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目的 探讨原发性腹膜后及肠系膜脂肪肉瘤的外科治疗方法。方法 回顾性分析1993～2001年收治的18例原发性腹膜后及肠系膜脂肪肉瘤病人经手术治疗27例次的临床资料。结果 脂肪肉瘤占同期经手术探查的原发性腹膜后及肠系膜实体瘤的31．6％(18／57)；临床表现主要为进行性增大的腹部包块与消化道症状：病理类型以高分化型多见(13／18)；首诊后16例获得临床根治性切除，6例复发性脂肪肉瘤病人，共接受15次手术；全组合并单侧肾切除6例，部分结肠切除4例，部分空肠切除和胃大部切除各1例；肠系膜脂肪肉瘤手术多采用完整切除术(8／10)。结论 手术切除是目前唯一有效的治疗方法，必要时可行联合脏器切除术，但不应强求根治；为改善生存质量、延长生存期，对多发肿瘤不能完整切除者应积极实施姑息性减瘤术，多次复发者有条件可多次手术；采用完整切除术、尽量避免肠切除治疗对多发性及复发性肠系膜脂肪肉瘤具有重要临床价值。     

Lipoblastoma and lipoblastomatosis in infancy and childhood: histopathologic, ultrastructural, and cytogenetic features

Lipoblastoma is a relatively rare tumor that occurs in infancy and early childhood and arises from embryonic white fat. Although a benign tumor, lipoblastomas tend to recur and may resemble myxoid liposarcoma. The authors report 26 cases over a 15-year period at Texas Children's Hospital. There was a slight female predilection (14F:12M). The most common symptom was a painless mass with or without increasing size. The trunk, extremities, head and neck, retroperitoneum, inguinal canal, peritoneal cavity, and lung were the tumor sites. Most tumors were circumscribed lipoblastomas and the minority were diffuse infiltrative lipoblastomatosis. Reexcision for residual or recurrent tumor was necessary more frequently in patients with lipoblastomatosis. Histopathologic examination and ultrastructural examination revealed cellular neoplasms composed of immature adipocytes with relatively well-defined septa, frequent lipoblasts, a fine vascular network, and often a myxoid appearance resembling myxoid liposarcoma. Cytogenetics was performed in 4 cases with chromosome 8q abnormality being most common. The major concern with lipoblastoma in children is to completely excise the tumor to avoid leaving residual tumor and to prevent recurrences. Confusion with myxoid liposarcoma, well-differentiated liposarcoma, and typical lipomas may occur. Although asymptomatic, lipoblastomas may cause dysfunction of other organ systems due to mass effect. Complete surgical excision with at least 2 years of follow-up is the preferred therapy.     

Transoral laser resection of hypopharyngeal liposarcoma

Liposarcomas are rare malignant tumours of the connective tissue. Microscopically they resemble lipomas. They are usually found on the limbs or trunk. Fewer than 40 cases of hypopharyngeal liposarcoma have been reported in the literature. Surgical excision with a cervical or endoscopic approach has been the first-line treatment for these cases. We present a patient with the first documented primary excision via carbon dioxide laser using an entirely transoral approach. This case suggests a new standard of management but also highlights the difficulties with investigation and diagnosis in a rare presentation.     

下肢高分化及黏液型脂肪肉瘤的影像表现与病理分析

目的探讨下肢高分化及黏液型脂肪肉瘤影像学表现与病理学的关系,提高影像诊断准确率。方法回顾分析12例下肢脂肪肉瘤的影像学表现,与术后病理类型进行对照分析。结果8例高分化型脂肪肉瘤边界清楚,T,WI及T2WI呈高或稍高信号,内部分隔厚度〉2mm;CT为均匀低密度,分隔轻中度强化。病理见较多分化好的脂肪细胞。4例黏液型边界大部分清楚,T,WI等低信号,3例夹杂少许高信号脂肪影,T2WI以高信号为主,内见多房分隔：CT上呈等、低混杂密度,不均匀团片样、云絮状强化,实性成分及粗大间隔强化明显。病理上疏散黏液中见短梭形细胞或单泡状脂母细胞。结论高分化型脂肪肉瘤影像学表现典型,多数黏液型脂肪肉瘤伴有少量脂肪,MRI及CT在一定程度上能反映肿瘤的分化程度。     

腹膜后伴有异源性分化的去分化脂肪肉瘤病例分析及文献复习

目的：探讨腹膜后伴有异源性横纹肌肉瘤和神经内分泌分化的去分化脂肪肉瘤分子遗传学特征、临床病理特点、诊断和鉴别诊断。方法回顾性分析1例伴有异源性横纹肌肉瘤和神经内分泌分化的去分化脂肪肉瘤临床病理过程、免疫组织化学、组织形态学特点、诊断,并结合文献复习。结果光镜下肿瘤由两种不同分化成分和形态结构组成,分化成分为分化良好的脂肪瘤样脂肪肉瘤及炎症性、黄色肉芽肿性成分;去分化成分为高度恶性的多形性未分化肉瘤及低度恶性的侵袭性纤维瘤病和黏液纤维肉瘤样成分。去分化成分中可见异源性横纹肌肉瘤及神经内分泌分化。免疫组化：Viment （＋）;CD68（＋）;CDK4（＋）;FLi-1（＋）;MyOD1（＋）;Myogenin（＋）;NSE （＋）;CD56（＋）;CgA （＋/-）;Syn （＋/-）;Bcl-2（＋）;S-100（＋/-）;CD99（＋/-）;Desim（＋）;CD34（-）;LCA（-）;MDM2（-）;CK-AE1/AE3（-）;Ki-67阳性增殖指数＞60％。结论发生在腹膜后的巨大肿瘤,在同一肿瘤内存在两种不同分化成分和形态结构,并伴有异源性成分分化,其复杂性、多形性常造成诊断困难。因此,掌握临床病理及免疫组化特点对该病的诊断和鉴别诊断具有重要意义。     

Lipomatous tumours of soft tissues: an update

This review summarizes the clinicopathological features of recently characterized variants of lipomatous tumours of soft tissue, attempts to deal with some difficult conceptual issues relating to adipocytic neoplasms and aims to provide an update on cytogenetic aspects of fatty tumours. Myolipoma is a rare benign neoplasm, occurring most frequently in adults in the deep soft tissue of the abdomen or retroperitoneum, and is composed of irregularly admixed mature adipose and smooth muscle tissues. Chondroid lipoma represents an unusual benign lesion occurring mainly in adult females subcutaneously or in deep soft tissue; it is easily mistaken for myxoid liposarcoma or extraskeletal myxoid chondrosarcoma. Spindle-cell liposarcoma is a variant of well-differentiated liposarcoma quite commonly found in subcutaneous tissue of the shoulder region and upper limbs and is composed of relatively bland-appearing spindle cells mixed with a well-differentiated liposarcomatous component. Recently there has been considerable debate about classification of lipomatous tumours. The term atypical lipoma was proposed for a group of well-differentiated non-metastasizing liposarcomas arising in surgically amenable soft tissues and for deep-seated atypical adipocytic neoplasms that show variation in adipocytic size and atypical stromal cells but lack lipoblasts. However, these neoplasms recur repeatedly and may dedifferentiate and thereby acquire metastatic potential. We use the diagnosis atypical lipoma with caution and propose to use the terms well-differentiated liposarcoma and atypical lipoma interchangeably. The relationship between myxoid and round-cell liposarcoma, which constitutes the morphological spectrum of a single entity, has been clarified but there remain considerable problems in defining likely clinical behaviour. The recent advances in cytogenetic characterization and classification of lipomatous tumours, which is already proving to be of diagnostic importance, are reviewed, and the genetic importance of the distinct chromosomal translocation in myxoid/round cell liposarcoma is briefly discussed.     

Lipoblastoma and Lipoblastomatosis in Infancy and Childhood: Histopathologic,Ultrastructural, and Cytogenetic Features

Lipoblastoma is a relatively rare tumor that occurs in infancy and early childhood and arises from embryonic white fat. Although a benign tumor, lipoblastomas tend to recur and may resemble myxoid liposarcoma. The authors report 26 cases over a 15-year period at Texas Children's Hospital. There was a slight female predilection (14F:12M). The most common symptom was a painless mass with or without increasing size. The trunk, extremities, head and neck, retroperitoneum, inguinal canal, peritoneal cavity, and lung were the tumor sites. Most tumors were circumscribed lipoblastomas and the minority were diffuse infiltrative lipoblastomatosis. Reexcision for residual or recurrent tumor was necessary more frequently in patients with lipoblastomatosis. Histopathologic examination and ultrastructural examination revealed cellular neoplasms composed of immature adipocytes with relatively well-defined septa, frequent lipoblasts, a fine vascular network, and often a myxoid appearance resembling myxoid liposarcoma. Cytogenetics was performed in 4 cases with chromosome 8q abnormality being most common. The major concern with lipoblastoma in children is to completely excise the tumor to avoid leaving residual tumor and to prevent recurrences. Confusion with myxoid liposarcoma, well-differentiated liposarcoma, and typical lipomas may occur. Although asymptomatic, lipoblastomas may cause dysfunction of other organ systems due to mass effect. Complete surgical excision with at least 2 years of follow-up is the preferred therapy.     

Incidental lipoma-like hibernoma arising from the adrenal gland: A well-differentiated liposarcoma mimicker

Hibernomas are uncommon benign lipomatous tumors which show differentiation toward brown fat. To our knowledge, only one case of adrenal hibernoma has been previously reported. We describe a 55-year-old woman showing an incidental, 1.7 cm-hibernoma associated with a 2.6 cm-cortical adenoma producing primary hyperaldosteronism (Conn's syndrome), both in the left adrenal gland. The hibernoma was composed predominantly of univacuolated mature fat cells admixed with small vessels. Scattered areas composed of large multivacuolated pale cells with central or paracentral nuclei, mimicking lipoblasts, accounting for less than 30% of the tumor, were found. These cells lacked nuclear hyperchromasia or marked atypia, were S100-positive, and showed numerous mitochondria reactive with the anti-mitochondrial antibody. A diagnosis of lipoma-like hibernoma was made. Pathologists should be aware of this variant of hibernoma to avoid misdiagnosis and excessive treatment.     

Pancreas-Sparing Duodenectomy for a Recurrent Retroperitoneal Liposarcoma: Report of a Case

Pancreas-sparing duodenectomy (PSD), which allows preservation of the pancreas in its entirety, is a promising procedure for low-grade malignancies of the duodenum, the periampullary region, and the neighboring retroperitoneum. We report a case of recurrent retroperitoneal liposarcoma involving the second and third parts of the duodenum, which was extirpated using PSD, after a right hemicolectomy for tumor invasion of part of the colonic hepatic flexura. The Roux-en-Y jejunal limb was sutured to the duodenal bulb in an end-to-end fashion, and the biliary and pancreatic duct systems were reconstructed with end-to-side anastomoses, placing the jejunal limb distal to the bulbo-jejunostomy after a septoplasty to repair the adjacent pancreatic and biliary ducts. Because retroperitoneal liposarcoma has a low incidence of lymph node metastasis, pancreaticoduodenectomy may be inappropriate, especially if minimally extensive surgery can ensure organ preservation. Pancreas-sparing duodenectomy could be the most appropriate procedure for nonepithelial malignant tumors located around the duodenum distal to the pylorus, which have no involvement with the pancreatic parenchyma or periduodenal lymph nodes.