BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors: A Close Mimic of Clear Cell Sarcoma of Kidney

Pedram Argani, Yu-Chien Kao, Lei Zhang, Yun Shao Sung, Rita Alaggio, David Swanson, Andres Matoso, Brendan C. Dickson, Cristina R. Antonescu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

BCOR immunoreactivity is a sensitive and highly specific marker for clear cell sarcoma of the kidney (CCSK). However, a subset of adult renal sarcomas which overexpress BCOR are negative for BCOR genetic alterations, including BCOR gene fusions or BCOR-internal tandem duplication, and thus remain unclassified. We report 5 such undifferentiated renal/perirenal sarcomas which raised the differential diagnosis of CCSK due to their morphologic appearance and strong BCOR immunoreactivity, but which on RNA sequencing proved to be malignant solitary fibrous tumors (SFTs). The neoplasms occurred in patients at an age range of 30 to 62 years. Three patients were females and 2 male. Four were primary renal neoplasms while one was perirenal. All 5 neoplasms were cellular, nonpleomorphic, undifferentiated sarcomas with branching capillary vasculature composed of primitive round to ovoid neoplastic cells with scant cytoplasm and nuclei having fine, evenly dispersed chromatin. None of the cases demonstrated the typical hyperchromatic fusiform nuclei, prominent collagen deposition, or hemangiopericytomatous vasculature of SFT. All 5 cases were strongly immunoreactive for BCOR. Three cases were CD34 negative, where the other 2 were only focally CD34 positive. STAT6 was subsequently found to be positive by immunohistochemistry in all 5 cases. In summary, we report a previously unrecognized mimic of CCSK: malignant SFTs with an undifferentiated/small round cell phenotype along with branching capillary vasculature, strong immunoreactivity for BCOR, and minimal or no immunoreactivity for CD34. As CCSK is treated with a specific chemotherapy regimen, this distinction has therapeutic implications.

Original languageEnglish
JournalAmerican Journal of Surgical Pathology
DOIs
Publication statusPublished - Jan 1 2019

Fingerprint

Clear Cell Sarcoma
Solitary Fibrous Tumors
Kidney
Sarcoma
RNA Sequence Analysis
Kidney Neoplasms
Gene Fusion
Chromatin
tebufenozide
Neoplasms
Cytoplasm
Differential Diagnosis
Collagen
Immunohistochemistry
Phenotype
Drug Therapy

Keywords

  • renal neoplasm
  • solitary fibrous tumor, BCOR
  • translocation

ASJC Scopus subject areas

  • Anatomy
  • Surgery
  • Pathology and Forensic Medicine

Cite this

BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors : A Close Mimic of Clear Cell Sarcoma of Kidney. / Argani, Pedram; Kao, Yu-Chien; Zhang, Lei; Sung, Yun Shao; Alaggio, Rita; Swanson, David; Matoso, Andres; Dickson, Brendan C.; Antonescu, Cristina R.

In: American Journal of Surgical Pathology, 01.01.2019.

Research output: Contribution to journalArticle

Argani, Pedram ; Kao, Yu-Chien ; Zhang, Lei ; Sung, Yun Shao ; Alaggio, Rita ; Swanson, David ; Matoso, Andres ; Dickson, Brendan C. ; Antonescu, Cristina R. / BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors : A Close Mimic of Clear Cell Sarcoma of Kidney. In: American Journal of Surgical Pathology. 2019.
@article{4f3f0324e7db46c497714bb900110da3,
title = "BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors: A Close Mimic of Clear Cell Sarcoma of Kidney",
abstract = "BCOR immunoreactivity is a sensitive and highly specific marker for clear cell sarcoma of the kidney (CCSK). However, a subset of adult renal sarcomas which overexpress BCOR are negative for BCOR genetic alterations, including BCOR gene fusions or BCOR-internal tandem duplication, and thus remain unclassified. We report 5 such undifferentiated renal/perirenal sarcomas which raised the differential diagnosis of CCSK due to their morphologic appearance and strong BCOR immunoreactivity, but which on RNA sequencing proved to be malignant solitary fibrous tumors (SFTs). The neoplasms occurred in patients at an age range of 30 to 62 years. Three patients were females and 2 male. Four were primary renal neoplasms while one was perirenal. All 5 neoplasms were cellular, nonpleomorphic, undifferentiated sarcomas with branching capillary vasculature composed of primitive round to ovoid neoplastic cells with scant cytoplasm and nuclei having fine, evenly dispersed chromatin. None of the cases demonstrated the typical hyperchromatic fusiform nuclei, prominent collagen deposition, or hemangiopericytomatous vasculature of SFT. All 5 cases were strongly immunoreactive for BCOR. Three cases were CD34 negative, where the other 2 were only focally CD34 positive. STAT6 was subsequently found to be positive by immunohistochemistry in all 5 cases. In summary, we report a previously unrecognized mimic of CCSK: malignant SFTs with an undifferentiated/small round cell phenotype along with branching capillary vasculature, strong immunoreactivity for BCOR, and minimal or no immunoreactivity for CD34. As CCSK is treated with a specific chemotherapy regimen, this distinction has therapeutic implications.",
keywords = "renal neoplasm, solitary fibrous tumor, BCOR, translocation",
author = "Pedram Argani and Yu-Chien Kao and Lei Zhang and Sung, {Yun Shao} and Rita Alaggio and David Swanson and Andres Matoso and Dickson, {Brendan C.} and Antonescu, {Cristina R.}",
year = "2019",
month = "1",
day = "1",
doi = "10.1097/PAS.0000000000001243",
language = "English",
journal = "American Journal of Surgical Pathology",
issn = "0147-5185",
publisher = "Lippincott Williams and Wilkins",

}

TY - JOUR

T1 - BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors

T2 - A Close Mimic of Clear Cell Sarcoma of Kidney

AU - Argani, Pedram

AU - Kao, Yu-Chien

AU - Zhang, Lei

AU - Sung, Yun Shao

AU - Alaggio, Rita

AU - Swanson, David

AU - Matoso, Andres

AU - Dickson, Brendan C.

AU - Antonescu, Cristina R.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - BCOR immunoreactivity is a sensitive and highly specific marker for clear cell sarcoma of the kidney (CCSK). However, a subset of adult renal sarcomas which overexpress BCOR are negative for BCOR genetic alterations, including BCOR gene fusions or BCOR-internal tandem duplication, and thus remain unclassified. We report 5 such undifferentiated renal/perirenal sarcomas which raised the differential diagnosis of CCSK due to their morphologic appearance and strong BCOR immunoreactivity, but which on RNA sequencing proved to be malignant solitary fibrous tumors (SFTs). The neoplasms occurred in patients at an age range of 30 to 62 years. Three patients were females and 2 male. Four were primary renal neoplasms while one was perirenal. All 5 neoplasms were cellular, nonpleomorphic, undifferentiated sarcomas with branching capillary vasculature composed of primitive round to ovoid neoplastic cells with scant cytoplasm and nuclei having fine, evenly dispersed chromatin. None of the cases demonstrated the typical hyperchromatic fusiform nuclei, prominent collagen deposition, or hemangiopericytomatous vasculature of SFT. All 5 cases were strongly immunoreactive for BCOR. Three cases were CD34 negative, where the other 2 were only focally CD34 positive. STAT6 was subsequently found to be positive by immunohistochemistry in all 5 cases. In summary, we report a previously unrecognized mimic of CCSK: malignant SFTs with an undifferentiated/small round cell phenotype along with branching capillary vasculature, strong immunoreactivity for BCOR, and minimal or no immunoreactivity for CD34. As CCSK is treated with a specific chemotherapy regimen, this distinction has therapeutic implications.

AB - BCOR immunoreactivity is a sensitive and highly specific marker for clear cell sarcoma of the kidney (CCSK). However, a subset of adult renal sarcomas which overexpress BCOR are negative for BCOR genetic alterations, including BCOR gene fusions or BCOR-internal tandem duplication, and thus remain unclassified. We report 5 such undifferentiated renal/perirenal sarcomas which raised the differential diagnosis of CCSK due to their morphologic appearance and strong BCOR immunoreactivity, but which on RNA sequencing proved to be malignant solitary fibrous tumors (SFTs). The neoplasms occurred in patients at an age range of 30 to 62 years. Three patients were females and 2 male. Four were primary renal neoplasms while one was perirenal. All 5 neoplasms were cellular, nonpleomorphic, undifferentiated sarcomas with branching capillary vasculature composed of primitive round to ovoid neoplastic cells with scant cytoplasm and nuclei having fine, evenly dispersed chromatin. None of the cases demonstrated the typical hyperchromatic fusiform nuclei, prominent collagen deposition, or hemangiopericytomatous vasculature of SFT. All 5 cases were strongly immunoreactive for BCOR. Three cases were CD34 negative, where the other 2 were only focally CD34 positive. STAT6 was subsequently found to be positive by immunohistochemistry in all 5 cases. In summary, we report a previously unrecognized mimic of CCSK: malignant SFTs with an undifferentiated/small round cell phenotype along with branching capillary vasculature, strong immunoreactivity for BCOR, and minimal or no immunoreactivity for CD34. As CCSK is treated with a specific chemotherapy regimen, this distinction has therapeutic implications.

KW - renal neoplasm

KW - solitary fibrous tumor, BCOR

KW - translocation

UR - http://www.scopus.com/inward/record.url?scp=85062847123&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85062847123&partnerID=8YFLogxK

U2 - 10.1097/PAS.0000000000001243

DO - 10.1097/PAS.0000000000001243

M3 - Article

AN - SCOPUS:85062847123

JO - American Journal of Surgical Pathology

JF - American Journal of Surgical Pathology

SN - 0147-5185

ER -