In:
Histopathology, Wiley, Vol. 68, No. 4 ( 2016-03), p. 492-501
Abstract:
Solitary fibrous tumour ( SFT ) harbours recurrent inv12(q13q13)‐derived NAB 2 – STAT 6 fusions, resulting in STAT 6 nuclear expression. SFT s affecting the head and neck are rare, for which we reported their clinicopathological, immunohistochemical, and genetic features. Methods and results With 19 cases assessable for NAB 2 – STAT 6 fusions, 36 head and neck SFT s (18 males; 18 females) diagnosed between 13 and 79 years (median, 47 years) of age were analysed for clinicopathological features and STAT 6 immunoexpression. These SFT s, ranging from 5 to 80 mm (median, 25 mm), affected the oral cavity/pharynx (12), orbit (11), sinonasal structures (seven), and somatic soft tissues or skull (six). Histologically, 20 SFT s were conventional, six were giant‐cell angiofibroma‐like, one was fat‐forming, four were cellular/atypical, and five were malignant (two developing metastases). STAT 6 distinctively decorated the tumoral nuclei in 35 (97.2%) SFT s, but not in 29 site‐relevant histological mimics categorized into 12 entities. Sixteen (84.2%) SFT s showed NAB 2– STAT 6 fusions with highly heterogeneous exon compositions, including NAB 2 ex6– STAT 6 ex17 in four cases, NAB 2 ex4– STAT 6 ex2 in three cases, NAB 2 ex2– STAT 6 ex2, NAB 2 ex4– STAT 6 ex4, NAB 2 ex6– STAT 6 ex16 and NAB 2 ex6– STAT 6 ex18 in two cases each, and NAB 2 ex3– STAT 6 ex19 in one case. Conclusions Nuclear STAT 6 immunoexpression is sensitive and specific for distinguishing SFT from mimics. However, considerable heterogeneity exists in the head and neck SFT s regarding the locations, histological patterns, and NAB 2– STAT 6 fusion variants.
Type of Medium:
Online Resource
ISSN:
0309-0167
,
1365-2559
DOI:
10.1111/his.2016.68.issue-4
Language:
English
Publisher:
Wiley
Publication Date:
2016
detail.hit.zdb_id:
2006447-0
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