neoadju- vant chemotherapy can improve resectability in 15–30% of patients with initially unresectable disease [1]. In addition, perioperative chemotherapy has also been proven to elongate progression-free survival in patients with initially resectable disease [2]. However, recent reports show a potential harm- ful eﬀect of oxaliplatin or irinotecan-based neoadjuvant chemotherapy on the nontumorous liver [3–5]. Patients with histologically proven chemotherapy-related hepatic injury undergoing liver surgery have higher risks of post-resectional morbidity [6] and mortality [5]. Here, we present two cases of patients without pre- existent liver disease preoperatively treated with oxaliplatin and capecitabine because of CLMs who developed nodu- lar regenerative hyperplasia (NRH) of the liver causing deleterious complications after major hemihepatectomy. Interestingly, one of these patients underwent limited repeat resections after 12 and 18 months because of recurrent CLMs, after which the clinical courses were uneventful. 2. Patient Cases Case 1. A 68-year-old man was referred to our hospi- tal because of synchronous CLMs. His medical history revealed a colorectal carcinoma (pT3N0M1) treated by right hemicolectomy. Neoadjuvant chemotherapy consisting of 6 cycles of oxaliplatin (130 mg/m2) and capecitabine (1000 mg/m2 2-times daily) was initiated after resection of the colorectal primary. The patient had no history of liver disease and computed tomography (CT) scan