Newborn female, palpable tumour of right kidney. In the ultrasound examination a multicystic lesion is noted. Nephrectomy
- No recognisable architecture of the kidney.
- Large cysts, which are lined with squamous to cuboidal epithelium.
- The surrounding connective tissue is loose, partly immature and contains different grades of differentiation (metaplasia), especially myxoid and chondroid parts (chondroid metaplasia).
- Located within the connective tissue are immature tubuli which are surrounded by cell-rich (immature cells) connective tissue in a circular fashion.
- The cysts are partly surrounded by similar circular, yet mature fibrous connective tissue.
Pathogenesis: A disturbance in the nephroblastem formation (dysplasia) can have a multicystic manifestation. a . This corresponds to a disturbed development of the kidney in utero and is accompanied by urine drainage problems of the fetus.