title: Expression of erythropoietin receptor in human Merkel cell carcinoma of the eyelid.
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) of the eyelid is a rare malignant solid tumor of the elderly, which demonstrates a large, firm, reddish nodule mimicking an angiomatous lesion. The expression of erythropoietin (Epo) and Epo receptor (EpoR), as well as vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR) and basic fibroblast growth factor (bFGF) were examined in human MCC tissues.
  
  
  METHODS
  Three patients diagnosed with MCC of the eyelid underwent surgical excision. Isolated tissues were fixed by 4% paraformaldehyde and then were examined using immunohistochemistry.
  
  
  RESULTS
  The carcinoma cells consisted of irregular tumor nests with linear stroma and showed hypercellularity indicated by small round nuclei with several mitoses. While immunoreactivity of Epo was undetectable, an increased expression of EpoR was noted in the carcinoma cells. Cytoplasmic immunoreactivity for EpoR was detected in a variety of carcinoma cells, including mitotic cells. VEGF, VEGFR, and bFGF, other angiogenic factors were not expressed in the MCC tissues.
  
  
  CONCLUSIONS
  EpoR was highly expressed in MCC of the eyelid, suggesting that the Epo-EpoR pathway plays an important role in the formation of MCC.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Hokkaido University Graduate School of Medicine, N15 W7, Kita-ku, Sapporo, 060-8638 Japan. kaseron@med.hokudai.ac.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Kase
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yoshida
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Osaki
authors.forename: Hironobu
authors.initials: H
authors.lastname: Adachi
authors.forename: Hisao
authors.initials: H
authors.lastname: Ito
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Ohno
mesh_terms: D015266:Carcinoma, Merkel Cell / Q000378:metabolism*; D005142:Eyelid Neoplasms / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism
chemical_list: D040262:Receptors, Vascular Endothelial Growth Factor