Bladder, ureter & renal pelvis

Urothelial carcinoma - invasive

Sarcomatoid variant



Topic Completed: 14 May 2021

Minor changes: 21 May 2021

Copyright: 2003-2021, PathologyOutlines.com, Inc.

PubMed Search: Urothelial carcinoma sarcomatoid renal pelvis

See also: Urothelial carcinoma of renal pelvis

Megan L. Brown, M.D.
Maria Tretiakova, M.D., Ph.D.
Page views in 2021 to date: 3,323
Cite this page: Brown ML, Tretiakova M. Sarcomatoid variant. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bladdersarcomatoidvariant.html. Accessed December 3rd, 2021.
Definition / general
  • Variant of urothelial carcinoma; morphologically indistinguishable from sarcoma
  • Heterologous elements may be present (Histopathology 2019;74:77)
Essential features
  • Biphasic malignant neoplasm with morphologic and immunohistochemical evidence of both epithelial and mesenchymal differentiation
  • Rare (0.3 - 0.6% of all urothelial carcinomas) and biologically aggressive variant
  • Associated with radiation therapy or cyclophosphamide
  • If present, heterologous elements should be mentioned in the report
Terminology
  • WHO recommends the term sarcomatoid variant of urothelial carcinoma for these biphasic malignant neoplasms
  • Terms carcinosarcoma, metaplastic carcinoma, spindle cell carcinoma and malignant mixed tumor have been used interchangeably but can lead to confusion and are therefore discouraged
ICD coding
  • Location based ICD-10 coding:
    • Renal pelvis, including pelviureteric junction and renal calyces
      • C65.1 - malignant neoplasm of right renal pelvis
      • C65.2 - malignant neoplasm of left renal pelvis
      • C65.9 - malignant neoplasm of unspecified renal pelvis
    • Ureter, including ureteric orifice of bladder
      • C66.1 - malignant neoplasm of right ureter
      • C66.2 - malignant neoplasm of left ureter
      • C66.9 - malignant neoplasm of unspecified ureter
    • Bladder
      • C67.0 - malignant neoplasm of trigone of bladder
      • C67.1 - malignant neoplasm of dome of bladder
      • C67.2 - malignant neoplasm of lateral wall of bladder
      • C67.3 - malignant neoplasm of anterior wall of bladder
      • C67.4 - malignant neoplasm of posterior wall of bladder
      • C67.5 - malignant neoplasm of bladder neck
      • C67.6 - malignant neoplasm of ureteric orifice
      • C67.7 - malignant neoplasm of urachus
      • C67.8 - malignant neoplasm of overlapping sites of bladder
      • C67.9 - malignant neoplasm of bladder, unspecified
    • Other, unspecified urinary organs
      • C68.0 - malignant neoplasm of urethra
      • C68.1 - malignant neoplasm of paraurethral glands
      • C68.8 - malignant neoplasm of overlapping sites of urinary organs
      • C68.9 - malignant neoplasm of urinary organ, unspecified
Epidemiology
Sites
  • Kidney pelvis, proximal ureter and bladder
Pathophysiology
Etiology
  • Probably has a common malignant clonal origin, with epithelial and mesenchymal differentiation (J Pathol 2007;211:420)
  • Common final pathway of all forms of bladder tumors, supported by molecular and morphologic evidence (Histopathology 2019;74:77)
  • Risk factors include previous exposure to radiotherapy and intravesicular cyclophosphamide (Eur Urol Focus 2020;6:653)
Clinical features
  • Gross hematuria, flank pain, an abdominal mass and hydronephrosis
  • Similar to those of conventional urothelial tumors
  • Reference: ISRN Urol 2014;2014:794563
Diagnosis
Laboratory
  • Hematuria
Radiology description
  • Thickened bladder wall with or without intraluminal papillary or nodular mass; heterologous elements such as calcification in osteosarcoma may be demonstrated (Radiographics 2006;26:553)
Prognostic factors
  • Poor prognosis, as frequently presents at an advanced stage and is associated with a worse overall survival when compared with pure urothelial carcinoma (Eur Urol Focus 2020;6:653)
  • Similar to bladder, sarcomatoid urothelial carcinoma of renal pelvis has a worse prognosis on univariate analysis (ISRN Urol 2014;2014:794563, Oncol Lett 2014;8:1208, J Urol 2012;188:398)
  • Associated with higher tumor stage, multifocality, tumor necrosis, frequent metastases at presentation; however, insufficient case numbers in kidney to confirm independent negative prognostic impact on multivariate analysis (J Urol 2012;188:398)
  • May have heterologous elements, without definite prognostic significance (Mod Pathol 2009;22:S96)
Case reports
Treatment
Gross description
  • Gray fleshy cut surface with infiltrative margins similar to sarcoma in appearance
Gross images

Contributed by Nicole K. Andeen, M.D. and Maria Tretiakova, M.D., Ph.D.
Mass involving hilum

Mass involving hilum

Frozen section description
  • Not typically diagnosed on frozen section
Microscopic (histologic) description
  • Most common component is undifferentiated high grade spindle cell sarcoma (Histopathology 2019;74:77)
  • Sarcomatoid areas admixed with conventional high grade urothelial carcinoma
  • Spindle cell component may account for 10% to > 60% of tumor
  • Epithelial component has urothelial differentiation or less commonly squamous or glandular differentiation
  • Highly variable and can mimic nonepithelial neoplasms (J Biol Chem 2019;294:1579)
  • Most common heterologous element is osteosarcoma, followed by chondrosarcoma, rhabdomyosarcoma, leiomyosarcoma, liposarcoma and angiosarcoma (Histopathology 2019;74:77)
Microscopic (histologic) images

Contributed by Megan L. Brown, M.D., Nicole K. Andeen, M.D. and Maria Tretiakova, M.D., Ph.D.
High grade spindled to epithelioid cells

High grade spindled to epithelioid cells

Elongated spindled cells

Elongated spindled cells

Classic urothelial carcinoma

Classic urothelial carcinoma

Neoplasm with admixed carcinomatous and sarcomatous elements Neoplasm with admixed carcinomatous and sarcomatous elements

Neoplasm with admixed carcinomatous and sarcomatous elements


GATA3 and CK7 GATA3 and CK7

GATA3 and CK7

Virtual slides

Images hosted on other servers:
Urothelial carcinoma with sarcomatoid differentiation, high grade Urothelial carcinoma with sarcomatoid differentiation, high grade

Urothelial carcinoma with sarcomatoid differentiation, high grade

Urothelial carcinoma with extensive sarcomatoid features

Sarcomatoid urothelial
carcinoma involving
muscularis propria

Positive stains
Molecular / cytogenetics description
Sample pathology report
  • Bladder, transurethral resection:
    • High grade urothelial carcinoma with sarcomatoid differentiation (80%) (see comment)
    • Comment: Invasive of muscularis propria (T2)
    • Angiolymphatic invasion absent
    • Muscularis propria present, involved by tumor
Differential diagnosis
Board review style question #1

A 65 year old presented with bladder wall thickening on ultrasound. Transurethral resection of bladder tumor is performed and shows a lesion with features on H&E as seen in the image shown above. Which of the following is likely in the patient’s medical history?

  1. Asbestos exposure
  2. Family history of prostate adenocarcinoma
  3. High nitrate consumption in their diet
  4. Intravesical cyclophosphamide
  5. Woodworking hobby
Board review style answer #1
D. Intravesical cyclophosphamide has been associated with the development of sarcomatoid variant of urothelial carcinoma (Eur Urol Focus 2020;6:653)

Comment Here

Reference: Sarcomatoid variant
Board review style question #2

What is the most commonly identified heterologous element identified in association with the pictured lesion?

  1. Chondrosarcoma
  2. Leiomyosarcoma
  3. Liposarcoma
  4. Osteosarcoma
  5. Rhabdomyosarcoma
Board review style answer #2
D. Osteosarcoma is the most commonly identified heterologous element in the sarcomatoid variant of urothelial carcinoma (Histopathology 2019;74:77)

Comment Here

Reference: Sarcomatoid variant
Back to top
Image 01 Image 02