胃癌术中腹腔冲洗液CK20mRNA、COX-2 mRNA检测及与腹膜微转移的相关性

目的：运用细胞学及实时荧光定量RT-PCR方法对胃癌术中腹腔冲洗液进行检测,以探讨对预测胃癌腹膜微转移的意义。方法：胃癌50例和胃良性病变10例,收集患者术中腹腔冲洗液,用实时荧光定量RT-PCR方法测定腹腔冲洗液中游离细胞的CK20mRNA、COX-2 mRNA表达,同时作冲洗液细胞学检测（PLC）。结果：50例胃癌患者腹腔冲洗液中CK20mRNA阳性表达为62.0%（31/50）;COX-2 mRNA阳性表达率60.0%（30/50）,CK20mRNA、COX-2 mRNA联合检测阳性率为68.0%（34/50）,皆高于腹腔冲洗液细胞学28.2%（11/50）,CK20mRNA、COX-2 mRNA的阳性率与肿瘤分期、浸润深度、淋巴结转移、浆膜侵犯程度呈正相关。结论：CK20mRNA、COX-2 mRNA实时荧光定量RT-PCR方法检测腹腔微量游离癌细胞较PLC有更高的灵敏度,是一种检测胃癌腹膜微转移的有效方法。     

检测胃癌患者腹腔冲洗液中癌胚抗原mRNA和细胞角蛋白20 mRNA的临床意义

目的探讨采用巢式逆转录聚合酶链反应(RT-PCR)检测胃癌患者腹腔冲洗液中癌胚抗原(CEA)mRNA和细胞角蛋白20(CK-20)mRNA的临床价值。方法收集80例胃癌患者和10例胃良性病变患者的腹腔冲洗液或腹水,常规行HE染色细胞学检查,采用巢式RT-PCR方法检测腹腔冲洗液中CEA mRNA和CK-20 mRNA的表达,并以人胃癌细胞株SGC-7901作为阳性对照。结果80例胃癌患者腹腔冲洗液中CEA mRNA的阳性表达率为52.5%(42/80),CK-20 mRNA的阳性表达率为57.5%(46/80),CEA mRNA和CK-20 mRNA的联合检测阳性率为70.0%(56/80),皆高于腹腔冲洗液细胞学(PLC)检查的27.5%(22/80,P<0.05),且22例PLC检查阳性患者的CEA mRNA和CK-20 mRNA检测结果均为阳性。CEA mRNA和CK-20 mRNA的阳性率与淋巴结转移和TNM分期明显相关(P<0.05)。结论巢式RT-PCR检测胃癌患者腹腔冲洗液中CEA和CK-20基因,可以提高腹腔内游离癌细胞(IFCCs)的检测灵敏度和特异度,对于早期诊断胃癌腹膜微转移有一定的临床价值,可为手术方式选择及术中、术后化疗提供依据。     

实时荧光定量RT-PCR检测胃癌腹腔冲洗液CK20、CEA mRNA

目的研究实时荧光定量RT-PCR方法定量检测胃癌患者腹腔冲洗液中CK20、CEA mRNA的表达,并探讨其临床意义.方法通过实时定量荧光RT-PCR方法,对56例胃癌患者术中腹腔冲洗液中定量检测CK20、CEA mRNA的表达.结果浆膜受侵患者CEA mRNA的表达率61.5%(16/26),明显高于未及浆膜者30.0%(9/30)(P＜0.05).浆膜受侵患者CK20 mRNA的表达率46.2%(12/26)与未及浆膜者56.7%(17/30)(P>0.05)差异无显著性.结论实时定量荧光RT-PCR检测CEA mRNA可作为胃癌腹腔脱落癌细胞的诊断或腹膜转移的预测,指导术中干预治疗.     

流式细胞术在胃癌腹膜转移诊断中的应用价值

目的:探讨检测胃癌腹膜转移诊断的方法.方法:收集50例胃癌患者及10例胃良性病变患者的腹腔冲洗液及临床资料,同时收集胃癌原发灶组织标本做阳性对照.采用流式细胞术检测标本中肿瘤标志物CK19,同时采用HE染色进行腹腔冲洗液细胞学(PLC)检查.结果:胃癌患者腹腔冲洗液中CK19的阳性表达率为62.0%(31例),明显高于PLC检测24.0%(12例)(P＜0.01),且阳性检出率随着肿瘤浸润深度、TNM分期增加而增加.50例胃癌原发灶中CK19的阳性表达率为100%,10例良性病变患者腹腔冲洗液中CK19无阳性表达.结论:流式细胞术可作为预测胃癌腹膜种植转移的手段.其检测CK19可提高腹腔冲洗液中游离癌细胞的检测灵敏度.     

胃癌腹腔冲洗液多巴脱羧酶mRNA的检测

目的：通过检测胃癌腹腔冲洗液中DDCmRNA的表达，探讨多巴胶羟酶（DDC）与胃癌腹膜转移的关系，并为胃癌腹膜转移预测和亚临床转移的筛检提供新的方法．方法：用RNA提取和RT-PCR方法检测92例胃癌腹腔冲洗液中DDCmRNA的表达，同时做腹腔冲洗细胞学（PLC）检查；10例良性疾病的腹腔冲洗液作为阴性对照，结果：92例胃癌腹腔冲洗液中有57例检测到DDCmRNA的表达（62．0％），其表达阳性率与胃癌腹膜转移的PS因素密切相关（P〈0．05）；且胃癌腹腔冲洗液中DDCmRNA的表达水平还与胃癌浸润深度、浆膜类型、PLC检查结果以及是否存在肉眼腹膜转移有关，浸润深度深、浆膜受侵程度重、PLC检查结果阳性及存在肉眼腹膜转移病灶者的DDCmRNA表达相对值明显升高（P〈0．05）；而10例良性疾病腹腔冲洗液均未检测到DDCmRNA的表达．结论：胃癌腹腔液中DDCmRNA的表达与胃癌腹膜转移密切相关，通过RT—PCR来检测DDCmRNA适用于胃癌腹膜转移的预测和亚临床转移的筛检。     

胃癌术中腹腔冲洗液Cox-2 mRNA及CEA mRNA检测临床意义的探讨

目的：探讨腹腔冲洗液Cox-2 mRNA及CEA mRNA检测的可行性和临床意义。方法：前瞻性比较胃癌腹腔冲洗液RT-PCR法与常规细胞学法（PLC）检出脱落癌细胞的阳性率。结果：32例胃癌患者腹腔冲洗液中Cox-2 mRNA及CEA mRNA检出阳性率分别为53．1％（17／32）及56．3％（18／32），明显高于PLC检出癌细胞阳性率（21．9％），Х^2分别为5．497及4．433，P〈0．05。17例RT—PCR法检出阳性病例中，COX-2 mRNA法检出16例（94．1％），CEA mRNA法检出15例（88．2％），两种基因腹腔冲洗液脱落癌细胞检测阳性率大致相同，且检测阳性率与浆膜浸润阳性、浆膜浸润面积大、病理组织学类型、淋巴结转移和TNM病期呈正相关。结论：RT—PCR法检测胃癌腹腔冲洗液Cox-2 mRNA与CEA mRNA表达，可显著提高脱落癌细胞的检测阳性率，具有广泛的临床应用价值和意义。     

腹腔冲洗液L3-PP和整合素α5β1检测对胃癌腹膜种植转移预测价值分析

目的:探讨检测腹腔冲洗液中L3-PP和整合素α5β1对于预测胃癌腹膜种植转移的意义。方法:收集96例胃癌患者腹腔冲洗液,用RT-PCR方法测定冲洗液中游离细胞L3-PP、整合素α5β1及CEA mRNA的表达情况,同时作冲洗液细胞学检查(PLC)。结果:腹腔冲洗液中的L3-PP、α5β1和CEA mRNA的阳性率分别为74.0%(71/96)、65.6%(63/96)和62.5%(60/96),均高于腹腔冲洗液细胞学21.9%(21/96),差异均有统计学意义,χ2值分别为52.174、37.333和32.480,P值均<0.01。L3-PP、α5β1及CEA mRNA的阳性率与肿瘤的浸润深度(χ2=7.898,P=0.046;χ2=10.692,P=0.014;χ2=7.897,P=0.048)、TNM分期(χ2=21.960,P<0.01;χ2=29.266,P<0.01;χ2=22.291,P<0.01)、腹膜转移(χ2=13.919,P<0.01;χ2=16.627,P<0.01;χ2=9.089,P<0.01)等密切相关。对CEA-组和CEA+组的生存分析发现差异均有统计学意义(Log-rank test=8.349,P=0.039;Log-rank test=10.864,P=0.012)。结论:用RT-PCR联合检测腹腔冲洗液中L3-PP和整合素α5β1mRNA可作为预测胃癌腹膜种植转移的方法,为临床医生选择合适的治疗方案提供依据。     

CEA mRNA、CEA蛋白及细胞学检测胃癌腹腔液中游离癌细胞的初步评价

目的　比较腹腔冲洗液中CEAmRNA、CEA蛋白和细胞学检测游离癌细胞及预测腹膜转移的应用价值。方法　术中收集 43例胃癌和 10例胃良性病变的腹水或腹腔冲洗液 ,分别采用RT PCR方法测定腹腔液中游离癌细胞CEAmRNA表达 ,放射免疫检测上清液中CEA蛋白含量 (p CEA) ,同时做腹腔冲洗细胞学 (peritoneallavagecytology ,PLC)检查。结果　CEAmRNA表达阳性率 (5 6 .3% )明显高于p CEA (38.1% )或PLC (33.0 % ,P <0 .0 5～ 0 .0 1)。CEAmRNA表达量随侵袭深度、病期进展而增加 (P <0 .0 5 ) ,因大体类型、浆膜类型不同 ,其阳性表达级别差异有显著性 (P <0 .0 5 )。结论　三种方法均适用于胃癌腹腔脱落癌细胞的诊断或腹膜转移的预测 ,但对微量癌细胞检出的灵敏性 ,以RT PCR方法为优。     

腹腔冲洗液中癌胚抗原、细胞角蛋白20水平预测胃癌患者腹膜微转移和判断预后的临床价值

目的 探讨检测胃癌患者腹腔冲洗液中癌胚抗原（CEA）、细胞角蛋白20（CK-20）水平对胃癌患者预测腹膜微转移和判断预后的价值.方法 收集行D2根治术并达到R0切除的105例胃腺癌患者临床及随访资料.收集患者腹腔冲洗液,常规行HE染色腹腔冲洗细胞学（PLC）检查,采用流式细胞术（FCM）检测患者腹腔冲洗液中CEA和CK-20的表达,以13例需行手术治疗胃良性病变患者作为阴性对照,以人类胃癌细胞株SGC-7901作为阳性对照.结果 105例胃癌患者腹腔冲洗液中CEA的阳性表达率为45.7％（48/105）;CK-20的阳性表达率为63.8％（67/105）;CEA和CK-20的联合检测阳性率为81.0％（85/105）,均高于PLC检查的29.5％（31/105）（P＜0.05）.CEA和CK-20阳性率与肿瘤是否侵犯浆膜、淋巴结转移、pTNM分期有关（P＜0.05）.CEA和CK-20均表达阴性的20例患者中位生存期为52.0个月,长于CEA和CK-20均表达阳性的30例患者（18.0个月）（P＜0.05）.结论 FCM检测,尤其是联合检测胃癌患者腹腔冲洗液中CEA、CK-20的表达可用于预测腹膜微转移,明显优于PLC检测.联合检测胃癌患者腹腔冲洗液CEA、CK-20的表达可有效预测胃癌患者预后.     

胃癌术中腹腔冲洗液CK19检测临床意义的探讨

目的探讨胃癌根治术中腹腔冲洗液CK19的检测与胃腺癌分化程度、TNM分期的关系以及腹腔镜胃癌根治术后对肿瘤细胞腹膜微转移的影响。方法应用流式细胞术法检测50例胃癌患者(分开腹组及腹腔镜组)及同期10例胃良性病变患者腹腔冲洗液的CK19表达,比较腹腔镜辅助下胃癌根治术与传统开腹根治术患者腹腔灌洗液的CK19表达,分析腹腔冲洗液CK19的表达与肿瘤组织分化程度、TNM分期的关系。结果胃良性病变患者腹腔冲洗液CK19阳性表达率为0,低分化腺癌组CK19阳性表达率明显高于高中分化腺癌组(P0.05)。TNM分期Ⅲ期胃癌组腹腔冲洗液CK19阳性表达率显著高于Ⅰ+Ⅱ期患者(P0.05)。腹腔镜辅助下胃癌根治术患者CK19阳性表达率术后较术前检出率虽有所增加但差异无统计学意义,与开腹组相比较差异亦无统计学意义。结论胃癌患者腹腔冲洗液CK19表达水平与肿瘤分化程度、TNM分期有关,腹腔镜辅助下胃癌根治术与传统开腹手术一样,并不增加腹腔冲洗液的CK19阳性表达率和术后肿瘤腹膜微转移的危险性。     

Metabolism of the carcinogen N-hydroxy-N-2-fluorenylacetamide by rat peritoneal neutrophils

The in vitro metabolism of a locally carcinogenic N-hydroxy-N-2-fluorenylacetamide(N-OH-2-FAA) by rat peritoneal polymorphonuclear leukocytes(PMNL), chiefly neutrophils, elicited with intraperitoneal injectionsof proteose peptone, was examined. At 10⁶ PMNL/ml in media containinghalide (X^–), 0.14 M Cl^– ± 0.1 mM Br^–(without Ca⁺⁺ and Mg⁺⁺), addition of 10 nM phorbol myristateacetate (PMA) resulted in generation of superoxide anion andH₂O₂. Subsequent cetyltrimethylammonium Cl^– (Cetac) additionat 0.002% effected myeloperoxidase (MPO) activity release. PMNLtreated with PMA and/or Cetac did not metabolize N-OH-2-FAA(30 µM). However, 1–2 pulses of H₂O₂ (50 µM)after Cetac addition resulted in oxidation of N-OH-2-FAA toN-acetoxy-2-FAA (<0.5 µM) and 2-nitrosofluorene (2-NOF)(1–2 µM). In the presence of Br^– 2-NOF wasincreased (3–5 µM). The results are consistent withoxidation of N-OH-2-FAA by MPO/H₂O₂ and MPO/H₂O₂/X^– viatwo pathways: one electron oxidation leading to N-acetoxy-2-FAAand 2-NOF, and X^–-dependent oxidation to 2-NOF. N-Acetoxy-2-FAA(10 µM) incubated with PMNL under similar conditions wasconverted non-enzymatically to 4-OH-2-FAA (5 µM) and enzymaticallyto N-OH-2-FAA (3 µM). In the presence of H₂O₂, smalleramounts of these products were formed. Formation of N-OH-2-FAAwas prevented by paraoxon (0.1 mM) suggesting O-deacetylaseactivity. However, accountability for N-acetoxy-2-FAA decreasedwith time, presumably because of binding to cellular macromolecules.With H₂O₂ addition, 2-NOF (10 µM) was converted to 0.5or 0.25 µM 2-nitrofluorene by active PMNL or heat-inactivatedcell lysates, respectively. Low recoveries of 2-NOF were alsoattributed to binding. The results suggest that PMNL may beinvolved in activation of the carcinogenic N-arylhydroxamicacids in vivo.     

Ki67-BCL2 index in prognosis of malignant peritoneal mesothelioma

Background: malignant peritoneal mesothelioma (MPM) is a rare peritoneal mesothelial neoplasm. Ki67 and BCL2 are established prognostic markers in several cancers. High Ki67 expression indicates tumour progression, whilst similar expression of BCL2 retards tumour replication. Traditionally, prognosis in MPM is gauged with a single biomarker assessed separately in a dichotomous manner. Here, we examine prognosis with dual biomarkers incorporated in a model to predict survival. Materials and methods: Forty two MPM archival patient tumours were screened for Ki67 and BCL2 by immunohistochemistry and evaluated using standard methods. Ki67 and BCL2 expression was incorporated into a prognostic model to develop Ki67-BCL2 index. Using this index, three hazard groups were identified (high, medium and low risk). Kaplan-Meier survival analysis was performed to assess the significance of these hazard groups in the various clinicopathological categories. Results: In all clinicopathological categories, high risk group showed poor prognosis compared to low risk group (p = < 0.001). Compared to medium risk, high risk group carried poor prognosis in all tumours, females, epitheloid tumours, peritoneal cancer index (PCI) < 20, ≥ 20, age at diagnosis (AAD) < 60, and ≥ 60 years. Independent of the Ki67-BCL2 index, male, sarcomatoid, PCI ≥ 20 and AAD ≥ 60 were poor prognostic factors. High risk group was an independent poor prognostic factor in all tumours, males, females and age < 60 years. The distribution of high risk: low risk group in male and female was 3: 2 and 2: 3, respectively, indicating a gender difference. Comparing hazard ratios generated by Ki67-BCL2 index to that of either Ki67 or BCL2, as a single prognostic biomarker, there was a reduction of HR values. Conclusion: Ki67-BCL2 index seems to suggest a more sensitive method of predicting prognosis. However, the current model needs further evaluation in an independent large cohort sample.     

Intestinal obstruction due to diffuse peritoneal fibrosis at 2 years after the successful treatment of malignant peritoneal mesothelioma with intraperitoneal mitoxantrone

Summary A 44-year-old man who had achieved a complete remission of malignant peritoneal mesothelioma after the intraperitoneal administration of 25 mg/m² mitoxantrone presented with clinical and radiological signs of intestinal obstruction suggestive of recurrent disease at about 2 years following the initial treatment. However, laporotomy revealed extensive adhesive fibrosis but no sign of malignant mesothelioma. The peritoneal complications of intraperitoneal cytostatic treatment are discussed.     

腹膜乳斑与腹腔肿瘤相关性研究进展

腹膜乳斑是腹膜上由免疫细胞围绕血管网组成的特殊免疫结构,属于一种次级淋巴器官,不仅是部分腹腔免疫细胞定居和分化成熟的场所,而且是联系腹腔和外周循环免疫的门户,腹腔和外周血及淋巴器官中淋巴细胞通过腹膜乳斑双向迁移。腹膜及腹腔内针对外来物质的免疫反应,均直接或间接地通过腹膜乳斑来实现。腹腔恶性肿瘤的腹膜转移与腹膜乳斑关系密切,腹膜乳斑不仅是恶性肿瘤腹膜转移的选择性位点,而且是抗肿瘤免疫的发生场所。腹膜乳斑对于恶性肿瘤腹膜转移的临床诊断和防治均具有一定意义。     

腹膜乳斑与腹腔肿瘤相关性研究进展

腹膜乳斑是腹膜上由免疫细胞围绕血管网组成的特殊免疫结构,属于一种次级淋巴器官,不仅是部分腹腔免疫细胞定居和分化成熟的场所,而且是联系腹腔和外周循环免疫的门户,腹腔和外周血及淋巴器官中淋巴细胞通过腹膜乳斑双向迁移.腹膜及腹腔内针对外来物质的免疫反应,均直接或间接地通过腹膜乳斑来实现.腹腔恶性肿瘤的腹膜转移与腹膜乳斑关系密切,腹膜乳斑不仅是恶性肿瘤腹膜转移的选择性位点,而且是抗肿瘤免疫的发生场所.腹膜乳斑对于恶性肿瘤腹膜转移的临床诊断和防治均具有一定意义.     

PLOD2 as a potential regulator of peritoneal dissemination in gastric cancer

Peritoneal dissemination is the most common metastatic pattern in advanced gastric cancer (GC) and has a very poor prognosis. However, its molecular mechanism has not been elucidated. Our study investigated genes associated with peritoneal dissemination of GC. We performed combined expression analysis of metastatic GC cell lines and identified Procollagen‐lysine, 2‐oxoglutarate 5‐dioxygenase2 (PLOD2) as a potential regulator of peritoneal dissemination. PLOD2 is regulated by hypoxia‐inducible factor‐1 (HIF‐1) and mediates extracellular matrix remodeling, alignment, and mechanical properties. We analyzed PLOD2 expression immunohistochemically in 179 clinical samples, and found high PLOD2 expression to be significantly associated with peritoneal dissemination, leading to poor prognosis. In an in vivo‐collected metastatic cell line, downregulation of PLOD2 by siRNA reduced invasiveness and migration. Hypoxia upregulated PLOD2 mediated by HIF‐1, and promoted invasiveness and migration. After exposure to hypoxia, a cell line transfected with siPLOD2 exhibited significantly suppressed invasiveness and migration, despite high HIF‐1 expression. These findings indicate that PLOD2 is a regulator of, and candidate therapeutic target for peritoneal dissemination of GC. Although peritoneal dissemination of GC has a very poor prognosis, its molecular mechanism has not been elucidated. We identified PLOD2 regulated by HIF‐1 as a potential regulator of peritoneal dissemination of GC. Finally, we showed that PLOD2 promotes cell invasiveness and migration in GC under hypoxia and lead to peritoneal dissemination of GC.     

ICAM-2 gene therapy for peritoneal dissemination of scirrhous gastric carcinoma.

PURPOSE: Human scirrhous gastric carcinoma develops peritoneal dissemination with high frequency, and the prognosis of patients with peritoneal metastasis is poor. There have been few reports of an immunogene therapy for peritoneal dissemination. Intercellular adhesion molecule (ICAM)-2 is a second ligand of leukocyte function-associated antigen-1, which functions as a costimulatory molecule for effector cells. In the present study, we examined whether ICAM-2 transfection using adenovirus vector is effective gene therapy for peritoneal metastasis of gastric cancer. EXPERIMENTAL DESIGN: We constructed an adenovirus vector, AdICAM-2, that encodes the full-length human ICAM-2 gene under control of the cytomegalovirus promoter. This vector expresses high levels of ICAM-2 on the human gastric cancer cell line OCUM-2MD3, which has high peritoneal metastatic ability in nude mice. We investigated the antitumor effects of gene transfer of ICAM-2 using the adenovirus vector AdICAM-2 in vitro and in vivo. RESULTS: ICAM-2 expressed on OCUM-2MD3 cells by AdICAM-2 demonstrated significantly high adhesiveness to and cytotoxicity against peripheral blood mononuclear cells in vitro compared with the control adenovirus vector AdlacZ. Intratumoral injection of AdICAM-2 significantly inhibited the growth of s.c. tumor. Mice with peritoneal metastasis survived for a significantly longer time after AdICAM-2 injection, compared with injection of AdlacZ. Histopathological findings revealed that many natural killer cells infiltrated the peritoneal metastatic lesions after AdICAM-2 injection. CONCLUSIONS: These findings suggest that transduction of ICAM-2 into cancer cells enhances the adhesion and activation of natural killer cells, resulting in a reduction of peritoneal metastasis. ICAM-2 transfection using adenovirus vector might be an effective form of gene therapy for peritoneal metastasis of gastric cancer.     

Malignant peritoneal mesothelioma

BACKGROUND AND OBJECTIVES: The incidence of malignant peritoneal mesothelioma (MPM) is rising. Our aim was to present our experience with this entity in order to increase the awareness about this disease to avoid misdiagnosis. METHODS: Records of seven patients with histologically confirmed MPM were retrospectively reviewed. Demographic and clinicopathological findings were studied in detail. RESULTS: There were two females and 5 males; mean age was 50.3 years (range 16-73). Asbestos exposure was recorded in two patients, familial Mediterranean fever in one and previous radiation in one. Main presentations were abdominal pain and distension. None of the patients was diagnosed preoperatively. The average delay in diagnosis was 10 months. Calretinin expression was identified in all tumors. Three patients were treated with cytoreductive surgery combined with systemic chemotherapy. Two patients who remain alive were young female patients who were diagnosed by laparoscopic incidental findings and were treated with cytoreductive surgery combined with hyperthermic intraoperative intraperitoneal chemotherapy (HIIC). Median survival was 19.7 months. The average survival time of the five patients who died of their diseases was 10.2 months. CONCLUSIONS: An awareness of MPM is important to prevent misdiagnosis. Immunohistochemistry has an important role in confirming the diagnosis. MPM remains a difficult therapeutic challenge. Thorough cytoreductive surgery is the cornerstone of current treatment while HIIC is a promising strategy in suitable patients.     

Malignant peritoneal mesothelioma

BACKGROUND: The clinical characteristics of malignant peritoneal mesothelioma are not fully known, and it appears as a variable entity with different types of clinical presentation and with a difficult diagnosis. PATIENTS: Fifteen patients with malignant peritoneal mesothelioma were analyzed for asbestos exposure, clinical presentation, thrombocytosis, X-rays and echotomographic findings, peritoneal fluid cytology, surgical investigations, diagnosis in vita, therapy, cause of death, diagnosis time, and survival time. RESULTS: Asbestos exposure was present in 12 men. Abdominal pain, ascites, abdominal mass, weight loss and fever were the most common presentation symptoms. In 5 patients, the disease presented as a surgical emergency. Assembling the presenting symptoms, malignant peritoneal mesothelioma was subdivided in 3 types: classical (6 cases), surgical (5 cases) and medical (4 cases). Thrombocytosis was present in 11 cases. Peritoneal fluid cytology was positive for neoplastic mesothelial cells in 8 of 10 cases. Laparotomy (5 patients) and laparoscopy (7 cases) were diagnostic in all cases. Diagnosis in vita was malignant peritoneal mesothelioma for 13 patients, peritoneal carcinomatosis for 1, with only 1 autopsy diagnosis. Seven patients were treated with chemotherapy, showing a progression of the disease. Mean symptoms-to-diagnosis time was 122 days (4-410), and mean symptoms-to-survival time was 345 days (45-1510). CONCLUSIONS: Malignant peritoneal mesothelioma is a very unusual disease characterized by a difficult diagnosis, a rapid evolution, a poor response to therapy, and a very high prevalence of thrombocytosis. A new clinical classification into three types (classical, surgical and medical) may be useful for a correct diagnosis. The early diagnosis of malignant peritoneal mesothelioma remains an important open question.