title: Reactive lymphoid hyperplasia of the liver in a patient with colon cancer: report of two cases.
abstract: BACKGROUND
  Reactive lymphoid hyperplasia (RLH) of the liver is very rarely reported, and we encountered two cases of RLH of the liver in a patient with colon cancer.
  
  
  METHODS
  In the first case, a 77-year-old woman was admitted for the surgical removal of a ascending colon cancer. A hepatic tumor in the left lobe was concurrently revealed by computed tomography (CT), and magnetic resonance imaging (MRI). The appearance suggested liver metastasis. Right hemicolectomy and partial hepatectomy were performed. On histopathological examination, lymphoid follicles with germinal centers were seen in the tumor-like lesion, and remarkable lymphoid infiltration with germinal centers was seen in the portal area around the nodule. Immunohistochemical studies revealed polyclonality of infiltrating lymphocyte. Consequently, this nodular lesion was diagnosed as RLH of the liver. In the second case, a 64-year-old woman who had a radical right hemicolectomy for stage II ascending colon cancer 10 years ago was admitted with dysuria. A hepatic tumor in the left lobe was concurrently revealed by CT and MRI, suggesting hepatocellular carcinoma. A left lateral segmentectomy was performed. Microscopically, this lesion revealed the almost same findings as the first case, so this nodular lesion was diagnosed as RLH of the liver.
  
  
  CONCLUSIONS
  Our two cases were the first report of RLH of the liver accompanying colon cancer. Because there are a very few cases, so it is not clear whether the malignancies were involved in the onset of RLH. But we believe that new factors involved in the onset mechanism of RLH may be identified by carefully monitoring the clinical course of our two patients.
authors.affiliation: Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya, Japan. takahasi@med.nagoya-cu.ac.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Hirozumi
authors.initials: H
authors.lastname: Sawai
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Funahashi
authors.forename: Mikinori
authors.initials: M
authors.lastname: Satoh
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Takeyama
authors.forename: Tadao
authors.initials: T
authors.lastname: Manabe
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000601:surgery; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology; D003110:Colonic Neoplasms / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D005743:Gastrectomy; D006498:Hepatectomy; D006505:Hepatitis / Q000453:epidemiology; D006801:Humans; D007150:Immunohistochemistry; D008107:Liver Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D019310:Pseudolymphoma / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery