Kidney tumor - cysts, children, adult benign
Adult renal carcinoma
Multilocular cystic renal neoplasm of low malignant potential

Authors: Nicole K. Andeen, M.D., Maria Tretiakova, M.D., Ph.D. (see Authors page)

Revised: 1 February 2017, last major update July 2016

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

PubMed search: Multilocular cystic renal cell carcinoma kidney
Cite this page: Multilocular cystic renal neoplasm of low malignant potential. PathologyOutlines.com website. http://pathologyoutlines.com/topic/kidneytumormcrnlow.html. Accessed May 29th, 2017.
Definition / general
  • "Neoplasm composed entirely of numerous cysts, the septa of which contain individual or groups of clear cells without expansile growth" (WHO 2016)
Essential features
  • Multicystic; no expansile growth
  • Clear cells with low grade nuclei (ISUP grade 1 or 2)
  • No recurrence or metastases when diagnosed on strict criteria
  • Distinguish from regressing clear cell renal cell carcinoma (ccRCC) with cystic degeneration, which often has cysts filled with hemorrhage, necrosis and hemosiderin deposits; may have extensive hyalinization and often has areas of expansile growth of neoplastic cells
Terminology
  • 2016 WHO separates this neoplasm of low malignant potential from cystic renal cell carcinomas which have some overlapping morphologic features
  • Use of "multilocular cystic renal cell carcinoma" is considered obsolete (WHO 2016); some literature references in this topic use the older terminology
Epidemiology
  • Accounts for less than 1% of all renal tumors
  • Middle age adults
  • Male:female ratio ranges from 1.2:1 to 2.1:1
Sites
  • Kidney only
Clinical features
Diagnosis
  • There are no current guidelines or definitive evidence regarding the question of whether complete histologic examination is required for diagnosis (Am J Surg Pathol 2013;37:1469)
Case reports
Treatment
  • Resection, preferably nephron sparing surgery
Gross description
  • Usually unilateral and less than 5 cm
  • Variably sized cysts filled with clear, serous or gelatinous fluid; much less commonly hemorrhagic debris
  • No mural nodules
Gross images

Images hosted on other servers:

Large multi-cystic mass

Cysts filled with gelatinous material

Microscopic (histologic) description
  • Thin fibrous septae with clear cells lining the septa or in small clusters
  • Low grade nuclei without nucleoli (ISUP grade 1 - 2)
  • Cyst lining may be denuded and bland clear cells in septa may be mistaken for lymphocytes; look for vascularity
  • No expansile growth of clear tumor cells / solid nodules
  • No necrosis, vascular invasion or sarcomatoid change
  • In rare cases, lining of cysts may show multilayering, cells with granular cytoplasm and small intracystic papillations
  • Septa may contain calcification or ossification
Microscopic (histologic) images

Images hosted on other servers:

Cyst wall lined by clear cells

Cysts filled with hemorrhagic material

Various images

Positive stains
Negative stains
Molecular / cytogenetics description
Differential diagnosis