Anlotinib combined with chemotherapy in metastatic desmoplastic small round cell tumor: a case report

Background Desmoplastic small round cell tumor (DSRCT), a rare and highly aggressive sarcoma with predilection for adolescents, diagnosed through histopathology, immunohistochemistry, and cytogenetic studies to confirm its variable phenotypic expression and characteristic chromosomal translocation. Anlotinib is an orally administered multi-target tyrosine kinase inhibitor with anti-angiogenic and anti-proliferative properties. This case report describes a sustained objective response to chemotherapy combined with anlotinib in a young man with DSRCT, suggesting potential clinical activity for this aggressive sarcoma subtype. Case description A 23-year-old male presented with a 3-month history of a progressively enlarging right lower abdominal mass accompanied by localized tenderness. Diagnostic workup revealed multifocal peritoneal masses with retroperitoneal and thoracic lymphadenopathy on imaging. 18F-FDG PET/CT revealed hypermetabolic lesions involving the ileocecal junction, retroperitoneal lymph nodes, thoracic vertebrae, and pleura, confirming extensive multiorgan metastases involving the peritoneum, retroperitoneal and thoracic lymph nodes, pleura, and thoracolumbar vertebrae. Histopathology demonstrated classic small round cells within desmoplastic stroma, with immunohistochemical co-expression of epithelial (CK/EMA), mesenchymal (vimentin), and myogenic markers (paranuclear desmin+). Molecular confirmation of the EWSR1-WT1 fusion via Next-generation sequencing (NGS) established definitive diagnosis. Treatment involved a multidisciplinary strategy combining systemic therapy with VEC/IE (vincristine/epirubicin/cyclophosphamide alternating with ifosfamide/etoposide) chemotherapy and anlotinib. Ultimately, the patient had completed 8 cycles of chemotherapy combined with anlotinib, followed by anlotinib maintenance therapy, achieving a progression-free survival (PFS) of 17 months. Conclusion This case suggests potential clinical activity of anlotinib-based multimodal therapy in metastatic DSRCT and advocates the integration of immunohistochemistry with molecular detection of EWSR1-WT1 fusion for diagnostic precision, guiding biologically rational treatment paradigms.