p63 immunohistochemical staining is limited in soft tissue tumors

p63 is a p53 homolog that is expressed in various normal epithelial tissues and epithelial malignancies. Its expression in mesenchymal lesions has not been examined in depth; therefore, we studied p63 expression by immunohistochemical analysis in 650 soft tissue tumors. We found that p63 expression is limited in soft tissue tumors. The majority of tumors studied were p63-, including all cases of angiosarcoma, lipomatous neoplasms, dermatofibrosarcoma protuberans, solitary fibrous tumor, schwannoma, neurofibroma, gastrointestinal stromal tumor, and leiomyosarcoma. Nuclear p63 reactivity was found in a subset of soft tissue myoepithelioma and myoepithelial carcinoma of soft tissue, cellular neurothekeoma, soft tissue perineurioma, Ewing sarcoma/peripheral neuroectodermal tumor, diffuse-type giant cell tumor, and giant cell tumor of soft parts. Infrequent, weak, or focal p63-staining patterns were observed in low-grade fibromyxoid sarcoma, malignant peripheral nerve sheath tumor, extraskeletal myxoid chondrosarcoma, myxofibrosarcoma, proximal-type epithelioid sarcoma, synovial sarcoma, embryonal rhabdomyosarcoma, desmoplastic small round cell tumor, atypical fibroxanthoma, and spindle cell melanoma. Absent p63 expression is typical for most soft tissue tumors, including most (but not all) that would be in the differential diagnosis of spindle cell squamous carcinoma.     

Gastric schwannoma: a clinicopathologic study of 51 cases and critical review of the literature

Schwannoma is a rare gastrointestinal mesenchymal tumor, as the vast majority of gastric mesenchymal tumors are gastrointestinal stromal tumors. In this study, we analyzed clinicopathologically 51 gastric schwannomas. These tumors predominantly occurred in older adults with a marked female predominance (40 women and 11 men; median and mean ages, 60 and 58 years). They variably presented with gastric discomfort, bleeding, or rarely gastric outlet obstruction; and many were incidental findings during other medical procedures. The tumors ranged from 1 to 10.5 cm (median, 4.5 cm). The typical histologic features included spindle cells usually with microtrabecular architecture and focal nuclear atypia, and peritumoral lymphoid cuff, whereas features of soft tissue schwannomas, such as encapsulation, nuclear palisading, vascular hyalinization, and dilatation, were absent or infrequent. Median mitotic count was 2/50 high-power fields, with the highest count being 13/50 high-power fields. No malignant variants were recognized, and long-term follow-up did not reveal recurrences or metastases. Immunohistochemically, all examined tumors were S100 protein positive and most were also GFAP positive, whereas CD34 and NF68 were encountered rarely and all tumors were negative for HMB45, KIT, DOG1/Ano 1, smooth muscle actin, desmin, and synaptophysin. None of the 9 tumors studied contained gastrointestinal stromal tumor-specific KIT or PDGFRA mutations. Fluorescence in situ hybridization studies revealed multiple signals with BCR probe (chromosome 22) and centromeric probes for chromosomes 2 and 18 suggesting polyploidy. These findings indicate that gastric schwannoma is a distinctive form of peripheral nerve sheath tumor that in many ways differs from soft tissue schwannoma. It should be distinguished from gastrointestinal stromal tumor and other mesenchymal tumors of the gastrointestinal tract, such as the S100 protein-positive gastrointestinal clear cell sarcoma and metastatic melanoma.     

Cluster analysis of immunohistochemical profiles in synovial sarcoma, malignant peripheral nerve sheath tumor, and Ewing sarcoma.

As a result of overlapping morphologic and immunohistochemical features, it can be difficult to distinguish synovial sarcoma, malignant peripheral nerve sheath tumor, and Ewing sarcoma/primitive neuroectodermal tumor in core biopsies. To analyze and compare immunohistochemical profiles, we stained tissue microarrays of 23 synovial sarcomas, 23 malignant peripheral nerve sheath tumors, and 27 Ewing sarcomas with 22 antibodies potentially useful in the differential diagnosis, and analyzed the data with cluster analysis. Stain intensity was scored as none, weak, or strong. For CD99, tumors with membranous accentuation were independently categorized. Cluster analysis sorted five groups, with like tumors clustering together. Synovial sarcoma clustered into two groups: one cytokeratin and EMA positive (n = 11), the other mostly cytokeratin negative, EMA positive, bcl-2 positive and mostly CD56 positive (n = 9). Malignant peripheral nerve sheath tumor clustered into two groups: one S100 positive, with nestin and NGFR positivity in most (n = 10), the other mostly S100 negative, and variably but mostly weakly positive for nestin and NGFR (n = 11). Ewing sarcomas clustered into a single group driven by membranous CD99 staining. Thirteen cases failed to cluster (outliers), while three Ewing sarcomas clustered into groups of other tumor types. Paired antibodies for each tumor type determined by visual assessment of cluster analysis data and statistical calculations of specificity, sensitivity, and predictive values showed that EMA/CK7 for synovial sarcoma, nestin/S100 for malignant peripheral nerve sheath tumor, and membranous CD99/Fli-1 for Ewing sarcoma yielded high specificity and positive predictive values. Cluster analysis also highlighted aberrant staining reactions and diagnostic pitfalls in these tumors. Hierarchical cluster analysis is an effective method for analyzing high-volume immunohistochemical data.     

Differential diagnosis of gastrointestinal stromal tumor and other spindle cell tumors in the gastrointestinal tract based on immunohistochemical analysis

To confirm the usefulness of an immunohistochemical panel of antibodies for KIT (c-kit/CD117), CD34, desmin, smooth-muscle actin (SMA), h-caldesmon (HCD), S-100 protein, neuron-specific enolase (NSE), and beta-catenin, 297 mesenchymal and peripheral nerve-sheath tumors of the gastrointestinal tract and intra-abdominal locations including 211 gastrointestinal stromal tumors (GISTs), 12 leiomyomas, 18 leiomyosarcomas, 17 solitary fibrous tumors (SFTs), 14 schwannomas, and 25 desmoid-type fibromatoses (DTFs) were analyzed immunohistochemically. Consistent (100%) immunoreactivity for KIT, CD34, desmin and S-100, and nuclear accumulation of beta-catenin were detected in GISTs, SFTs, smooth-muscle tumors, schwannomas, and DTFs, respectively. Immunoreactivity for SMA, HCD, and NSE was observed in a wide range of these tumors. In addition, 418 bone and soft tissue tumors were enrolled in this study for KIT immunostaining. As a result, a limited number of these tumors were KIT positive, including synovial sarcoma that showed morphological similarity to GISTs. These findings suggest that KIT, CD34, desmin, S-100, and beta-catenin are key markers for clinical diagnosis of GISTs and other spindle cell tumors that may involve the gastrointestinal tract, whereas SMA, HCD, and NSE have only limited value.     

NY-ESO-1 expression in synovial sarcoma and other mesenchymal tumors: significance for NY-ESO-1-based targeted therapy and differential diagnosis

A promising targeted therapy against NY-ESO-1 (CTAG 1B) using genetically modified T-cells in synovial sarcomas was recently demonstrated in a clinical trial at the NCI. To investigate the role of NY-ESO-1 immunohistochemistry in patient selection and gain better insight into the incidence of NY-ESO-1 expression in synovial sarcomas and other mesenchymal tumors, we evaluated NY-ESO-1 expression by immunohistochemistry in 417 tumors. This collection of samples included: 50 SS18/SSX1/2 fusion positive synovial sarcomas, 155 gastrointestinal stromal tumors (GIST), 135 other spindle cell sarcomas as well as 77 other sarcomas (chondrosarcoma, osteosarcoma, dedifferentiated liposarcoma, alveolar soft part sarcoma, rhabdomyosarcoma, angiosarcoma, malignant mesothelioma, and Ewing's sarcoma). We report that 76% of synovial sarcomas expressed NY-ESO-1 in a strong and diffuse pattern (2-3+, >50-70% of tumor cells). In contrast, only rare cases of other spindle cell mesenchymal tumor expressed NY-ESO-1 (GIST (2/155), malignant peripheral nerve sheath tumors (1/34), and dermatofibrosarcoma protuberans (2/20)). Individual cases of other sarcomas (angiosarcoma, malignant mesothelioma, chondrosarcoma, osteosarcoma, dedifferentiated liposarcoma, alveolar soft part sarcoma, and Ewing's sarcoma) were positive for NY-ESO-1. However, no positive cases were identified amongst our cohort of leiomyosarcomas (0/24), hemangiopericytoma/solitary fibrous tumors (0/40), and cellular schwannomas (0/17). In summary, we find that NY-ESO-1 is strongly and diffusely expressed in a majority of synovial sarcomas, but only rarely in other mesenchymal lesions. Beyond its role in patient selection for targeted therapy, immunohistochemistry for NY-ESO-1 may be diagnostically useful for the distinction of synovial sarcoma from other spindle cell neoplasms.     

A clinicopathological study on soft tissue tumors of the head and neck.

The present study consists of 651 cases of soft tissue tumors originating in the head and neck area. Among these tumors 628 were benign (96%), while there were only 23 malignant cases (4%). In the benign group hemangiomas showed the highest incidence (47%) followed by tumors of adipose tissue (19%) and those of peripheral nerves (12%). Rare tumors consisted of nodular fascitis, hibernoma, lipoblastomatosis, glomus tumor, granular cell tumor, and chondroma. The majority of cases in the malignant group were either those of muscle origin or blood vessel origin. Excepting for two cases of rhabdomyosarcoma of the embryonal type and two cases of angiosarcoma, all showed recurrence and/or metastasis and terminated in death. Three cases of liposarcoma of either well-differentiated or myxoid type had a good prognosis with all three living for 3 or more years without any recurrence. Other malignant tumors consisted of malignant schwannoma, fibrosarcoma, malignant fibrous histiocytoma, alveolar soft part sarcoma, and chordoma. The age, sex, anatomical location, and differential diagnosis have also been described.     

TEIF蛋白在软组织肉瘤中的表达及意义

目的 观察TEIF蛋白在软组织肉瘤组织中的表达及与类型、分级的关系。方法通过原核表达TEIF蛋白免疫制备多克隆抗体,免疫印迹鉴定。以组织芯片-免疫组织化学（En Vision法）检测166例软组织肉瘤和28例良性肿瘤及瘤样病变标本TEIF蛋白表达。结果制备多克隆抗体经Western印迹鉴定与TEIF具有特异结合性。免疫组织化学显示166例软组织肉瘤中TEIF蛋白阳性97例,阳性率为58％（97／166）,高于良性肿瘤及瘤样病变（11％,3／28）（P＜0．05）。阳性主要分布为：滑膜肉瘤94％（16／17）、原始神经外胚叶瘤（PNET）91％（21／23）,两者高于隆突性皮肤纤维肉瘤43％（6／14）、黏液性纤维肉瘤38％（6／16）、恶性外周神经鞘膜瘤36％（8／22）、脂肪肉瘤32％（6／19）（P＜0．05）,而与恶性纤维组织细胞瘤75％（15／20）、横纹肌肉瘤（7／10）、平滑肌肉瘤64％（9／14）差异无统计学意义（P〉0．05）。同时,TEIF蛋白的弥漫阳性表达（≥2＋）多存在于PNET和滑膜肉瘤,分别为83％（19／23）和76％（13／17）。在法国癌症中心联盟（FNCLCC）分级中,19例Ⅰ级肉瘤中TEIF阳性表达为32％（6／19）,44例Ⅱ级肉瘤阳性率为48％（21／44）,两者中2＋以上阳性分别为11％（2／19）、32％（14／44）,而70例Ⅲ级肉瘤中TEIF阳性表达为84％（59／70）和2＋以上阳性为70％（49／70）。Ⅲ级组的TEIF阳性率（及2＋以上阳性率）显著高于Ⅱ级组和Ⅰ级组（均为P＜0．05）,而后两者间则差异无统计学意义（P＞0．05）。结论 TEIF蛋白表达存在于软组织肉瘤,尤其高表达于PNET、滑膜肉瘤,并与肉瘤的组织学分级有关。     

SYT在诊断单相纤维型滑膜肉瘤中的价值

目的 探讨SYT在单相纤维型滑膜肉瘤(monophasic fibrous synovial sarcoma,MFSS)的诊断及与其它梭形细胞肿瘤鉴别诊断中的作用.方法 收集MFSS 36例、其它梭形细胞肿瘤32例,其中包括恶性外周神经鞘膜瘤7例、纤维肉瘤6例、平滑肌肉瘤4例、恶性纤维组织细胞瘤7例和孤立性纤维性肿瘤8例,检测sYT蛋白在上述病例中的表达.结果 SYT在MFSS中的阳性表达率为91.67%(33/36),其中15例呈弥漫强阳性表达(>80%的瘤细胞核呈强阳性),12例呈不同程度的阳性表达,50%～80%的瘤细胞核呈强阳性表达.SYT在其他梭形细胞间叶肿瘤中的阳性表达率为59.37%(19/32),其中6例呈弥漫强阳性表达(>80%的瘤细胞核呈强阳性),7例呈不同程度的阳性表达,50%～80%的瘤细胞核呈强阳性.结论 SYT蛋白在MFSS和其他梭形细胞肿瘤中均有较强的阳性表达,提示SYT抗体在MFSS与其他梭形细胞肿瘤的鉴别诊断中作用有限.     

Positive immunohistochemical staining of KIT in solid-pseudopapillary neoplasms of the pancreas is not associated with KIT/PDGFRA mutations.

Solid-pseudopapillary neoplasms of the pancreas are uncommon neoplasms of low malignant potential and of uncertain histogenesis. A small percentage of patients develop metastatic disease and some succumb to disease. The management of patients with metastatic disease or unresectable tumor, and patients who are just not good surgical candidates is problematic. Novel therapy targets are needed. Successful treatment of metastatic and unresectable gastrointestinal stromal tumors with KIT kinase inhibitor, imatinib mesylate (Gleevec), makes it intriguing to look at the status of KIT in solid-pseudopapillary neoplasms of the pancreas. In this study, we investigated KIT expression in 50 solid-pseudopapillary neoplasms by immunohistochemical staining. Of the 50 (50%) solid-pseudopapillary neoplasms, 25 showed diffuse expression (in >50% neoplastic cells) of KIT and additional five (10%) cases showed focal staining (in 10-50% neoplastic cells). Expression of KIT was not associated with tumor behavior and prognosis. A subset of 11 cases showing diffuse KIT expression detected by immunohistochemical staining were further evaluated for the presence of activating mutations in KIT exons 9, 11, 13 and 17, and PDGFRA exons 12 and 18 using PCR amplification followed by direct sequencing. However, no KIT or PDGFRA mutations were identified in any of these 11 cases tested, suggesting that the overexpression of KIT is probably not due to activating mutations in KIT or PDGFRA. The exact mechanism of KIT overexpression in solid-pseudopapillary neoplasms remains to be elucidated. One possible mechanism is gene dose effect (increased copies of KIT gene). Experience in gastrointestinal stromal tumors and other tumors have shown that mutation-mediated activation of KIT or PDGFRA is a prerequisite for clinical response with imatinib mesylate. Thus, lack of mutations in KIT or PDGFRA in solid-pseudopapillary neoplasms suggests that imatinib mesylate is less likely to be effective in the treatment for patients with metastatic disease or unresectable tumor, and patients who are just not good surgical candidates.     

Role of electron microscopy in the evaluation of soft tissue neoplasms, with emphasis on spindle cell and pleomorphic tumors

The current significant role of transmission electron microscopy in the evaluation of soft tissue tumors when correlated with conventional histological and immunohistochemical studies is discussed for the following entities: myxofibrosarcoma, storiform-pleomorphic fibrosarcoma (malignant fibrous histiocytoma), and myofibrosarcoma; dermatofibrosarcoma protuberans; hemangiopericytoma; monophasic synovial sarcoma; extrarenal rhabdoid tumor; soft tissue perineurioma; and gastrointestinal stromal tumors, notably the so-called autonomic nerve variant.     

Neuron-specific enolase and Leu-7 immunoreactive small round-cell neoplasm. The relationship to Ewing's sarcoma in bone and soft tissue

The authors present an immunohistochemical analysis of tissue from five cases of morphologically distinctive Ewing's sarcoma in bone and soft tissue. The mean age of the five patients was 16.6 years, with a range of 6-28 years. The tumors existed in chest wall, pelvis, and lower extremities. Two siblings with tumor in bone were clinically diagnosed as having Ewing's sarcoma. All cases had immunoreactivity for neuron-specific enolase (NSE), and four cases revealed positive staining for Leu-7. Neuron-specific enolase is highly specific for neurons and neuroendocrine cells. In addition, immunoreactivity for Leu-7, expressing a natural killer activity, has been demonstrated in peripheral nerve fibers and neuroendocrine cells. The authors suggest that NSE and Leu-7 immunoreactive small round-cell neoplasm is probably a primitive neuroectodermal tumor and should be categorized as Ewing's sarcoma in bone and soft tissue.     

A CLINICOPATHOLOGICAL STUDY ON SOFT TISSUE TUMORS OF THE HEAD AND NECK

The present study consists of 651 cases of soft tissue tumors originating in the head and neck area. Among these tumors 628 were benign (96%), while there were only 23 malignant cases (4%). In the benign group hemangiomas showed the highest incidence (47%) followed by tumors of adipose tissue (19%) and those of peripheral nerves (12%). Rare tumors consisted of nodular fasciitis, hibernoma, lipoblastomatosis, glomus tumor, granular cell tumor, and chondroma. The majority of cases in the malignant group were either those of muscle origin or blood vessel origin. Excepting for two cases of rhabdomyosarcoma of the embryonal type and two cases of angiosarcoma, all showed recurrence andlor metastasis and terminated in death. Three cases of liposarcoma of either well-differentiated or myxoid type had a good prognosis with all three living for 3 or more years without any recurrence. Other malignant tumors consisted of malignant schwannoma, fibrosarcoma, malignant fibrous histiocytoma, alveolar soft part sarcoma, and chordoma. The age, sex, anatomical location, and differential diagnosis have also been described. ACTA PATH. JAP. 29: 389 - 408, 1979.     

Clear cell sarcoma-like tumor with osteoclast-like giant cells in the small bowel: further evidence for a new tumor entity

Most mesenchymal neoplasms of the gastrointestinal tract belong to the category of gastrointestinal stromal tumors (GISTs) and are characterized by the immunohistochemical expression of KIT receptor. In cases without detectable KIT receptor expression several differential diagnoses have to be taken into consideration. Here, we report a case of a 41-year-old man with a tumor of the small bowel composed of large epithelioid tumor cells arranged in solid and alveolar sheets including scattered osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells expressed strongly S-100 protein, vimentin, and to a lesser extent, bcl-2. HMB-45, melan-A, KIT receptor, desmin, smooth-muscle actin, and CD-34 were not detectable. Ki-67 index was 20%. The diagnosis was established by 2 different FISH strategies demostrating the presence of a t(12;22)(q13;q12) translocation, the diagnostic hallmark of clear cell sarcoma of soft parts. Our results provide further evidence for the existence of a new tumor entity designated gastrointestinal clear cell sarcoma with osteoclast-like giant cells. The diagnosis of this entity should be considered in the presence of S-100-positive tumors of the gastrointestinal tract containing multinucleated giant cells and can be established by FISH analysis.     

Immunostaining for SYT protein discriminates synovial sarcoma from other soft tissue tumors: analysis of 146 cases.

Synovial sarcoma in its classic biphasic form can be distinguished readily from other soft tissue lesions; however, monophasic and poorly differentiated forms are diagnostically more problematic. For this reason, we assessed the efficacy of immunostaining for SYT and SSX1 proteins, the gene products resulting from unique synovial sarcoma translocation, to distinguish synovial sarcoma from other soft tissue lesions. A total number of 146 cases were analyzed, including 47 synovial sarcoma cases (all of which were verified by FISH to have t(X; 18) translocation and SYT-SSX fusion gene) and 99 soft tissue tumors of various types. A polyclonal IgG antibody against SYT was used to stain formalin-fixed paraffin embedded tissues. Forty-one out of 47 (87%) synovial sarcoma displayed strong positive nuclear staining (ranging from 80 to 90% of the tumor cells) for SYT antibody. Nineteen of 99 (19%) non-synovial sarcoma cases showed variable nuclear and cytoplasmic staining with SYT, which ranged from 20 to 60% of tumor nuclei, and included malignant peripheral nerve sheath tumor (5/25), solitary fibrous tumor (2/14), Ewing sarcoma (2/6), low grade fibromyxoid tumor (2/4), extraskeletal mesenchymal chondrosarcoma (2/6), gastrointestinal tumor (4/17), epithelioid sarcoma (2/2). The remaining non-synovial sarcomas were negative. This is the first study demonstrating SYT protein expression in tissue sections of synovial sarcoma. This method could provide an easy, rapid and widely applicable means of assisting in the diagnosis of synovial sarcoma, particularly when material and/or resources are unavailable for PCR or FISH-based testing. However, as variable weak staining for SYT may be encountered in a small percentage of non-synovial sarcoma sarcomas, a positive interpretation should be made only when the staining is strong, nuclear and present in the majority of cells.     

L‐type amino acid transporter‐1 and CD98 expression in bone and soft tissue tumors

L‐type amino acid transporter‐1 (LAT1) is expressed in many cancers. We examined LAT1 and CD98 expression immunohistochemically in surgically resected specimens of various bone and soft tissue tumors. Out of 226 cases, 79 (35%) were LAT1⁺ and 95 (42%) were CD98⁺. In bone tumors, LAT1 was highly expressed in osteoblastoma (89%), chondrosarcoma (50%), and osteosarcoma (60%); in soft tissue tumors, LAT1 was highly expressed in rhabdomyosarcoma (80%), synovial sarcoma (63%), Ewing's sarcoma (60%), epithelioid sarcoma (100%) and angiosarcoma (100%). In malignant soft tissue tumors, LAT1 expression was associated with higher histological grade. High CD98 expression was seen in many bone tumors of intermediate and high malignancy. Among soft tissue tumors, CD98 was expressed in tendon sheath giant cell tumor and malignant peripheral nerve sheath tumor (57%), Ewing's sarcoma (50%) and undifferentiated sarcoma (64%). Some of the malignant soft tissue tumors expressed both LAT1 and CD98. This study showed that LAT1 and CD98 was expressed in many malignant and intermediate bone tumors, and some malignant soft tissue tumors.     

The novel marker, DOG1, is expressed ubiquitously in gastrointestinal stromal tumors irrespective of KIT or PDGFRA mutation status

We recently characterized gene expression patterns in gastrointestinal stromal tumors (GISTs) using cDNA microarrays, and found that the gene FLJ10261 (DOG1, discovered on GIST-1), encoding a hypothetical protein, was specifically expressed in GISTs. The immunoreactivity of a rabbit antiserum to synthetic DOG1 peptides was assessed on two soft tissue tumor microarrays. The tissue microarrays included 587 soft tissue tumors, with 149 GISTs, including 127 GIST cases for which the KIT and PDGFRA mutation status was known. Immunoreactivity for DOG1 was found in 136 of 139 (97.8%) of scorable GISTs. All seven GIST cases with a PDGFRA mutation were DOG1-positive, while most of these failed to react for KIT. The immunohistochemical findings were confirmed with in situ hybridization probes for DOG1, KIT, and PDGFRA. Other neoplasms in the differential diagnosis of GIST, including desmoid fibromatosis (0 of 17) and Schwannoma (0 of 3), were immunonegative for DOG1. Only 4 of 438 non-GIST cases were immunoreactive for DOG1. DOG1, a protein of unknown function, is expressed strongly on the cell surface of GISTs and is rarely expressed in other soft tissue tumors. Reactivity for DOG1 may aid in the diagnosis of GISTs, including PDGFRA mutants that fail to express KIT antigen, and lead to appropriate treatment with imatinib mesylate, an inhibitor of the KIT tyrosine kinase.     

低度恶性子宫内膜间质肉瘤临床病理分析

目的 探讨低度恶性子宫内膜问质肉瘤(LESS)的临床病理学特征、诊断和鉴别诊断。方法 分析17例LESS的临床病理特点,通过网织纤维染色、免疫组化染色和电镜观察来研究其病理学特征。结果 LESS临床上主要表现为阴道不规则流血。HE染色见肿瘤组织成巢团样浸润,肿瘤细胞圆形、卵圆形或梭形。肿瘤内有大量的小血管。网织纤维染色见网状纤维丰富,围绕瘤细胞生长。肿瘤细胞14例CD10阳性,12例ER阳性,13例PR阳性,3例actin阳性,C1934、CDll7、Melan—A肿瘤细胞均阴性。电镜观察见肿瘤细胞胞质内的中间丝呈杂乱无序的排列。结论 LESS易误诊,确诊主要依靠组织病理学和免疫组织化学;病理形态上看似良好的低度恶性子宫内膜间质肉瘤,预后不一定好。