Posted: Friday, February 17, 2023
Cristina R. Antonescu, MD, of Memorial Sloan Kettering Cancer Center, New York, and colleagues studied the molecular and clinicopathologic characteristics of head and neck mesenchymal tumors harboring kinase fusions. Published in The American Journal of Surgical Pathology, the results of this study support molecular testing for various kinase fusions in these spindle cell neoplasms, as pan-TRK positivity is widely reported in the presence of NTRK fusions.
This study focused on 15 patients with head and neck mesenchymal tumors harboring kinase fusions. The median patient age was 13, and related kinase genes included NTRK1 (n = 6), NTRK3 (n = 5), BRAF (n = 2), MET, and RET (n = 1 each). The most common tumor location was intraosseous and skin (n = 4 each), followed by soft tissue of the face or neck, major salivary glands, sinonasal tract (n = 2 each), and oral cavity (n = 1).
Tumor histology ranged from benign to high-grade and were characterized as fibrosarcoma, malignant peripheral nerve sheath tumor–like, a novel phenotype resembling myxoma, and inflammatory myofibroblastic tumor–like. Common features of malignant peripheral nerve sheath tumor–like and lipofibromatosis-like neural tumors included staghorn vasculature and perivascular hyalinization or stromal keloid–like collagen bands.
Tumors classified as high-grade harbored an NTRK1 or BRAF arrangement (n = 1 each). S100 and CD34 immunopositivity was reported in 71% and 60% of all tumors, respectively, most frequently in malignant peripheral nerve sheath tumor–like and lipofibromatosis-like neural tumors. For NTRK-translocated tumors alone, pan-TRK was a sensitive marker; pan-TRK was negative in tumors with other kinase fusions. Overall, one patient with a high-grade tumor experienced distant metastasis.
Disclosure: The study authors reported no conflicts of interest.
The American Journal of Surgical Pathology