. Author manuscript; available in PMC: 2020 Mar 1.

Published in final edited form as: J Thorac Oncol. 2018 Dec 18;14(3):377–407. doi: 10.1016/j.jtho.2018.12.005

Table 7.

Specific sarcomas which mimic sarcomatoid carcinoma of the lung in thoracic regions

Clinical context	Sarcoma	Keratin expression^*	IHC markers	References
Primary	Malignant solitary fibrous tumor	+/−	STAT6, CD34, BCL6	^199–203
	Inflammatory Myofibroblastic tumor	+/−	ALK, SMA, FISH for ALK, ROS1, RET, NTRK3 fusions	^204–206
	Primary pleural synovial sarcoma	+/−	TLE1, focal keratins, FISH for SSI8 fusions	²⁰⁷
Metastatic	Uterine leiomyosarcoma	+/−	SMA, ER, desmin
	De-differentiated liposarcoma	−	CDK4, MDM2
	Malignant peripheral nerve sheath tumor	−	SOX 10, S100, H3K27me3 loss
	Malignant melanoma	−	SOX 10, Melan A, HMB45, SI00

usually focal and weak, but diffuse positive reactions can occur