Kidney tumor
Childhood tumors
Anaplastic sarcoma of the kidney
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Deputy Editor-in-Chief: Maria Tretiakova, M.D., Ph.D.
Last author update: 7 November 2024
Last staff update: 7 November 2024
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PubMed Search: Anaplastic sarcoma of the kidney
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style question #1 | Board review style question #2 | Board review style answer #2Cite this page: Galluzzo Mutti ML, Vujanic GM. Anaplastic sarcoma of the kidney. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/kidneyanaplasticsarcoma.html. Accessed December 21st, 2024.
Definition / general
- Anaplastic sarcoma of the kidney is a polyphenotypic sarcoma associated with DICER1 mutations
- First described by Vujanić et al. in 2007 (Am J Surg Pathol 2007;31:1459)
Essential features
- Rare malignant tumor, with ~50 cases reported in the literature
- Belongs to DICER1 associated tumors
- Occurs in children and adults (age: 7 months - 41 years)
- Histologically characterized by sheets of spindle cells and undifferentiated morphology, marked anaplasia and islands of benign or malignant cartilage or chondroid differentiation
- Often contains a cystic component (cystic nephroma-like)
Terminology
- DICER1 sarcoma of the kidney
ICD coding
- ICD-O: 8802/3 - anaplastic sarcoma of the kidney
Epidemiology
- Only ~50 cases reported in the literature (Pediatr Blood Cancer 2024;71:e31090, World J Clin Cases 2020;8:1495)
- Age at presentation: 7 months - 41 years (Am J Surg Pathol 2007;31:1459, Pediatr Blood Cancer 2024;71:e31090)
- Median age: 8 years; 20/28 (71%) patients under the age of 15 years (World J Clin Cases 2020;8:1495)
- Female predominance (F:M = 2:1) (Pediatr Blood Cancer 2024;71:e31090, World J Clin Cases 2020;8:1495)
Sites
- Kidney
- Unilateral tumors
- Only 1 bilateral case reported (JCO Precis Oncol 2018;2:PO.17.00113)
Pathophysiology
- Majority (or even all) have a somatic RNase IIIb DICER1 mutation
- DICER1 is an endoribonuclease central to generating microRNAs (miRNAs)
- DICER1 utilizes its RNase IIIa and IIIb endonuclease domains to cleave precursor (pre)miRNA stem loops, thus releasing the mature single strand miRNA (Mod Pathol 2018;31:169)
- Co-occurrence of a TP53 mutation with DICER1 was confirmed in some cases but it is not a useful molecular marker of the disease (Mod Pathol 2018;31:169)
Etiology
- DICER1 mutations are the major genetic event in the development of anaplastic sarcoma of the kidney (Mod Pathol 2018;31:169)
Clinical features
- Large (and palpable) tumors
- Hematuria
- Flank pain
- Stage distribution (Pediatr Blood Cancer 2024;71:e31090)
- Stage I: 32.5%
- Stage II: 30%
- Stage III: 25%
- Stage IV: 12.5%
Diagnosis
- Histologic features (see Microscopic description) are usually diagnostic
- DICER1 mutations should be done to confirm the diagnosis
Prognostic factors
- No histological features associated with outcome
- Older age at presentation associated with worse outcomes (Pediatr Blood Cancer 2024;71:e31090)
- Out of 28 reported cases, 22 had documented followup data (World J Clin Cases 2020;8:1495)
- 68% of patients had no recurrence
- 4.5% had local recurrence
- 27% had distant metastases
- Genetic testing for DICER1 mutation and counseling should be offered (Mod Pathol 2014;27:1267)
Case reports
- 3 year old girl with a large abdominal mass (Int J Surg Pathol 2016;24:556)
- 12 year old girl with buttock pain and urinary incontinence (Hum Pathol 2010;41:1495)
- 13 year old boy with a large renal mass (Pediatr Int 2013;55:e129)
- 27 year old woman with a palpable mass over the abdomen (World J Clin Cases 2020;8:1495)
Treatment
- No standardized treatment
- Treated with primary or delayed surgery, followed by chemotherapy and radiotherapy (for higher stages)
- 2 year event free survival
- Stage I - II: 82%
- Stage III - IV: 47%
- 2 year overall survival (Pediatr Blood Cancer 2024;71:e31090)
- Stage I - II: 89%
- Stage III - IV: 70%
Gross description
- Typically large (median size: 12.5 cm)
- Centrally located in the kidney
- Most tumors have a distinct cystic component
- Reference: JCO Precis Oncol 2022;6:e2100554
Gross images
Contributed by Erdener Özer, M.D., Ph.D.
Tumor with solid and cystic parts
Microscopic (histologic) description
- Typical features
- Undifferentiated cells
- Spindle cell areas
- Marked diffuse anaplasia
- Benign or malignant cartilage or chondroid differentiation
- Rhabdomyoblastic differentiation (desmin and myogenin positivity)
- Cystic nephroma-like cystic component
- May have
- Osteoid differentiation
- Ganglioneuroblastic differentiation (Pediatr Dev Pathol 2022;25:186)
- Staging criteria are the same as nephroblastoma (Histopathology 2022;80:1026)
Microscopic (histologic) images
Contributed by Maria Laura Galluzzo Mutti, M.D. and Gordan M. Vujanic, M.D., Ph.D.
Spindled pattern
Alternating cellularity
Blastema-like area
Diffuse anaplasia
Benign cartilage
Malignant cartilage
Anaplasia
Cystic nephroma-like areas
Cystic pattern
Positive stains
- Limited series tested; variable results
- p53
- Desmin
- Myogenin
- Vimentin
- PGP9.5
- References: Am J Surg Pathol 2007;31:1459, Pediatr Blood Cancer 2024;71:e31090
Negative stains
- WT1
- NB84a
- CD34
- CD99
- CK AE1 / AE3
- EMA
- BCOR
- PAX8
- CD56
- References: Am J Surg Pathol 2007;31:1459, Pediatr Blood Cancer 2024;71:e31090
Molecular / cytogenetics description
- Genetic pathogenesis of cystic nephroma to anaplastic sarcoma of the kidney parallels that of type I to type II / III malignant progression of pleuropulmonary blastoma (Mod Pathol 2014;27:1267)
- Cystic nephroma in patients with DICER1 syndrome may progress to anaplastic sarcoma of the kidney (Pediatr Blood Cancer 2016;63:1272)
Sample pathology report
- Kidney, total nephrectomy:
- Anaplastic sarcoma of the kidney, stage I (see comment)
- Comment: Tumor comprises solid and cystic components. The solid component shows spindle cell areas with marked, diffuse anaplasia and islands of cartilage with benign and malignant features. The cystic component looks like a cystic nephroma. It is advisable to do a DICER1 mutation test.
Differential diagnosis
- Wilms tumor with diffuse anaplasia:
- Presence of (immature or mature) epithelial structures
- WT1 is negative in anaplastic sarcoma of the kidney
- Nephrogenic rests are not present in anaplastic sarcoma of the kidney
- Primary renal synovial sarcoma:
- Usually exhibits a moderate to strong nuclear staining for TLE1 (but can be patchy positive in anaplastic sarcoma of the kidney) (JCO Precis Oncol 2022;6:e2100554)
- SS18::SSX fusion specific antibody: 95% sensitive, 100% specific
- SSX C terminus antibody: 100% sensitive, 96% specific (Am J Surg Pathol 2020;44:922)
- Mesenchymal chondrosarcoma:
- No DICER1 mutation
Additional references
Board review style question #1
A 9 year old boy presents with a painless macroscopic hematuria. Imaging studies revealed a cystic and solid mass in the right kidney. A total right nephrectomy was performed. Which of the following is the most characteristic pathologic finding for this tumor?
- Epithelial elements
- Marked, diffuse anaplasia
- Rhabdomyoblastic differentiation
- WT1 positive immunostaining
Board review style question #1
B. Marked, diffuse anaplasia is present in all cases of anaplastic sarcoma of the kidney. Answers A, C and D are incorrect because these features are not seen in anaplastic sarcoma of the kidney.
Comment Here
Reference: Anaplastic sarcoma of the kidney
Comment Here
Reference: Anaplastic sarcoma of the kidney
Board review style question #2
What is the specific molecular abnormality associated with anaplastic sarcoma of the kidney?
- BCOR internal tandem duplication (ITD)
- BRAF mutation
- DICER1 mutation
- MYCN amplification
Board review style answer #2
C. DICER1 mutation. DICER1 mutations are characteristically associated with anaplastic sarcoma of the kidney. Answer A is incorrect because BCOR ITD is associated with another renal tumor, clear cell sarcoma of the kidney. Answer B is incorrect because BRAF mutations are characteristically associated with metanephric renal tumors. Answer D is incorrect because MYCN amplification is not associated with anaplastic sarcoma of the kidney but with neuroblastoma.
Comment Here
Reference: Anaplastic sarcoma of the kidney
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Reference: Anaplastic sarcoma of the kidney
