MiT Family Translocation Renal Cell Carcinoma
Definition
- Renal carcinoma associated with gene fusions in MiT family transcription factors TFE3 or TFEB
Alternate/Historical Names
- Juvenile renal cell carcinoma
- Xp11/TFE3 translocation carcinoma
Diagnostic Criteria
- Presence of translocation of TFE3 or TFEB
- May be demonstrated by classical cytogenetics, PCR or FISH
- Demonstration may not be required in every case
- Most common abnormalities are t(6;11) between TFEB and Alpha/MALAT1
- Immunohistochemistry showing strong nuclear staining for TFEB is highly specific for t(6;11)
- Less common is fusion Xp11 of TFE3 and ASPL
- Immunohistochemistry showing strong nuclear staining with antibody to the C terminus of TFE3 is highly sensitive and specific for Xp11
- Break apart FISH may be useful and less sensitive to fixation effects
- Xp11 and t(6;11) tumors can overlap morphologically
- Compoed of cells with abundant to voluminous cytoplasm
- Clear to granular eosinophilic cytoplasm
- Sharp cell borders
- Pleomorphic and polymorphic growth patterns
- Frequent papillary, pseudopapillary, alveolar and nested patterns
- Bbiphasic appearance with clusters of small cells centered on hyaline cores may be seen
- Collections of small cells should suggest a t(6;11) carcinoma
- Compoed of cells with abundant to voluminous cytoplasm
- Patterns and cells may vary according to the precise translocation involved
- Large vesicular nuclei
- Prominent round nucleoli
- Mitotic figures frequent
- Features frequently present
- Psammoma bodies may be abundant
- Intracytoplasmic hyaline droplets
- May coontain melanin pigment and express melanocytic markers
- Negative to weak keratn and EMA staining
- Most cases reported in children and young adults
- Under-recognized in adults
- Two studies find an incidence of 1-5% in adults (Zhong, Sukov)
- If possible, fresh tumor tissue should be sent for cytogenetics in all renal tumor patients under 40 years of age and in older patients in which an unusual tumor is discovered at frozen section
- Under-recognized in adults
Kurt Schaberg MD
John P Higgins MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting: 11/21/16
