title: MiT translocation renal cell carcinomas: two subgroups of tumours with translocations involving 6p21 [t (6; 11)] and Xp11.2 [t (X;1 or X or 17)].
abstract: BACKGROUND
  MiT translocation renal cell carcinomas (TRCC) predominantly occur in younger patients with only 25% of patients being over 40 years. TRCC contains two main subgroups with translocations involving 6p21 or Xp11.2. Herein we present 10 cases.
  
  
  METHODS
  Eight cases were treated at main author's institution (identified among 1653 (0.48%) cases of kidney tumours in adults). Two cases were retrieved from the Pilsen (CZ) Tumour Registry.
  
  
  RESULTS
  Six cases were type Xp11.2 and four 6p21; 7 female, 3 male patients; Xp11.2 4:2, 6p21 3:1. The mean age 49 years (range: 21-80), 5 patients (50%) over 40 years. The mean age of the group with Xp11.2 TRCCs was 55 (median 51) and 6p21 41 (32) years. One female with a 6p21 tumour (24 years) underwent nephrectomy at 4 months of pregnancy. Stage (UICC, 7th ed. 2009) was 5xI, 3xIII, 2xIV. The mean size of tumour was 80 (40-165) mm. The mean follow-up was 33.2 (1-92) months. In patients with 6p21 tumours, one (25%) died after 3 months due to widely metastatic disease. In patients with Xp11.2 tumours, 3 (50%) succumbed due to metastatic disease (range 1-8 months). Three patients with Xp11.2 are alive at 7, 52 and 92 months of follow-up, were diagnosed at early stage (T1a).
  
  
  CONCLUSIONS
  TRCCs were more common in females. Patient with 6p21 tumours were younger than those with Xp11.2. Both types have definitive malignant potential Type Xp11.2 seems to be a more aggressive neoplasm than 6p21. The case with metastatic 6p21 tumour is the 4th case described in the English literature.
authors.affiliation: Department of Urology Faculty Hospital, E. Beneše 13, Pilsen, 305 99 Czech Republic ; Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Milan
authors.initials: M
authors.lastname: Hora
authors.affiliation: Department of Urology Faculty Hospital, E. Beneše 13, Pilsen, 305 99 Czech Republic ; Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Urge
authors.affiliation: Department of Urology Faculty Hospital, E. Beneše 13, Pilsen, 305 99 Czech Republic ; Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Trávníček
authors.affiliation: Department of Radiology, Pilsen, Czech Republic ; Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Ferda
authors.affiliation: Department of Radiology, Pilsen, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Chudáček
authors.affiliation: Department of Pathology, Faculty Hospital in Pilsen, Pilsen, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Vaněček
authors.affiliation: Department of Pathology, Faculty Hospital in Pilsen, Pilsen, Czech Republic ; Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Michal
authors.affiliation: Department of Pathology, National University Health System, Singapore, Singapore.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Petersson
authors.affiliation: Department of Diagnostic Pathology, Kochi Red Cross Hospital, Kochi, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kuroda
authors.affiliation: Department of Pathology, Faculty Hospital in Pilsen, Pilsen, Czech Republic ; Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Hes