Testis and epididymis
Paratesticular tumors
Brenner tumor

Author: Jennifer Gordetsky, M.D. (see Authors page)

Revised: 9 June 2017, last major update August 2013

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: Brenner tumor testis
Cite this page: Brenner tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisbrenner.html. Accessed December 11th, 2018.
Definition / general
  • Extremely rare tumor of testis and paratesticular regions composed of transitional type epithelium; usually occurs in ovary
  • Also called transitional cell tumor
  • Age range 37 - 70 years (mean 57.7)
  • Etiology unknown; may originate from Walthard rests within tunica vaginalis or transitional epithelial nests located in testicular / paratesticular locations
Clinical features
  • Testicular mass, testicular pain
  • Must rule out metastatic urothelial carcinoma
Radiology description
  • Ultrasound remains imaging modality of choice for evaluation of scrotal masses
Prognostic factors
Case reports
  • Orchiectomy
Gross description
  • Solid and cystic masses, 1 to 5 cm
Microscopic (histologic) description
  • Nests of transitional cells (solid or cystic) with fibrous or cellular spindle cell stroma
  • Nests show mostly a pavement type arrangement with some focal columnar type cell appearance
  • Nuclei are round to oval, some with nucleoli and longitudinal nuclear grooves
  • Focal mucinous differentiation has been reported
Microscopic (histologic) images

Images hosted on other servers:

Solid and cystic nests

Transitional epithelial cells

Nests of transitional cells

Irregular nests of
benign transitional
(urothelial) cells

Positive stains
  • CK7: cytoplasmic staining
  • Uroplakin III: cytoplasmic and membrane staining
  • WT1: focal; nuclear staining
Negative stains
Electron microscopy description
  • Cells with complex interdigitations interlocking their plasma membranes, which are otherwise joined by tight desmosomes
  • Small intercellular spaces containing elongated projections of cytoplasm
  • Cytoplasm contains microfilaments, poorly preserved mitochondria and ribosomes
  • Deep nuclear clefts (Cancer 1979;43:539)