Pseudoendocrine sarcoma: clinicopathologic, molecular, and epigenetic features of one case

• Published in: Virchows Archiv : an international journal of pathology 2023-12, Vol.483 (6), p.899-904
• Main Authors: Vizcaino, M. Adelita, Folpe, Andrew L., Huffman, Henry, Panchal, Ripul R., Nielsen, G. Petur, Kipp, Benjamin R., Turakulov, Rust, Aldape, Kenneth, Giannini, Caterina
• Format: Article
• Language: English
• Subjects: Brief Report; Cancer research; Cancer therapies; Central nervous system; Chemoradiotherapy; Cloning; DNA methylation; Epigenetics; Ewings sarcoma; Genomes; Keratin; Medical research; Medicine; Medicine & Public Health; Morphology; Mutation; Neoplasia; Nervous system; Neuroendocrine tumors; Pathology; Sarcoma; Soft tissues; Synaptophysin; Tumors; β-Catenin
• ISSN: 0945-6317; 1432-2307
• DOI: 10.1007/s00428-023-03695-3

Pseudoendocrine sarcoma (PES) is a recently described neoplasm typically arising in paravertebral soft tissues. Histologically, PES resembles well-differentiated neuroendocrine tumors but lacks expression of epithelial/neuroendocrine markers, and most show aberrant nuclear β-catenin positivity. We describe the clinicopathological and molecular features and DNA methylation profile of one PES. A resected paraspinal soft tissue mass in a 52-year-old man showed a neuroendocrine-like neoplasm, negative for keratin, and synaptophysin and showing diffuse nuclear β-catenin expression. Targeted NGS confirmed a CTNNB1 (p.S37C) mutation. Whole genome methylation analysis showed no match to any methylation class in the central nervous system tumor (versions 11b6 and 12b6) or sarcoma classifier (calibrated scores of ≤0.3), but clustered together with a recently reported PES in which methylation analysis was also performed. He remained disease-free for 18 months after surgery, followed by chemoradiation. As more cases are examined, our findings suggest that PES may have a unique methylation profiling signature.