CD163在皮肤梭形细胞肿瘤中的诊断价值

皮肤恶性梭形细胞肿瘤种类较多,如非典型纤维黄色瘤(AFX)、梭形细胞鳞状细胞癌(SCC)、梭形细胞/促纤维增生性恶性黑色素瘤、皮肤隆突性纤维肉瘤(DFSP)和平滑肌肉瘤等,这些恶性梭形细胞肿瘤的形态学诊断有时比较困难.一般来说,AFX是一个排除性诊断,是根据免疫标记CK和S-100蛋白表达阴性,而组织细胞标记物CD68表达阳性而做出的诊断.     

隆突性皮肤纤维肉瘤72例临床病理学观察

目的 观察隆突性皮肤纤维肉瘤(DFSP)的临床病理特点，探讨诊断、鉴别诊断及其组织起源。方法 对72例DFSP病例进行临床表现、组织形态学、免疫组化研究，16例真皮纤维瘤(DF)、19例神经纤维瘤(NF)、17例纤维肉瘤(FS)分别作为对照。结果 72例DFSP好发中青年男性，肿瘤为单发或多发性结节，位于真皮，可浸润皮下脂肪及横纹肌。组织形态除经典的车辐状或席纹状结构外，还存在一些变异如黏液变性、伴FS区域、Bednar瘤等。DFSP组87％CD34阳性，NF组42％CD34阳性。结论 掌握DFSP的临床病理特点，避免与其它皮肤梭形细胞肿瘤尤其是DF、NF及黏液性肿瘤混淆。CD34阳性提示DFSP可能与神经鞘膜有关。     

隆突性皮肤纤维肉瘤远处转移4例临床病理分析

目的 探讨隆突性皮肤纤维肉瘤(dermatofibrosarcoma protuberans, DFSP)远处转移的临床病理学特征和转移的高危因素。方法 收集4例转移性DFSP的临床资料，行免疫组化和FISH检测，并复习相关文献。结果 4例转移性DFSP,原发灶1例为经典型DFSP,1例为经典型DFSP伴20%黏液样变，2例为纤维肉瘤型隆突性皮肤纤维肉瘤(fibrosarcomatous dermatofibrosarcoma protuberans, FS-DFSP);4例转移灶为FS-DFSP,均发生肺转移，1例合并头部顶叶转移。经典型DFSP组织学表现为梭形肿瘤细胞呈席纹或漩涡状排列，FS-DFSP除有经典型DFSP区域外，还可见纤维肉瘤样区域。原发灶弥漫表达CD34,1例转移灶CD34表达缺失，1例p53表达增加，FS-DFSP核分裂象与Ki-67增殖指数均高于经典型DFSP。结论 FS-DFSP与经典DFSP相比，侵袭性更强，转移风险更大。肿物局部切除是经典型DFSP进展为FS-DFSP的高危因素，建议尽早扩大切除，减少肿瘤进展风险。     

肌样型隆突性皮肤纤维肉瘤中肌样区域的组织发生和性质

目的探讨肌样型隆突性皮肤纤维肉瘤(DFSP)中肌样区域的组织发生和性质。方法对95例DFSP中筛选出的15例肌样型DFSP进行光镜和免疫组织化学研究。结果临床资料显示女性比男性稍多见(1．5：1)。18～40岁为发病高峰年龄段(73％)。肿瘤部位常见于躯干和肢体(11／15)。镜检：在15例肌样型DFSP中(9例为纤维肉瘤型，最为常见；4例为经典型；2例为色素型，后者伴有肌样区域未见文献报道)均观察到散在分布的肌样结节和肌样束，即肌样区域，且与瘤内血管壁平滑肌细胞增生有密切的关系，并发现血管壁改变具有不同程期的特点。早期：瘤内小血管和少许较大血管壁平滑肌细胞显著增生，细胞无异型性，可见核分裂象；中期：增生的平滑肌细胞形成特征性的嗜伊红性肌样结节和肌样束，可伴轻度玻璃样变，在大多数肌样结节和肌样束中常可见偏位、不规则、变小变窄的血管腔；后期：肌样结节和肌样束可相互融合，血管腔萎陷或消失，伴有广泛玻璃样变甚至钙化。免疫表型：肌样结节和肌样束呈SMA、MSA、Vim弥漫强阳性，但对Des、smooth muscle myosin、caldesmon和CD34均呈阴性。需特别指出的是肌样结节和肌样束中偏位的血管腔衬覆的内皮细胞呈CD34阳性，证实了肌样区域与血管壁的密切关系。结论肌样型DFSP是DFSP的一种少见的组织学亚型。组织发生是来源于瘤内血管壁增生的平滑肌细胞，性质属非肿瘤性成分，而不是来源于瘤内肿瘤细胞向肌纤维母细胞分化或反应性肌纤维母细胞增生，但在特殊的条件下血管壁增生的平滑肌细胞可以转化为肌纤维母细胞。     

乳腺上皮样型管周间质肉瘤病理特征及与叶状肿瘤比较观察

目的 探讨乳腺上皮样型管周间质肉瘤的临床病理特点及与叶状肿瘤的关系。方法 采用HE、特殊染色、免疫组化染色(CK，EMA，S-100蛋白，SMA，Vim，Des，MG，CD34，CD99，CD117，PR，HMB45)对1例乳腺上皮样型管周间质肉瘤与5例叶状肿瘤(良性、交界性各1例，恶性3例)做比较性观察。结果 乳腺管周间质肉瘤(上皮样型)有独特的镜下图像：①显著的多角形(上皮样)细胞绕导管或小管的上皮肌上皮层呈间质性增生，无叶状结构；②组织学模式有袖套状、花冠状、菊形团状、结节状、融合结节状和片状浸润；③瘤细胞形态有：多角形(大、小)、柱状和梭形。多角形细胞呈上皮样形态，异型明显，核分裂象多见(10～30个／10HPF，个别区域达6个／1HPF)，病理性核分裂象易见，在浸润灶内见肿瘤性坏死；④瘤细胞Vim弥漫阳性、EMA灶性阳性、CD99和CD117灶性弱阳性、CD34少数阳性，CK、SMA、S-100蛋白、Des、MG、PR、HMB45均阴性。5例叶状肿瘤均具备叶状结构、间质过度增生、细胞密集(异质性分布)、核分裂象2～10个／10HPF等诊断要素。在3例恶性叶状肿瘤中，2例有极少的上皮样袖套状病灶，2例有梭形细胞袖套状病灶。结论 乳腺上皮样型管周间质肉瘤是一种极罕见的恶性纤维上皮肿瘤亚型，它可能是恶性叶状肿瘤的最早期病变，也可能是一种独特的类型。     

阴茎假血管肉瘤样鳞状细胞癌1例及文献复习

目的探讨阴茎假血管肉瘤样鳞状细胞癌(SCC)的诊断、组织学和免疫组化特征以及鉴别诊断。方法通过HE、免疫组化及特殊染色观察1例阴茎原发假血管肉瘤样鳞状细胞癌，并复习文献。结果镜下可见显著的棘细胞松解，肿瘤由排列呈腔隙状、网状结构的长梭形细胞组成，细胞异型性明显，核分裂象易见，胞质大多红染，局部区域弥漫出血坏死。免疫表型：CK、Vim阳性，CD34、CD31、SMA、FⅧRAg阴性。网状纤维染色不显示血管外形。结论假血管肉瘤样SCC是一种罕见的易与敌国管肉瘤混淆的特殊形态的SCC．需与血管肉瘤、癌肉瘤等鉴别。     

黏液纤维肉瘤7例临床病理分析

目的 探讨黏液纤维肉瘤临床病理特点。方法收集7例黏液纤维肉瘤患者的临床及病理资料，并对手术切除的标本进行多种抗体免疫组织化学染色，抗体包括CD117、CD34、CD99、actin、S-100蛋白、vimentin等。结果黏液纤维肉瘤多见于男性，年龄37～72岁，中位年龄52岁，主要以不完全纤维性间隔的多结节行为为特征性表现，黏液区与细胞密集区交错排列，细胞密集区可见特征性曲线型血管，肿瘤细胞围绕在其周围排列。免疫表型：vimentin、CD99阳性，其他抗体多呈阴性。结论黏液纤维肉瘤为一侵袭性较强的软组织肉瘤，与多种黏液性肿瘤需要鉴别，易局部复发，宜采取以手术切除为主的综合性治疗。     

子宫Müllerian腺肉瘤伴间质横纹肌样瘤分化1例并文献复习

目的探讨子宫Muellerian腺肉瘤伴间质横纹肌样瘤分化的临床病理特征。方法用光镜、组织化学及免疫组化方法观察其病理组织学表现。结果肿瘤由良性上皮成分和肉瘤性间质成分组成，肉瘤成分过度生长。肿瘤细胞弥漫浸润性分布，细胞大，胞质丰富嗜酸性并可见嗜伊红包涵体。免疫表型：vimentin、CK、NF、CD57、CD99、CgA、Syn阳性，SMA散在阳性，而desmin、EMA、CD10、GFAP、MyoD1、Inhibin—α、HMB45和S-100蛋白阴性。组织化学染色PAS阴性，网状纤维染色显示网状纤维包绕单个或小巢肉瘤性间质细胞。结论子宫腺肉瘤伴间质横纹肌样瘤分化是一种罕见的混合性Muellerian肿瘤，应与子宫内膜间质肉瘤、子宫横纹肌肉瘤和低分化癌等鉴别。     

乳腺隆突性皮肤纤维肉瘤2例并文献复习

目的探讨乳腺隆突性皮肤纤维肉瘤(dermato fibrosarcoma protuberans, DFSP)的临床病理特征。方法收集昆明医科大学第一附属医院病理科诊治的2例乳腺DFSP,分析其临床病理特征,并复习相关文献。结果 2例患者均为37岁女性,有乳腺肿块切除史。镜下见梭形肿瘤细胞呈编织、席纹状密集排列,深部呈蜂窝状浸润脂肪组织。免疫组化标记CD34均弥漫阳性,广谱CK、FⅧ-RAg、desmin、S-100均阴性。例1行荧光原位杂交示COL1A1-PDGFB基因融合。术后分别随访12、90个月,患者均无复发转移。结论 DFSP是一种比较少见的软组织肿瘤,发生于乳腺的DFSP更为罕见。粗针穿刺活检标本诊断,需与乳腺原发的梭形细胞肿瘤鉴别,结合肿瘤具体部位、影像学检查及免疫组化综合诊断,必要时辅以分子病理学检测。     

滤泡性树突状细胞肉瘤临床病理观察

目的探讨滤泡性树突状细胞肉瘤的临床病理特点及免疫表型,提高对该肿瘤的认识和诊断水平。方法通过光镜、电镜和免疫组织化学染色[EnVision法,所选用抗体为：CK（AE1／AE3）、S-100蛋白、CD1a、CD21、CD23、CD35、CD34、CD68、波形蛋白、结蛋白、HMB45、p53]观察并结合临床资料对5例滤泡性树突状细胞肉瘤进行临床病理分析。5例均获随访。结果5例患者中男3例,女2例,平均年龄37岁。肿瘤均位于头颈部淋巴结。镜下观察：肿瘤组织呈片巢状、束状或旋涡状排列,瘤细胞卵圆形或梭形,胞质丰富淡嗜酸性;核卵圆形或胖梭形,趋向不规则成簇分布,散见多核巨细胞;核染色质稀疏,核仁小而清楚;核分裂象数目不等,有时显示明显的核异型。瘤细胞CD21、CD23、CD35阳性,少数瘤细胞CD68、S-100蛋白阳性,CD1a、CD34、HMB45、CK均阴性。电镜下瘤细胞有长而明显的绒毛状胞质突起及特征性的桥粒样连接,未见Birbeek颗粒。随访5～52个月（平均26个月）,无复发或再复发及转移。结论滤泡性树突状细胞肉瘤是一种少见的恶性肿瘤,预后不确定。正确诊断需要病理组织形态、电镜及免疫组织化学相结合,并应与朗格汉斯细胞肉瘤、指突状树突状细胞肉瘤、恶性纤维组织细胞瘤、黑色素瘤、梭形细胞癌等相鉴别。     

伴有肌样/肌纤维母细胞性分化的隆突性皮纤维肉瘤的临床病理分析

目的 探讨隆突性皮纤维肉瘤（ＤＦＳＰ）中肌样／肌纤维母细胞性分化的本质及其临床病理学意义。方法 采用常规ＨＥ切片对１２４例ＤＦＳＰ进行筛选,对6例伴有肌样／肌纤维母细胞性分化的ＤＦＳＰ病例进行免疫组织化学标记,其中２例加做电镜检测。结果 肌样／肌纤维母细胞性分化多出现在纤维肉瘤型ＤＦＳＰ（ＦＳ－ＤＦＳＰ）中,表现为肿瘤周边部或肿瘤内散在性分布的深嗜伊红色小结节或短要束,由梭形细胞组成,细胞多无异型性,核分裂象也罕见,形态上似平滑肌细胞或肌纤维母细胞。免疫组织化学标记显示肌样区域细胞表达α－平滑肌肌动蛋白和肌物质特异性肌动抗原,不表达ＣＤ３４;电镜观察证实细胞含有质膜下微丝束、局灶性致密体及微胸饮囊泡样结构,与肌纤维母细胞相一致,结论 ＤＦＳＰ中的肌样／肌纤维母细胞性分化可能是间质中肌纤维母细胞增生的结果,并非代表了瘤细胞的真性肌纤维母细胞性分化。     

Immunohistochemical characterization of atypical fibroxanthoma and dermatofibrosarcoma protuberans.

Atypical fibroxanthoma (AFX) and dermatofibrosarcoma protuberans (DFSP) have generated undue interest regarding their histogenesis, biological behavior, and differentiation from other forms of spindle cell tumors of the skin, including spindle cell squamous carcinomas and desmoplastic melanomas. To identify characteristic immunophenotypes, 12 AFXs and 15 DFSPs were examined with a panel of antibodies against cytokeratin; vimentin; desmin; proteolytic enzymes (alpha-1-antitrypsin and alpha-1-antichymotrypsin); melanoma-associated antigens defined by HMB-45, HMB-50, and NKI/C3; muscle-specific actin (HHF-35); and S-100 protein. The staining patterns of these two tumors were nearly identical. All cases tested negative for cytokeratin, desmin, and S-100 protein and strongly positive for vimentin. Six (50%) AFXs and 12 (80%) DFSPs tested focally positive for muscle-specific actin. None of the cases were reactive with melanoma antibodies HMB-45 and HMB-50; NKI/C3 strongly stained 26 of 27 tumors. Compared to HMB-45 and HMB-50, NKI/C3 cross-reacted with nonmelanocytic neoplasms. Two AFXs stained for alpha-1-antitrypsin and alpha-1-antichymotrypsin. This study confirms (1) the immunophenotypic similarity of AFX and DFSP, (2) the presence of myofibroblastic differentiation in both tumors, as reflected by HHF-35 staining, and (3) that AFX and DFSP are easily distinguished from spindle cell squamous carcinoma and desmoplastic melanoma by the absence of cytokeratin, HMB-45, and HMB-50 staining.     

Chordomas with malignant spindle cell components. A DNA flow cytometric and immunohistochemical study with histogenetic implications.

The authors studied four chordomas with malignant spindle cell components (SCs) and 12 conventional chordomas (CCs) by DNA flow cytometry using paraffin-embedded tissue. In addition, immunohistochemical stains for a variety of epithelial and mesenchymal markers were performed. The four SCs contained areas histologically identical to conventional chordomas, as well as a high-grade malignant spindle cell component. All four (100%) SCs had an aneuploid-multiploid DNA content. Of interest, the conventional chordoma areas in these tumors had DNA contents different from those containing the high-grade malignant spindle cells. In contrast, only three (27%) of the 11 conventional chordomas with analyzable histograms had an aneuploid-multiploid DNA content. Immunohistochemical studies performed on the four SCs showed the high-grade malignant spindle cells to stain strongly for vimentin and weakly for cytokeratin, S-100 protein, and epithelial membrane antigen (EMA), whereas the areas of conventional chordoma in these same neoplasms stained moderately for vimentin and S-100 protein, and strongly for cytokeratin and EMA. In two cases, the staining for EMA and cytokeratin highlighted a gradual transition between the areas of conventional chordoma and the spindle cell areas. The immunohistochemical staining pattern of the 12 conventional chordomas was similar to that seen in the conventional chordoma components of the four chordomas with malignant spindle cell components. These results suggest that: 1) aneuploidy is more common in SCs than in CCs, and 2) some SCs are multipotential neoplasms in which the neoplastic cells are capable of differentiation along both epithelial and mesenchymal pathways.     

隆突性皮肤纤维肉瘤的形态转化及其恶性潜能

目的：探讨隆突性皮肤纤维肉瘤的形态转化及其恶性潜能。方法：采用ＨＥ和组织化学染色,对４８例隆突性皮肤纤维肉瘤作临床病理分析。结果：４８例肿瘤被分为普通型、粘液型和纤维肉瘤变３个亚型。结论：普通型隆突性皮肤纤维肉瘤是一种低度恶性肿瘤,纤维肉瘤变型的恶性度更高,粘液型的恶性度与其它两型的差异尚待观察。     

Dermatofibrosarcoma protuberans: An analysis of proliferative activity, DNA flow cytometry and p53 overexpression with emphasis on its progression

The aim of this study is to evaluate the degree and spectrum of malignancy of dermatofibrosarcoma protuberans (DFSP) in the aspect of proliferative activity, flow cytometric DNA analysis, and p53 immunoreactivity. Twenty-three tumors from 19 cases of DFSP including three cases of DFSP with fibrosarcomatous areas (DFSP-FS) were studied in comparison with its allied fibrohistiocytic tumors; that is, dermatofibroma (DF; 46 cases), fibrosarcoma (FS; four cases), and malignant fibrous histiocytoma (MFH; 11 cases). MIB-1 labeling index (LI) of DFSP was significantly higher than that of DF and was lower than those of FS and of MFH. In ordinary DFSP, the recurrent tumors exhibited significantly higher MIB-1 LI than that of the primary tumors, whereas the primary tumors showed almost the same proliferative activity of DF. DFSP-FS tended to have a higher proliferative activity than DFSP without FS-area (ordinary DFSP). In five of 19 cases of DFSP, aneuploidy (near-diploidy) was found in four recurrent and one primary tumors. Immunohistochemical p53 overexpression was found in three of 19 cases of DFSP which also showed higher proliferative activity and aneuploidy. All cases of DF were immunohistochemically negative for p53, but most of the cases of FS and MFH were positive. Although DFSP has been classified in a category of fibrohistiocytic tumor of intermediate malignancy, the recurrent DFSP, DFSP-FS, and DFSP with aneuploidy and/or p53 overexpression could be a subgroup of DFSP with more aggressive clinical behavior than ordinary primary ones.     

Origin of the desmoplasia in desmoplastic malignant melanoma

Four cases of desmoplastic malignant melanoma were examined light microscopically and immunohistochemically. Electron microscopy was performed in three cases. Light microscopy showed that all tumors were composed of neoplastic spindle cells that infiltrated between mature collagen bundles in the reticular dermis. Some of the spindle cells had bizarre nuclei, whereas other spindle cells resembled normal fibroblasts. Melanin could not be demonstrated in any of the tumors by histochemical techniques. Electron microscopic examination of the spindle cells showed prominence of rough endoplasmic reticulum, which was dilated and filled with flocculent material and occasional collagen fibrils. The same cells contained aggregates of non-membrane-bound melanin granules and pre-melanosomes. Some cells also showed features of myofibroblasts. Immunoperoxidase staining with anti-S100 protein antibody demonstrated positivity of the spindle cells as well as of melanocytes in the basal layer of the epidermis. Scar tissue and fibroblasts did not stain. These findings show that the desmoplastic component of these malignant melanomas derives from melanocytes that have undergone adaptive fibroplasia. Therefore, in assessing depth of invasion in a malignant melanoma, measurements should include the desmoplastic areas.     

乳腺肉瘤样癌

观察乳腺肉瘤样癌的病理形态学特点,分型,并分析其与某些肿瘤的鉴别诊断。方法１５３８例乳腺恶性肿瘤中１５例（０．９８％）诊断为乳腺肉瘤样癌,行ＡＥ１／ＡＥ３、上皮膜抗原（ＥＭＡ）、波形蛋白、Ｓ－１００蛋白、肌动蛋白、雌激素受体（ＥＲ）和孕激素受体（ＰＲ）ＳＰ法免疫组织化学染色。另有６例是外院会诊病例,共２１例。结果按其肉瘤样成分的特点分为４个形态学类型：（１）多形肉瘤型：肉瘤样成分为多形肉瘤样。（２     

肾脏黏液性管状和梭形细胞癌的临床及病理学特点

目的 探讨肾脏黏液性管状和梭形细胞癌的临床病理学特点.方法 分析7例肾脏黏液性管状和梭形细胞癌的临床特点、组织形态及免疫表型特点[CD10、CK7、CK18、CK19、Villin、上皮细胞膜抗原(EMA)、P504S和波形蛋白],并复习相关文献.结果 7例黏液性管状和梭形细胞癌中,男性3例,女性4例,平均年龄48.2岁(39～61岁).均为体检时发现肿瘤,肿瘤最大径平均5.5 cm(4.0～9.0 cm),术后随访18～51个月,得到随访资料的5例均无复发及转移.肿瘤大体切面均为实性、灰白色,无包膜,但与周围肾组织分界清晰.镜下观察肿瘤细胞主要由两种形态构成:均一的由立方细胞构成的紧密排列的小管状结构和梭形细胞成分.两种成分比例或多或少,交错分布,其中5例伴有黏液样基质,3例见到明显的透明细胞区域,1例可见灶状肉瘤样区域,1例见乳头状结构及泡沫细胞.免疫组织化学染色显示,7例肿瘤CK7均呈阳性表达,EMA、CK18和P504S在染色的5例中全部呈阳性表达,CK19在染色的5例中有4例表达,而CD10、Villin和波形蛋白表达差异较大.结论 肾脏黏液性管状和梭形细胞癌是一种低度恶性的多形性肿瘤,组织形态学谱系较宽,不典型的病例可以主要由两种成分之一构成,并缺少黏液,有些病例可见到透明细胞、乳头状结构,少数可见肉瘤样形态及坏死.免疫表型上对于从近曲小管到集合管的标志物均有表达.

Abstract：

Objective To investigate the clinical and pathological features of the mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney. Methods Seven cases of MTSCC were analyzed by gross examination and light microscopy. Immunostaining was performed to detect the expression of CD10, CK7, CK18, CK19, Villin, EMA, P504S and vimentin. The literature on this tumor was reviewed to discuss the histological features of MTSCC and its clinical behavior. Results Three of 7 cases were male and the other 4 were female. The mean age of the patients was 48.2 years old, with a range from 39 to 61 years. All the patients presented no symptom and their tumors were found by health examination. Tumors averaged 5.5 cm in greatest dimension (range from 4.0 cm to 9.0 cm). The tumors were well-circumscribed without capsules, and the cut surfaces were solid and soft with white-tan color. By light microscopy, tumors were composed of tightly packed, small, elongated tubules with transitions to spindle cell components. Five cases had mucinous stroma. Clear cell clusters, focal sarcomatoid differentiation, papillations and foamy macrophages were seen in several cases. Immunohistochemically, all 7 cases showed positive for CK7, five of 5 cases positive for EMA, CK18 and P504S, four of 5 cases positive for CK19, but heterogeneous for CD10, villin and vimentin expression. No evidence of local recurrence or distant metastases was identified in the 5 patients with follow-up information. Conclusions The mucinous tubular and spindle cell carcinoma is a low-grade and polymorphic neoplasm. The morphology of these tumors may not be uniform with a wide histological spectrum. The tumors can be tubular predominant or spindle cells predominant with scant to abundant mucinous stroma, which coupled with the presence of other unusual features such as clear cells, papillations, foamy macrophages, necrosis and sarcomatoid differentiation. Immunohistochemically, MTSCC can express the markers from the proximal convoluted tubules to collecting tubules.     

Nodular erythema elevatum diutinum mimicking cutaneous neoplasms

Aims : We describe the cutaneous pseudoneoplastic lesions in two patients with nodular erythema elevatum diutinum, a rare chronic disorder in which polymorph nuclear fragmentation (leukocytoclasis) is present within dermal nodules showing spindle cells and fibrosis. In both cases diagnostic difficulty was encountered clinically and pathologically and various benign and malignant neoplasms were considered in the differential diagnosis. Methods and results : Immunohistochemically the spindle cells were negative for CAM5.2, AE1/3, S100 protein and desmin (D33). They were positive for vimentin and focally positive for CD34 and α-smooth muscle actin. Some of the spindle cells were positive for Mac 387 and KP1(CD68). By electron microscopy, the lesions were shown to consist of fibroblasts/myofibroblasts and fusiform macrophages. Conclusions : Increased awareness of the features described will help to avoid misdiagnosis as a neoplastic process.     

Mixed mesodermal tumor of the ovary: Immunohistochemical study with histogenetic consideration

The clinical, histological and immunohistochemical features of three cases of ovarian mixed mesodermal tumor (MMT) were examined. The epithelial component was serous papillary cystadenocarclnoma in case 1 and 3, and endometrioid adenocarcinoma in case 2. In case 1, undifferentiated adenocarcinoma was also seen. The mesenchymal component was fibrosarcomatous and chondrosarcomatous in case 1 and 2. In case 3, only fibrosarcomatous area was seen. No endometriosis was observed. Immunohistochemically, the epithelial component showed positivity for epithelial membrane antigen in all three cases. S-100 protein was positive in two cases with chondrosarcomatous differentiation. The fibrosarcomatous area showed positivity for vimentin in all three cases. However desmin, myosin and myoglobin were negative. The antibodies thought to be epithelial or mesenchymal markers unexpectedly reacted positively in some cells; for example, EMA was positive in fibrosarcomatous and chondrosarcomatous cells. Therefore, it was speculated that because the undifferentiated tumor cells had a biphasic character, MMT might originate from immature multipotential cells of surface epithelium and subcapsular connective tissue of the ovary.