[1] UCL, Dept Histopathol, London WC1E 6JJ, England
[2] Lariboisiere Hosp, Dept Pathol & Cytopathol, Paris, France
[3] Univ Hosp 12 Octubre, Pathol Serv, Madrid, Spain
[4] Univ Ziekenhuis, Unit Cytol & Gynecopathol, Brussels, Belgium
[5] Guys & St Thomas NHS Fdn Trust, Dept Cellular Pathol, London, England
[6] Shiraz Sch Med, Pathol Lab, Shiraz, Iran
[7] St Georges Hosp NHS Trust, London, England
[8] St Georges Med Sch, London, England
[9] Charles Univ Prague, Fac Med 1, Inst Pathol, Prague, Czech Republic
[10] Cukurova Univ, Sch Med, Dept Pathol & Cytol, Adana, Turkey
[11] Catholic Univ, Agostino Gemelli Sch Med, Div Anat Pathol & Histol, Rome, Italy
[12] Dept Diagnost Med Sci & Special Therapies, Sect Pathol, Unit Cytopathol, Padua, Italy
[13] Hacettepe Univ, Fac Med, Dept Pathol, TR-06100 Ankara, Turkey
[14] Inst Jimenez Ayala, Madrid, Spain
[15] Univ Athens, Attikon Hosp, Dept Cytopathol, GR-10679 Athens, Greece
[16] Med Univ Vienna, Clin Inst Pathol, Vienna, Austria
[17] Sister Mercy Hosp, Lab Thyroid Cytopathol, Dept Oncol & Nucl Med, Zagreb, Croatia
[18] Queen Alexandra Hosp, Dept Histopathol, Portsmouth, Hants, England
[19] Onze Lieve Vrouw Hosp, Histo & Cytopathol Labs, Aalst, Belgium
[20] Charles Univ Prague, Med Fac Hosp, Fingerland Dept Pathol, Hradec Kralove, Czech Republic
[21] Tech Univ Munich, Inst Pathol, D-8000 Munich, Germany
[22] Univ Oslo, Ulleval Hosp, Dept Pathol, N-0316 Oslo, Norway
[23] Univ Porto, IPATIMUP, P-4100 Porto, Portugal
[24] Univ Porto, Fac Med, P-4100 Porto, Portugal
[25] Karolinska Univ Hosp Solna, Dept Pathol & Cytol, Stockholm, Sweden
[26] PSHP Lab Ctr, Tampere, Finland
[27] Univ Hosp Graz, Inst Cytol, Graz, Austria
[28] Univ Naples Federico II, Dept Biomorphol Sci, Naples, Italy
[29] Univ Hosp Pest Cty, Dept Pathol Cytopathol, Kistarcsa, Hungary
[30] Inst Gustave Roussy, Dept Pathol, Villejuif, France