bims-myxlip Biomed News
on Myxoid liposarcoma
Issue of 2026–05–24
two papers selected by
Laura Mannarino, Humanitas Research
  1. Durable remission of metastatic myxoid liposarcoma following the cautious addition of pembrolizumab to ongoing pazopanib treatment: A case report.
  2. MDM2 and DDIT3 coexpression in dedifferentiated liposarcoma with myxoid features: a retrospective cohort study.
  1. Rare Tumors. 2026 ;18 20363613261450115
    Durable remission of metastatic myxoid liposarcoma following the cautious addition of pembrolizumab to ongoing pazopanib treatment: A case report.
    Hussain Abbas, Wolfram Samlowski, Amin Hedayat.
      Responses to conventional treatments, like chemotherapy and targeted agents, are generally infrequent, and of brief duration in patients with metastatic soft tissue sarcomas. We present a case of metastatic myxoid liposarcoma that achieved biopsy-proven complete remission with minimal toxicity following the addition of pembrolizumab to pazopanib as fourth-line treatment. This regimen resulted in significant tumor regression following just five doses. After 15 doses of pembrolizumab, radiographs demonstrated an ongoing response, with stable residual lesions, and a biopsy of a sacral lesion confirmed a pathologic complete remission. The patient subsequently discontinued all therapies and remains in an ongoing unmaintained remission. The combination of pembrolizumab and pazopanib demonstrated unexpected clinical benefit with minimal toxicity, suggesting that it may be worthy of further investigation in myxoid liposarcoma and possibly other histologic subtypes of STS.
    Keywords:  checkpoint inhibitors; immunotherapy; sarcoma; targeted therapy; vascular endothelial growth factor receptor
    DOI:  https://doi.org/10.1177/20363613261450115
  2. Sci Rep. 2026 May 18.
    MDM2 and DDIT3 coexpression in dedifferentiated liposarcoma with myxoid features: a retrospective cohort study.
    Kivilcim Eren Ates, Gulfiliz Gonlusen, Seyda Erdogan, Akif Mirioglu.
      Dedifferentiated liposarcoma (DDLPS) can exhibit myxoid morphology that closely mimics myxoid liposarcoma (MLPS), creating significant diagnostic challenges. DDIT3 immunohistochemistry (IHC), a specific marker for MLPS, has been reported in a subset of DDLPS cases, but its frequency, staining pattern, and clinical significance remain poorly characterised. We retrospectively analysed 46 DDLPS cases with prominent myxoid features (≥ 10% myxoid component) confirmed by MDM2 IHC and fluorescence in situ hybridisation (FISH), treated at a single tertiary centre between January 2007 and January 2026. DDIT3 IHC was scored using a semiquantitative H-score system. DDIT3 positivity occurred in 11 of 46 cases (23.9%, 95% CI: 12.6-38.8%), predominantly as focal staining (9/11, 81.8%). All DDIT3-positive cases exhibited myxoid components comprising > 25% of tumour volume, versus variable myxoid extent in DDIT3-negative cases (p < 0.001). Mean H-score in DDIT3-positive cases was 48.6 ± 32.4 (range 15-120), significantly lower than in true MLPS controls (mean 278 ± 22, p < 0.001). Tumour size > 15 cm significantly increased the risk of local recurrence (risk ratio [RR] = 2.31, 95% CI: 1.02-5.24, p = 0.048). DDIT3 expression showed no significant association with local recurrence (p = 0.337), distant metastasis (p = 0.825), or mortality (p = 0.805). Kaplan-Meier analysis revealed no significant difference in overall survival (log-rank p = 0.782) or recurrence-free survival (log-rank p = 0.614) between DDIT3-positive and DDIT3-negative groups. DDIT3 positivity in DDLPS with myxoid features predominantly produces focal, low-intensity staining that distinguishes it from true MLPS. DDIT3 expression reflects chromosomal co-amplification within the 12q13-15 amplicon and lacks prognostic significance. Combined MDM2 and DDIT3 IHC with careful morphological assessment aids differential diagnosis, particularly when molecular testing is unavailable.
    Keywords:   DDIT3 ; MDM2 ; Dedifferentiated liposarcoma; Differential diagnosis; Immunohistochemistry; Myxoid features; Prognosis
    DOI:  https://doi.org/10.1038/s41598-026-53766-z
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