Solitary fibrous tumour of the genitourinary tract: a clinicopathological study of 11 cases and their association with theNAB2-STAT6fusion gene

Abstract

Aims To characterise clinicopathological features and clinical outcomes of the genitourinary tract solitary fibrous tumours, incorporating NAB2-STAT6 gene fusion status. Methods The presence of the molecular hallmark NAB2-STAT6 gene fusion and for the defining fusion partner product STAT6 was assessed in 11 cases of the genitourinary tract solitary fibrous tumours. NAB2-STAT6 gene fusion analysis was performed using a break-apart fluorescence in situ hybridisation (FISH) probe using a probe cocktail with Bacterial artificial chromosome (BAC) clones for STAT6 and NAB2. Results Eleven solitary fibrous tumours were diagnosed in eight male patients and three female patients with a mean age of 46 years (range: 11-64 years). Four of the tumours had malignant histological features, and three were considered moderate risk for metastasis. With a mean follow-up time of 61 months, 1 recurred locally and 2 presented at distant metastatic sites. Using a breakapart FISH probe cocktail, we found the NAB2-STAT6 gene fusion and nuclear STAT6 expression in 58% and 91% of cases, respectively. However, the NAB2-STAT6 fusion status was not correlated with STAT6 expression or useful in discriminating between malignant histological features or subsequent clinical outcomes in the genitourinary solitary fibrous tumours. Conclusions A subset of solitary fibrous tumours of the genitourinary tract behaved aggressively. Using a breakapart FISH probe cocktail, we found the NAB2-STAT6 gene fusion in 64% of cases. However, the NAB2-STAT6 fusion status was not correlated with STAT6 expression or useful in discriminating between low-risk or high-risk tumours and subsequent clinical outcomes.

Solitary fibrous tumor

“…These fusions have been demonstrated by polymerase chain reaction to be present in 91% of SFT, with absence of this function in potentially histologically similar appearing tumors (44). This fusion may also be detected by a break-apart fluorescent in situ hybridization probe, seen in 58% of cases in one study (45). This did not, however, correlate with patient outcome.…”

Malignant Solitary Fibrous Tumor of the Renal Vein Presenting as a Giant Renal Artery Aneurysm: A Case Report and Review of Literature

“…Until this report, however, there has never been a SFT originating from the renal vein. [2][3][4][5] This report is not only remarkable for its description of a new origination of SFT, but also its presentation as a giant RAA is unique. RAA is an uncommon finding (incidence <1%) and usually asymptomatic at the time of discovery.…”

“…1 These have rarely been noted in the literature to originate from major blood vessels. [2][3][4][5] Giant renal artery aneurysm (RAA) is an uncommon condition with less than 30 cases reported in the literature. They are notable for their large size and proclivity to rupture.…”

BCOR Overexpression in Renal Malignant Solitary Fibrous Tumors

“…The clinicopathologic features of renal SFT have generally paralleled their extrarenal counterparts. Most renal SFT have been classified as benign and appear to follow an uneventful clinical course, though rare benign-appearing tumors have metastasized [30][31][32][33] . Approximately 15 cases of malignant renal SFT have been reported, of which approximately half have either recurred or metastasized in limited follow-up.…”