title: Morphological study and comprehensive cellular constituents of milky spots in the human omentum.
abstract: OBJECTIVE
  To analyze morphological features of omental milky spots (MS).
  
  
  METHODS
  Hematoxylin-eosin staining and immunohistochemistry technique were used to study the omental MS of gastric cancer (GC) patients and rectal cancer (RC) patients. We focused on morphological features of MS and conducted quantitative analysis on the cells number and cellular constituents. Differences in MS parameters between GC and RC were also analyzed.
  
  
  RESULTS
  Various shapes of MS were mainly round, oval, irregular form in the adipose and perivascular annular. The median MS perimeter was 2752 (range 817~7753) computer-based pixels. The median value of immune cells in one MS was 141 (43~650), comprising T lymphocytes (46.1%), B lymphocytes (28.4%), macrophages (12.4%) and other immune cells (13.1%). Relatively high density of vessels in MS could be calculated by micro-vessel density (MVD) as 4 (0~13). The median value of mesothelial cells loosely arranged in the surface layer was 5 (0~51). There were no significant differences in MS perimeter, MVD, the number of mesothelial cells, total immune cells, T lymphocytes and macrophages between GC and RC (P>0.05), while the number of MS B lymphocytes in RC was significantly higher than that in GC (P<0.001).
  
  
  CONCLUSIONS
  MS are primary immune tissues in the omentum and structural bases for development and progression of peritoneal dissemination of GC and RC. Analyzing the morphology and cellular constituents could help understanding the mechanism of peritoneal metastasis.
authors.affiliation: Department of Oncology, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center Wuhan 430071, Hubei Province, China.
authors.forename: Jiu-Yang
authors.initials: JY
authors.lastname: Liu
authors.affiliation: Department of Pathology, Renmin Hospital of Wuhan University Wuhan, Hubei Province, China.
authors.forename: Jing-Ping
authors.initials: JP
authors.lastname: Yuan
authors.affiliation: Department of Oncology, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center Wuhan 430071, Hubei Province, China.
authors.forename: Xia-Fei
authors.initials: XF
authors.lastname: Geng
authors.affiliation: School of Computer, Wuhan University Wuhan 430071, Hubei Province, China.
authors.forename: Ai-Ping
authors.initials: AP
authors.lastname: Qu
authors.affiliation: Department of Oncology, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center Wuhan 430071, Hubei Province, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
mesh_terms: D001402:B-Lymphocytes / Q000473:pathology; D006801:Humans; D008264:Macrophages / Q000473:pathology; D009852:Omentum / Q000473:pathology*; D013274:Stomach Neoplasms / Q000473:pathology*; D013601:T-Lymphocytes / Q000473:pathology
keywords: Milky spot; gastric cancer; omentum; peritoneal metastasis; rectal cancer