RESUMO
Myelodysplastic Neoplasms (MDS) have been traditionally studied through the assessment of blood counts, cytogenetics, and morphology. In recent years, the introduction of molecular assays has improved our ability to diagnose MDS. The role of Measurable (minimal) Residual Disease (MRD) in MDS is evolving, and molecular and flow cytometry techniques have been used in several studies. In this review, we will highlight the evolving concept of MRD in MDS, outline the various techniques utilized, and provide an overview of the studies reporting MRD and the correlation with outcomes.
RESUMO
INTRODUCTION: Dedifferentiation occurs in approximately 10% of atypical lipomatous tumors/well-differentiated liposarcomas (ALT/WDLPS), primarily in retroperitoneal or deep-seated tumors, conferring metastatic potential. Superficial dedifferentiated liposarcoma (sDDLPS) is rare, and its progression and natural history are poorly documented. METHODS: We performed a 15-year retrospective review of our pathology database to identify cases of DDLPS in the skin or subcutaneous tissue. Diagnosis of primary sDDLPS required evidence of non-lipogenic sarcoma in the skin or subcutis, with concurrent ALT/WDLPS and/or MDM2 amplification. RESULTS: We identified 14 cases of DDLPS involving skin or subcutis: 7 primary sDDLPS and 7 secondary lesions (3 from recurrent deep DDLPS and 4 from metastasis). Primary sDDLPS cases (4 females, 3 males; median age: 74) mainly presented as undifferentiated spindle cell or pleomorphic sarcoma. Tumor grades were grade 2 (5 cases) and grade 3 (2 cases), with three cases also showing grade 1 areas. MDM2 amplification was confirmed in 6 sDDLPSs for which FISH was successfully performed. Follow-up available for 6 sDDLPS patients showed 2 local recurrences, treated with re-excision and radiation therapy, with all disease-free at last follow-up (5-126 months). Of the 7 secondary cases, 2 had ongoing disease after multiple recurrences, 1 was disease-free, and all 4 with cutaneous metastasis died of disease (follow-up range: 24-263 months). CONCLUSION: These findings emphasize the importance of distinguishing between primary sDDLPS and secondary lesions due to their distinct prognoses. Metastasis or superficial extensions from deep DDLP correlate with a considerably worse prognosis than those originating in superficial tissues.