皮下：孤立性纤维瘤？讨论病例【91360.软组织743】

刘伟

一公里生命
病例(形态)分享第482例
3.0 cm subcutaneous mass; longstanding; recently enlarging.



一公里生命
CD34


神奇的东方树叶
PAX7核表达（G. Charville博士提供）

一公里生命
这例不横不尤
特殊形态的的“常见”肿瘤



任俊奇
@赵小辉  江苏大学附属医院 
SFT

一公里生命
STAT6


神奇的东方树叶
伴“隆突”样结构的富于细胞SFT


任俊奇
细胞微胖，差异性大于DFSP，圈起来的仍可见胶原
Patternless
无序结构，海豚样淡染胞核
见过SFT  CK较弥漫强阳性


一公里生命
Spindle cell neoplasm with a storiform pattern. Pale eosinophilic cytoplasm. Ovoid nuclei with mild 'random' atypia; inconspicuous mitotic activity. Subtle 'HPC-like' vasculature. At least partially circumscribed with a fibrous pseudocapsule. Diffuse staining for CD34. DDx:
Conventional dermatofibrosarcoma protuberans
- Typically dermal, with at least focal 'honeycomb' pattern
- Spindle-ovoid cells with storiform pattern
- Monomorphic nuclei; low mitotic activity
- Nondescript vasculature
- CD34 is typically diffusely positive
Deep fibrous histiocytoma :
- Typically subcutis, & circumscribed
- Spindle-ovoid cells with storiform pattern
- Nuclei with 'random' mild atypia; variable mitotic activity - Branching 'HPC-like' (~ 50%); variable inflammation
- CD34 is often positive
Solitary fibrous tumour :
- May be superficial; typically circumscribed
- Usually cellular, with 'irregular' pattern
- Bland nuclei; low mitotic activity
- 'HPC-like' vessels common; variable intercellular collagen - CD34 is usually positive
There is tremendous architectural, cytologic & immunohistochemical overlap within differential diagnosis. As a result, definitive classification is challenging without the benefit of ancillary testing:


一公里生命
In this case the tumour was diffusely positive for STAT6 (NGS confirmed NAB2-STAT6 fusion product), in keeping with SOLITARY FIBROUS TUMOUR.
注：病例来自网络，版权归原作者仅供学习