Abstract：
BACKGROUND: 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).
CONCLUSIONS: 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.
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).
CONCLUSIONS: 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.
摘要：
背景：去分化发生在大约10％的非典型脂肪瘤/高分化脂肪肉瘤（ALT/WDLPS）中，主要在腹膜后或深部肿瘤中，赋予转移潜力。浅表去分化脂肪肉瘤（sDDLPS）是罕见的，它的发展和自然史记录很少。
方法：我们对我们的病理数据库进行了15年的回顾性审查，以确定皮肤或皮下组织中的DDLPS病例。原发性sDDLPS的诊断需要皮肤或皮下组织非脂源性肉瘤的证据，同时ALT/WDLPS和/或MDM2扩增。
结果：我们确定了14例涉及皮肤或皮下组织的DDLPS：7例原发性sDDLPS和7例继发性病变（3例来自复发性深DDLPS，4例来自转移）。原发性sDDLPS病例（4名女性，3名男性；中位年龄：74）主要表现为未分化的梭形细胞或多形性肉瘤。肿瘤分级为2级(5例)和3级(2例),三个案例也显示了一级地区。在6个sDDLPS中证实了MDM2扩增，已成功执行FISH。6例sDDLPS患者随访显示2例局部复发，再切除和放射治疗，在最后一次随访（5-126个月）时全部无病。在7个次要案例中，2在多次复发后患有持续疾病，1还活着，4例皮肤转移均死亡(随访24～263个月)。
结论：这些发现强调了区分原发性sDDLPS和继发性病变的重要性，因为它们的预后不同。深部DDLP的转移或浅表延伸与源自浅表组织的预后差很多。
方法：我们对我们的病理数据库进行了15年的回顾性审查，以确定皮肤或皮下组织中的DDLPS病例。原发性sDDLPS的诊断需要皮肤或皮下组织非脂源性肉瘤的证据，同时ALT/WDLPS和/或MDM2扩增。
结果：我们确定了14例涉及皮肤或皮下组织的DDLPS：7例原发性sDDLPS和7例继发性病变（3例来自复发性深DDLPS，4例来自转移）。原发性sDDLPS病例（4名女性，3名男性；中位年龄：74）主要表现为未分化的梭形细胞或多形性肉瘤。肿瘤分级为2级(5例)和3级(2例),三个案例也显示了一级地区。在6个sDDLPS中证实了MDM2扩增，已成功执行FISH。6例sDDLPS患者随访显示2例局部复发，再切除和放射治疗，在最后一次随访（5-126个月）时全部无病。在7个次要案例中，2在多次复发后患有持续疾病，1还活着，4例皮肤转移均死亡(随访24～263个月)。
结论：这些发现强调了区分原发性sDDLPS和继发性病变的重要性，因为它们的预后不同。深部DDLP的转移或浅表延伸与源自浅表组织的预后差很多。
