Kidney tumor
Adult renal cell carcinoma
Tubulocystic carcinoma

Author: Daniel Anderson, M.D. MBA
Editor: Maria Tretiakova, M.D., Ph.D.
Deputy Editor: Debra Zynger, M.D.

Revised: 30 July 2018, last major update May 2018

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Tubulocystic carcinoma kidney

Cite this page: Anderson, D. Tubulocystic renal cell carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/kidneytumormalignanttubulocystic.html. Accessed October 21st, 2018.
Definition / general
  • Renal epithelial neoplasm composed predominately of tubules and cysts lined by a single layer of cells with prominent nucleoli (ISUP grade 3) and abundant eosinophilic cytoplasm (Eur Urol 2016;70:93)
  • Relatively indolent with < 10% cases showing disease progression, local recurrence or metastasis to bone, liver and lymph nodes (Eur Urol 2016;70:93)
  • Recognized by the 2016 WHO classification
Essential features
  • Well circumscribed tumor with spongy bubble wrap appearance
  • Strong male predominance
  • Pure cystic and tubular architecture; no solid areas
  • Single layer of flat, cuboidal or hobnailed eosinophilic cells along fibrotic septa
Terminology
ICD-10 coding
  • C64-: malignant neoplasm of kidney, except renal pelvis
Epidemiology
Pathophysiology
  • Histogenesis remains unclear; cells have some features of proximal nephron differentiation and others relate to distal nephron (Can Urol Assoc J 2015;9:E654)
Clinical features
  • Often an incidental finding with ~90% low stage
  • Less commonly presents with abdominal pain, distention, hematuria, weight loss
  • Prognosis is typically excellent with rare recurrences, distant metastases or death from disease
Case reports
Treatment
  • Radical or partial nephrectomy depending on tumor size and location in the kidney
  • No established targeted therapy in metastases but a few case reports suggest a partial response to sunitinib (a tyrosine kinase inhibitor) and everolimus (a mammalian target of rapamycin [mTOR] inhibitor) (Rev Urol 2016;18:118)
Gross description
  • Well circumscribed but not encapsulated
  • Cut surface that is grey white with multilocular cystic spaces resembling a sponge, Swiss cheese or bubble wrap appearance
  • Mean size 4 cm (range 0.2 - 17 cm)
  • No hemorrhage or necrosis
Gross images

Images hosted on PathOut server:

Contributed by
Daniel Anderson, M.D.

Partial nephrectomy with tubulocytic RCC


Case of the Week
#51

Cystic lesion



Images hosted on other servers:

Brown, fleshy tumour with numerous cysts

Tubulocystic renal cell carcinoma

Microscopic (histologic) description
  • Mixture of closely packed tubules and variably sized cysts with overall low grade morphology (Urology 1997;50:679)
  • Cysts are separated by fibrous septa; no desmoplasia or cellular stroma
  • Tubules and cysts are lined by a single layer of flattened, cuboidal or columnar cells; hobnailing may be present with modest to abundant amounts of eosinophilic cytoplasm resembling oncocytoma cells
  • Uniform round nuclei with distinct nucleoli (ISUP grade 3)
  • Association with papillary cell neoplasms is not uncommon
  • Minimal mitotic activity and atypia, very rare necrosis
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Maria Tretiakova, M.D., Ph.D.

Tubules and variably sized cysts lined by cuboidal epithelium

Hobnailing and distinct nucleoli



Images contributed by Sabrina Sopha, M.D.
Missing Image

H&E stained sections showing cysts and tubules lined by cuboidal epithelium with scattered hobnailing


Missing Image

IHC images show cytoplasmic CD10, CK7 and EMA positivity

Tubulocystic carcinoma



Images hosted on other servers:

Low magnification
of tubules and
cysts

   

Tubules lined by cuboidal epithelium

   

Eosinophilic cytoplasm
resembling oncocytoma
cells and distinct nucleoli

Positive stains
Negative stains
Electron microscopy description
  • Short microvilli with brush border organization
  • Ultrastuctural features resembling both cells of the proximal tubules and collecting ducts
Electron microscopy images

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Type I and type II cells

Molecular / cytogenetics description
Differential diagnosis
Board review question #1
The neoplasm shown in the picture is a recently recognized distinct entity of the kidney that has all the following features, except:


  1. Few neoplasms progress and metastasize
  2. It consists of a mixture of tubules and micro/macro cysts lined by hobnailed cells
  3. Male predominance
  4. Neoplasm contains stromal hypercellularity (including ovarian type stroma)
  5. Sponge-like or bubble wrap gross appearance
Board review answer #1
D. Stromal hypercellularity and ovarian type stroma is a feature of adult cystic nephroma / mixed epithelial and stromal tumor.