Solitary Fibrous Tumour of the Genitourinary Tract: A Clinicopathological Study of 11 Cases and Their Association with the NAB2-STAT6 Fusion Gene
Kouba E, Simper NB, Chen S, Williamson SR, Grignon DJ, Eble JN, MacLennan GT, Montironi R, Lopez-Beltran A, Osunkoya AO, Zhang S, Wang M, Wang L, Tran T, Emerson RE, Baldrige LA, Monn MF, Linos K, and Cheng L. Solitary fibrous tumour of the genitourinary tract: a clinicopathological study of 11 cases and their association with the NAB2-STAT6 fusion gene. J Clin Pathol 2016.
Journal of clinical pathology
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 break-apart 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 break-apart 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.
Medical Subject Headings
Adolescent; Adrenal Gland Neoplasms; Adult; Child; Disease Progression; Female; Gene Fusion; Humans; Male; Middle Aged; Repressor Proteins; STAT6 Transcription Factor; Solitary Fibrous Tumors; Urogenital Neoplasms; Young Adult