Pediatric Non-Myofibroblastic Primitive Spindle Cell Tumors with ALK Gene Rearrangements and Response to Crizotinib. (September 2022)

• Record Type: Journal Article
• Authors: Rakheja, Dinesh; Park, Jason Y.; Fernandes, Neil J.; Watt, Tanya C.; Laetsch, Theodore W.; Collins, Rebecca R. J.
• Is Part Of: International journal of surgical pathology. Volume 30:Number 6(2022)
• Page Start: 706
• Page End: 715
• Publication Date: 2022-09
• Subjects: ALK -- PLEKHH2 -- CLTC -- pediatric -- spindle cell tumor -- gene fusion -- RNA sequencing -- crizotinib; Pathology, Surgical -- Periodicals; 617.07
• DOI: 10.1177/10668969221080072
• Languages: English
• ISSNs: 1066-8969

Abstract

We describe two poorly differentiated, non-myofibroblastic (SMA−, S100+, CD34±), spindle cell neoplasms with immunohistochemical positivity for ALK and with ALK gene rearrangements leading to PLEKHH2::ALK and CLTC::ALK fusions, respectively. ALK protein overexpression and/or gene fusions should be evaluated in poorly differentiated spindle cell neoplasms, even when there is an absence of a myofibroblastic phenotype. A positive ALK evaluation has therapeutic implications as both tumors responded to single-agent treatment with the tyrosine kinase inhibitor crizotinib.