ABSTRACT
BACKGROUND: Challenging emerging entities with distinctive molecular signatures may benefit from algorithms for diagnostic work-up. METHODS: Fusion sarcomas (2020-2021, during pandemic) were diagnosed by clinicoradiology, morphology, phenotype, and next-generation sequencing (NGS). RESULTS: Six fusion sarcomas in two males and four females involved the chest-wall, neck, or extremities; ages ranged 2-73, median 18â¯years. Sizes ranged 5.3-25.0, median 9.1â¯cm. These include high grade 1) TPR-NTRK1 of proximal femur with a larger rounded soft tissue mass, previously considered osteosarcoma yet without convincing tumor matrix. A pathologic fracture necessitated emergency hemipelvectomy (NED) and 2) novel KANK1-NTRK2 sarcoma of bone and soft tissue with spindled pleomorphic to epithelioid features (AWD metastases). 3) Novel ERC1-ALK unaligned fusion, a low grade infiltrative deep soft tissue hand sarcoma with prominent-vascularity, myopericytoid/lipofibromatosis-like ovoid cells, and collagenized stroma, was successfully treated with ALK-inhibitor (Crizotinib), avoiding amputation. These NTRK and ALK tumors variably express S100 and CD34 and were negative for SOX10. 4) and 5) CIC-DUX4 round cell tumors (rapid metastases/demise), one with COVID superinfection, were previously treated as Ewing sarcoma. These demonstrated mild pleomorphism and necrosis, variable myxoid change and CD99 reactivity, and a distinctive dot-like-Golgi WT1 immunostaining pattern. 6) A chest wall/thoracic round cell sarcoma, focal CD34/ keratins/CK7, revealed nuclear-STAT6, STAT6-NAB2 by NGS, confirming malignant solitary fibrous tumor, intermediate-risk-stratification (AWD metastases). CONCLUSIONS: Recent fusion sarcomas include new KANK1-NTRK2 and ERC1-ALK, the latter successfully treated by targeted-therapy. ALK/NTRK fusion partners TPR and KANK1 suggest unusual high-grade morphology/behavior. Clinicoradiologic, morphologic, and phenotypic algorithms can prompt molecular-targeted immunostains or NGS for final classification and promising inhibitor therapy.
Subject(s)
Biomarkers, Tumor/genetics , Femoral Neoplasms/genetics , Gene Fusion , Head and Neck Neoplasms/genetics , Sarcoma/genetics , Soft Tissue Neoplasms/genetics , Thoracic Neoplasms/genetics , Adolescent , Adult , Aged , Algorithms , Antineoplastic Agents/therapeutic use , Child , Child, Preschool , Extremities/pathology , Female , Femoral Neoplasms/diagnosis , Femoral Neoplasms/drug therapy , Femoral Neoplasms/pathology , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/pathology , High-Throughput Nucleotide Sequencing , Humans , Male , Middle Aged , Neoplasm Grading , Phenotype , Prognosis , Sarcoma/diagnosis , Sarcoma/drug therapy , Sarcoma/pathology , Soft Tissue Neoplasms/diagnosis , Soft Tissue Neoplasms/drug therapy , Soft Tissue Neoplasms/pathology , Thoracic Neoplasms/diagnosis , Thoracic Neoplasms/drug therapy , Thoracic Neoplasms/pathology , Thoracic Wall/pathology , Young AdultABSTRACT
The coronavirus disease-2019 (COVID-19) pandemic is deeply impacting the accessibility of cancer patients to surgery. In resource-limited conditions, the standard of care might not be deliverable, but evidence to support alternative management strategies often exists. By revisiting available treatment options, this review provides surgical oncologists with an evidence-based framework for treating patients with gastrointestinal stromal tumor, extremity/truncal soft tissue sarcoma, and retroperitoneal sarcoma to rapidly adapt their decision-making to the constant evolution of the COVID-19 pandemic.