CT影像组学联合CT特征预测肺亚实性结节侵袭性

目的 观察CT影像组学联合CT特征预测肺亚实性结节侵袭性的价值。方法 回顾性分析170例肺亚实性结节患者资料,包括6例非典型腺瘤样增生(AAH)、12例原位腺癌(AIS)、58例微浸润性腺癌(MIA)及94例浸润性腺癌(IAC),将AAH、AIS和MIA归为非侵袭组、IAC归为侵袭组。按7∶3比例将患者分为训练集(n=119,含5例AAH、9例AIS、36例MIA及69例IAC)和验证集(n=51,含1例AAH、3例AIS、22例MIA及25例IAC)。采用单因素及logistic回归分析训练集患者一般资料及病灶CT表现,筛选预测肺亚实性结节侵袭性的独立危险因素并建立CT模型;基于训练集提取及筛选病灶最佳影像组学特征,以之构建影像组学模型。基于CT模型及影像组学模型构建联合模型,并以列线图将其可视化。绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),基于验证集评估各模型诊断效能;以校准曲线评价联合模型的校准程度。结果 CT所示结节长径和最大CT值为预测肺亚实性结节为IAC的CT相关独立危险因素,以之构建CT模型。基于训练集筛选出6个最佳影像组学特征并构建影像组学模型。CT模型、影像组学模型及联合模型预测验证集肺亚实性结节侵袭性的AUC分别为0.772、0.785及0.869;联合模型的AUC高于CT模型(Z=2.336,P=0.019)而与影像组学模型差异无统计学意义(Z=1.925,P=0.054),其预测结果与实际结果的一致性较高。结论 CT影像组学联合CT特征可有效预测肺亚实性结节侵袭性。     

肺结节胸腔镜切除术前微弹簧圈定位相关并发症及其影响因素

目的 观察电视辅助肺结节胸腔镜切除术（VATS）术前定位微弹簧圈相关并发症,并分析其影响因素。方法 回顾性分析160例肺结节患者（160个结节）,均于VATS切除结节前行CT引导下微弹簧圈定位,统计定位术后并发症,分析其影响因素。结果 160例结肺节均以微弹簧圈成功定位,术中26例出现气胸,37例发生肺内出血,未见空气栓塞。所有患者于次日接受VATS,术中均未发现微弹簧圈移位。单因素分析结果显示,患者体位（P=0.04）、结节距胸膜距离（P=0.03）及穿刺次数（P<0.01）与微弹簧圈定位术后发生气胸相关,结节距胸膜距离（P=0.03）与微弹簧圈定位术后发生肺内出血相关。多因素分析结果显示,患者体位、结节距胸膜距离及穿刺次数是微弹簧圈定位术后发生气胸的独立危险因素（P均<0.05）,结节距胸膜距离则是肺内出血的独立危险因素（P=0.01）。结论 肺结节VATS术前微弹簧圈定位可出现气胸和肺内出血,前者与结节距胸膜距离、患者体位及穿刺次数相关,后者仅与结节距胸膜距离相关。     

CT鉴别诊断原发性与继发性肺淋巴瘤

目的 观察CT鉴别诊断原发性肺淋巴瘤(PPL)与继发性肺淋巴瘤(SPL)的价值。方法 回顾性分析接受胸部CT平扫的28例PPL(PPL组)及27例SPL(SPL组)患者,其中18例PPL及16例SPL接受增强扫描,观察病变CT表现;采用单因素分析及多因素logistic回归分析其CT平扫相关征象,筛选鉴别PPL与SPL的独立预测因素,并绘制受试者工作特征(ROC)曲线,评估各指标单独及联合鉴别诊断效能。结果 PPL及SPL均可表现为肺结节、肿块或实变。PPL多为分布于肺外周的单发病变,可见支气管充气征伴扩张;SPL常为多发病变,多伴纵隔/肺门淋巴结肿大及胸腔积液(P均＜0.05)。接受增强CT的18例PPL与16例SPL之间,病变强化方式差异有统计学意义(P=0.04),强化程度及是否存在血管造影征差异均无统计学意义(P均＞0.05)。病变数目、充气支气管征伴扩张及胸腔积液是鉴别PPL与SPL的独立预测因素,其鉴别PPL与SPL的曲线下面积(AUC)分别为0.74、0.68、0.69,三者联合诊断的AUC为0.91。结论 CT所见病变数目、充气支气管征伴扩张及胸腔积液有助于鉴别PPL及SPL。     

基于临床、超声及基因特征列线图预测甲状腺乳头状癌侵袭性

目的 观察基于临床、超声及基因特征的列线图预测甲状腺乳头状癌(PTC)侵袭性的价值。方法 回顾性分析207例PTC患者,根据术后病理所示病灶侵及甲状腺被膜和/或发生患侧颈部淋巴结转移与否分为侵袭组(n=130)及非侵袭组(n=77);对比2组临床、超声及基因特征,筛选PTC侵袭性的危险因素,并以之建立列线图模型,观察其预测PTC侵袭性风险的价值。结果 2组患者年龄,结节最大径、与被膜直线距离、微钙化、数目和分布,以及BRAF V600E基因检测差异均有统计学意义(P均＜0.05)。结节最大径＞1 cm[OR=2.540,95%CI(1.341,4.810),P=0.004]、微钙化[OR=2.276,95%CI(1.203,4.308),P=0.011]、双侧叶多灶[OR=3.414,95%CI(1.578,7.385),P=0.002]及突变型BRAF V600E[OR=2.663,95%CI(1.147,6.182),P=0.023]为PTC侵袭性的独立危险因素。列线图模型预测PTC侵袭性的曲线下面积为0.747[95%CI(0.679,0.815)]。结论 以基于结节最大径、微钙化、数目和分布及BRAF V600E基因检测的列线图预测PTC侵袭性具有一定价值。     

三维重建技术在肺腺癌新分类标准诊断中的价值

目的探讨三维重建技术对肺腺癌新分类标准在术前外科诊断中的应用价值,助力于开发人工智能在肺癌辅助诊疗方面的深度学习模型系统。方法回顾性分析2018年10月至2020年6月我院收治的173例经手术病理证实且肿瘤直径≤2 cm肺磨玻璃结节患者的临床资料,其中男55例、女118例,中位年龄61(28~82)岁。同一患者不同部位肺结节视为独立事件,共纳入181例研究对象。按照病理类型新分类标准,将其分为浸润前病变[不典型腺瘤样增生(AAH)和原位腺癌(AIS)]、微浸润腺癌(MIA)及浸润性腺癌(IAC),利用多平面重建(multiplanar reconstruction,MPR)和容积重建(volume reconstruction,VR)等技术,分析研究三维重建相关参数与肺腺癌不同病理亚型之间的关系及其诊断价值。结果肺腺癌不同病理类型肺结节的直径(P<0.001)、平均CT值(P<0.001)、实性成分比值(P<0.001)、结节类型(P<0.001)、结节形态(P<0.001)、胸膜凹陷征(P<0.001)、空气支气管征(P=0.010)、结节内有无血管出入(P=0.005)、TNM分期(P<0.001)差异均有统计学意义,而结节生长部位差异无统计学意义(P=0.054)。同时还发现随着肺腺癌不同病理亚型侵袭性增加,各组参数显性征象比例也逐渐升高。多因素logistic回归分析结果显示,结节直径和平均CT值或实性成分比值是浸润前病变进展为IAC的独立危险因素。结论三维重建下肺小结节各种影像征象,包括结节直径、平均CT值、实性成分比值、形态、类型、血管出入情况、空气支气管征、胸膜凹陷征对肺腺癌新分类标准的诊断具有重要价值,在临床能够为患者个性化治疗提供指导。     

侵袭性肺腺癌微乳头亚型与淋巴结转移的相关性分析

目的探讨侵袭性肺腺癌中微乳头亚型与淋巴结转移的相关性。方法术后病理检查证实为侵袭性肺腺癌的标本433例,依据IASLC/ATS/ERS分类标准进行病理阅片并确定病理亚型,记录患者的年龄、性别、是否吸烟、肿瘤直径、淋巴结转移、肿瘤分期等信息。结果 433例肺腺癌患者,包含微乳头亚型成分92例,占所有侵袭性肺腺癌的21.2%。包含微乳头亚型成分患者发生淋巴结转移率为43.4%,远高于不包含微乳头亚型组11.7%的淋巴结转移率,两组比较差异有统计学意义(P0.05)。结论在肺腺癌中微乳头病理亚型与淋巴结转移有关,提示预后不良。     

侵袭性肺炎克雷伯菌肝脓肿综合征临床及影像学特征

目的 观察侵袭性肺炎克雷伯菌肝脓肿综合征（IKPLAS）临床及影像学特征。方法 回顾性纳入68例肺炎克雷伯菌肝脓肿（KPLA）患者,根据是否发生肝外侵袭性感染分为IKPLAS组（n=25）及非IKPLAS组（n=43）,比较组间临床资料及CT和/或MRI表现。结果 IKPLAS组患者年龄低于而糖化血红蛋白、D-二聚体均高于非IKPLAS组（P均＜0.05）。IKPLAS组18例、非IKPLAS组6例可见肝静脉血栓性静脉炎,IKPLAS组10例、非IKPLAS组28例可见动脉期脓肿周围异常高灌注,组间差异均有统计学意义（P均＜0.05）。IKPLAS组肝外感染主要累及肺（19/25,76.00%）。结论 IKPLAS患者年龄低于而糖化血红蛋白、D-二聚体高于其他KPLA;较常见肝静脉血栓性静脉炎及肝外感染主要累及肺为IKPLAS影像学特征。     

经皮穿刺微波消融恶性肺肿瘤后发生支气管胸膜瘘的危险因素

目的 分析CT引导下经皮穿刺微波消融恶性肺肿瘤后发生支气管胸膜瘘(BPF)的危险因素。方法 回顾性分析901例接受CT引导下经皮穿刺微波消融治疗的肺恶性肿瘤患者,均于治疗后1、3天接受胸部X线和胸部CT复查,之后按照需要进行影像学检查;根据临床及影像学表现判断有无BPF,以单因素及多因素logistic回归分析发生BPF的危险因素。结果 901例中,11例(11/901,1.22%)发生BPF(BPF组)。单因素分析结果显示,BPF组与非BPF组间,瘤体-胸膜最短距离、消融针道累及胸膜和肺或胸膜腔感染差异均有统计学意义(P均＜0.01);多因素分析结果显示,消融针道累及胸膜[OR=44.80,95%CI(5.40,371.98),P＜0.01]和肺或胸膜腔感染[OR=52.40,95%CI(10.34,265.44),P＜0.01]均为发生BPF的独立危险因素。结论 消融针道累及胸膜和肺或胸膜腔感染为经皮微波消融治疗肺恶性肿瘤后发生BPF的危险因素。     

临床模型预测经导管动脉栓塞治疗急性非静脉曲张性上消化道出血术后30天内再出血

目的 根据急性非静脉曲张性上消化道出血（ANVUGIB）患者临床资料建立logistic模型,观察其预测经导管动脉栓塞（TAE）治疗后30天内再出血的价值。方法 纳入139例接受TAE的ANVUGIB患者,记录TAE成功率及术后30天内再出血率;基于临床资料行单因素及多因素分析,筛选再出血的影响因素,建立临床logistic模型,分析其预测TAE后再出血的价值。结果 TAE技术成功率为95.68%（133/139）。对133例TAE技术成功患者随访30天,其中29例再出血,再出血率21.80%（29/133）。术前凝血功能障碍（OR=3.74,P=0.045）及术前高Rockall评分（OR=1.97,P=0.005）为TAE治疗ANVUGIB后30天内再出血的危险因素,男性（OR=0.19,P=0.007）及术前CT阳性（OR=0.06,P=0.047）为其保护因素。基于上述4个因素建立的logistic模型预测ANVUGIB患者TAE后30天内再出血的敏感度和特异度分别为82.80%和75.00%,曲线下面积为0.817,高于Rockall评分、Blatchford评分及澳洲医药科学家协会65评分（P均<0.05）。结论 基于性别、术前凝血功能障碍情况、Rockall评分及CT表现建立的临床模型有助于预测TAE治疗ANVUGIB后30天内再出血。     

零回波时间3.0T MRI用于检出肺癌结节

目的 观察零回波时间(ZTE)3.0T MRI检出肺癌结节的价值。方法 前瞻性纳入126例肺癌患者(共176个肺结节),以3.0T MR仪行肺部轴位ZTE成像和常规序列成像,包括T1容积内插屏气检查(VIBE)、T2刀锋序列(BLADE)及T2半傅里叶采集单次激发快速自旋回波(HASTE)序列扫描;分析ZTE MRI与CT显示肺结节特征的一致性,观察以不同MR序列检出肺结节的敏感度。结果 176个肺结节中,ZTE MRI检出140个、漏诊36个。ZTE MRI与CT显示肺结节最大径及其实性部分最大径的一致性均好(ICC=0.954、0.943,P均<0.001)且差异较小,显示气管血管束、胸膜凹陷及内部支气管充气征的一致性均好(Kappa=0.894、0.912、0.917),显示结节类型及形状的一致性中等(Kappa=0.661、0.501)。ZTE MRI检出肺结节的敏感度均高于其他单独MR序列(P均<0.05);ZTE与T2-BLADE组合的敏感度均高于其他序列组合(P均<0.05)。结论 ZTE 3.0T MRI检出肺癌结节的效能较好,优于常规MR序列;与T2-BLADE联合可进一步提高其敏感度。     

囊腔类肺癌CT特征分析

目的分析囊腔类肺癌的CT特征。方法回顾性分析经病理证实的24例囊腔类肺癌的CT表现。所有患者均接受平扫,其中4例同期接受增强扫描。结果 24例均为单发病灶。4例病灶CT表现为单纯囊腔,8例表现为囊腔伴周围磨玻璃密度影,7例表现为囊腔伴周围实性密度影,5例囊腔周围同时伴有磨玻璃及实性密度影;囊腔形态呈圆形或类圆形9例,不规则形15例;22例囊壁不光整,2例囊腔壁光整。4例接受CT增强扫描者囊腔周围实性密度影可见中度强化。13例囊腔内可见壁结节,20例囊腔内可见粗细不均的分隔;出现分叶征18例,毛刺征12例,血管集束征9例,胸膜凹陷征10例。结论囊腔类肺癌CT表现具有一定特征性,对囊腔及其周围CT表现进行综合分析有助于进一步明确诊断。     

Computed tomography versus frozen sections for distinguishing lung adenocarcinoma: A cohort study of concordance rate

BackgroundComputed tomography (CT) imaging can help to predict the pathological invasiveness of early-stage lung adenocarcinoma and guide surgical resection. This retrospective study investigated whether CT imaging could distinguish pre-invasive lung adenocarcinoma from IAC. It also compared final pathology prediction accuracy between CT imaging and intraoperative frozen section analysis.MethodsThis study included 2093 patients with early-stage peripheral lung adenocarcinoma who underwent CT imaging and intraoperative frozen section analysis between March 2013 and November 2014. Nodules were classified as ground-glass (GGNs), part-solid (PSNs), and solid nodules according to CT findings; they were classified as pre-IAC and IAC according to final pathology. Univariate, multivariate, and receiver operating characteristic (ROC) curve analyses were performed to evaluate whether CT imaging could distinguish pre-IAC from IAC. The concordance rates of CT imaging and intraoperative frozen section analyses with final pathology were also compared to determine their accuracies.ResultsMultivariate analysis identified tumor size as an independent distinguishing factor. ROC curve analyses showed that the optimal cut-off sizes for distinguishing pre-IAC from IAC for GGNs, PSNs, and solid nodules were 10.79, 11.48, and 11.45 mm, respectively. The concordance rate of CT imaging with final pathology was significantly greater than the concordance rate of intraoperative frozen section analysis with final pathology (P = 0.041).ConclusionCT imaging could distinguish pre-IAC from IAC in patients with early-stage lung adenocarcinoma. Because of its accuracy in predicting final pathology, CT imaging could contribute to decisions associated with surgical extent. Multicenter standardized trials are needed to confirm the findings in this study.     

纯磨玻璃密度浸润性肺腺癌CT表现

目的探讨纯磨玻璃密度(pGGO)结节浸润性肺腺癌的CT特点。方法根据2011年多学科肺腺癌分类(IASLC/ATS/ERS分类),收集经手术病理确诊为肺腺癌并且CT表现为pGGO结节(≤3cm)的88例患者(94个病变),其中浸润性肺腺癌37例(38个病变),结合临床和病理资料,分析结节的瘤肺界面、病灶边缘(分叶、毛刺)、内部结构及邻近结构。结果 38个浸润性肺腺癌结节最大径0.7~3.0cm,平均(1.75±0.46)cm,其中结节直径1cm者3个,1~2cm者25个,2cm者10个。所有结节边界均较清楚,结节出现分叶31个,毛刺11个,空泡征28个,形成空腔5个,胸膜凹陷征14个,血管集束征28个。18个结节局部或整体密度增高,其中局部密度增高12个,整体密度增高6个。手术病理证实贴壁生长腺癌27个,微乳头腺癌2个,腺泡样癌4个,乳头型腺癌2例,实性腺癌3例。结论 pGGO肺腺癌结节中,CT表现为空泡征、瘤肺界面清晰、血管集束征提示浸润性肺腺癌可能。     

Imaging Characteristics in ALK Fusion-Positive Lung Adenocarcinomas by Using HRCT

Objectives: We aimed to identify high-resolution computed tomography (HRCT) features useful to distinguish the anaplastic lymphoma kinase gene (ALK) fusion-positive and negative lung adenocarcinomas.Methods: We included 236 surgically resected adenocarcinoma lesions, which included 27 consecutive ALK fusion-positive (AP) lesions, 115 epidermal growth factor receptor mutation-positive lesions, and 94 double-negative lesions. HRCT parameters including size, air bronchograms, pleural indentation, spiculation, and tumor disappearance rate (TDR) were compared. In addition, prevalence of small lesions (≤20 mm) and solid lesions (TDR ≤20%) were compared.Results: AP lesions were significantly smaller and had lower TDR (%) than ALK fusion-negative (AN) lesions (tumor diameter: 20.7 mm ± 14.1 mm vs. 27.4 mm ± 13.8 mm, respectively, p <0.01; TDR: 22.8% ± 24.8% vs. 44.8% ± 33.2%, respectively, p <0.01). All AP lesions >20 mm (n = 7, 25.9%) showed a solid pattern. Among all small lesions, AP lesions had lower TDR and more frequent spiculation than AN lesions (p <0.01). Among solid lesions, AP lesions were smaller than AN lesions (p = 0.01).Conclusion: AP lung lesions were significantly smaller and had a lower TDR than AN lesions. Spiculation was more frequent in small lesions. Non-solid >20 mm lesions may be ALK fusion-negative.     

A study of high-resolution computed tomography (HRCT) findings of resected small pulmonary nodules 2 cm or less in diameter with reference to the malignant nature

To identify the characteristics of peripheral small lung mass lesions on high-resolution computed tomography (HRCT) and discriminate between malignant and benign, 223 mass lesions 2 cm or less resected surgically were evaluated about following points. 1) Density : 90.7% of lesions with mixed solid and ground-glass opacity (GGO) components were adenocarcinomas. Pure GGO lesions without scale-down between several months were all adenocarcinomas or atypical adenomatous hyperplasia (AAH). Thereby, patients with these findings are good candidates for surgical resection. 2) Spicular or pleural indentation :75.2% (88 of 117 cases) of adenocarcinomas and all squamous cell carcinomas (18 cases) showed these findings, but 26.6% (41 of 154 cases) of positive cases were benign lesion (non-specific inflammation, mycobacterisis, and so on). Accordingly, they are not peculiar to malignancy. 3) Satellite lesion : all lesions with this one showed benign, therefore it was thought that this finding could exclude malignant lesion. Thus, recognition of certain characteristics at HRCT can be helpful in discrimination between small malignant mass and benign mass.     

良性肺结节的临床特点及其诊断和治疗

目的分析良性肺结节(直径≤2 cm)的临床特点，提高肺结节诊断的精确性。 方法收集和分析2013—2018年在大连大学附属中山医院胸外科接受手术治疗的良性肺结节患者的临床资料，并与同期手术的恶性肺结节的影像学特点进行对比。 结果共有良性肺结节患者104例(良性率占22.7%)。病理诊断机化性肺炎43例、肉芽肿17例、错构瘤和非典型腺瘤样增生(AAH)各14例、淋巴结增生7例、炎性假瘤6例、硬化性肺细胞瘤2例、结核性肉芽肿合并AAH 1例。无症状就诊患者39例，主诉胸痛者33例、咳嗽13例、咳嗽咳痰11例、胸闷7例、发热1例；术前观察时间平均7个月(1周～6年)，17个结节有增大或密度增加；26例患者肿瘤标志物轻度增高。CT影像表现：结节形态不规则者19例，具有毛刺征者20例、分叶征11例、胸膜凹陷16例、钙化11例、血管集束征9例、空泡征9例、胸膜增厚8例、支气管通气征7例。与同期手术的354例恶性结节(原发性肺癌)比较发现，良性结节多为实性(P ≤ 0.001)、直径≤10 mm(P ＝ 0.003)；同时胸膜凹陷及血管集束征的发生率较低(P ≤ 0.001；P ＝ 0.013)；良恶性结节均好发于上叶肺。 结论手术切除的良恶性肺结节的影像学特点有相似之处，胸膜凹陷和血管集束征更具鉴别意义。对直径≤1 cm的实性肺结节，应给予更大耐心。     

Pleural lavage cytology immediately after thoracotomy and before closure of the thoracic cavity for lung cancer without pleural effusion and dissemination: Clinicopathologic and prognostic analysis

Background: The significance of intraoperative pleural lavage cytology (PLC) in lung cancer patients without malignant effusion remains undetermined in terms of staging, prognosis, and local management. Methods: PLC was performed both after thoracotomy and before closure of the thoracic cavity in 325 patients with lung cancer without malignant pleurisy. Results: According to the PLC results (positive [+] or negative [−] after thoracotomy/before closure), the patients were classified as follows: group A (−/−), 262 patients; group B (+/−), 19; group C (−/+), 22; and group D (+/+), 22. In comparison with group A, group C showed more advanced stage with aggressive nodal involvement, and group D showed more advanced lung cancer related to pleural and nodal involvement, whereas group B showed characteristics similar to those of group A. The rate of pleural recurrence in group D was the highest (26%). In particular, pleural recurrence was seen in the patients with a relatively large number of adenocarcinoma cells in PLC after thoracotomy. The patients in groups C and D, especially those with adenocarcinoma, showed poorer prognosis, but in a multivariate analysis, PLC status was not an independent prognostic factor. Conclusions: PLC status after thoracotomy provides useful information in the detection of high-risk subgroup for pleural recurrence. Although PLC status is closely associated with survival, its prognostic value is not independent.     

Factores predictores de respuesta completa patológica tras inducción (ypT0N0M0) en cáncer de pulmón no microcítico y resultados a corto plazo: resultados del Grupo Español de Cirugía Torácica Videoasistida (GE-VATS)

IntroductionTo analyze the predictors of pathological complete response (pCR) in not small cells lung carcinoma (NSCLC) patients who underwent anatomical lung resection after induction therapy and to evaluate the postoperative results of these patients.MethodsAll patients prospectively registered in the database of the GE-VATS working group undergone anatomic lung resection by NSCLC after induction treatment and recruited between December 20^th 2016, and March 20^th 2018, were included in the study. The population was divided into two groups: patients who obtained a complete pathological response after induction (pCR) and patients who did not obtain a complete pathological response after induction (non-pCR). A multivariate analysis was performed using a binary logistic regression to determine the predictors of pCR and the postoperative results of patients were analyzed.ResultsOf the 241 patients analyzed, 36 patients (14.9%) achieved pCR. Predictive factors for pCR are male sex (OR 2.814, 95% CI 1.015-7.806), histology of squamous carcinoma (OR 3.065, 95% CI 1.233-7.619) or other than adenocarcinoma (ADC) (OR 5.788, 95% CI 1.878-17.733) and induction therapy that includes radiation therapy (OR 4.096, 95% CI 1.785-9.401) and targeted therapies (OR 7.625, 95% CI 2.147-27.077). Prevalence of postoperative pulmonary complications was higher in patients treated with neoadjuvant chemo-radiotherapy (p = 0.032).ConclusionsMale sex, histology of squamous carcinoma or other than ADC, and induction therapy that includes radiotherapy or targeted therapy are positive predictors for obtaining pCR. Induction chemo-radiotherapy is associated with a higher risk of postoperative pulmonary complications.     

Malignant pleural mesothelioma showing rare morphology indistinguishable from myxofibrosarcoma concomitant with EGFR-mutated lung adenocarcinoma: A case report

Introduction and importancePrimary tumors of the pleura are rare, with malignant mesothelioma being the most common of these neoplasms. Pathological diagnosis of sarcomatoid mesothelioma can be more challenging than that of epithelioid malignant mesothelioma because of its similarities with true sarcomas and restricted or inconsistent expression of mesothelial markers in immunohistochemistry analysis.Presentation of caseHere, we present an unusual case of malignant pleural mesothelioma concomitant with lung adenocarcinoma in a 72-year-old Japanese man, a smoker with no family history of cancer and asbestos exposure. Malignant pleural mesothelioma is composed of epithelial and spindle-shaped cells. Spindle-shaped cells with scant eosinophilic cytoplasm and hyperchromatic nuclei proliferated in abundant myxoid stroma containing thin-walled blood vessels, mimicking myxofibrosarcoma. The loss of BAP1 (BRCA1-associated protein 1) expression, as assessed by immunohistochemistry, and homozygous deletions of CDKN2A, detected using fluorescence in situ hybridization (FISH), were observed in both components. Targeted sequencing revealed that lung adenocarcinoma harbored EGFR mutations, whereas no mutations were detected in either component of biphasic mesothelioma.DiscussionAlthough alcian blue-stained mucins were detected in biphasic mesothelioma subsets, the clinicopathological significance of myxoid stroma in biphasic and sarcomatoid mesothelioma remains largely unknown.ConclusionOur case presented a unique morphology mimicking myxofibrosarcoma in a sarcomatoid component of biphasic mesothelioma; therefore, it raises a question on the clinicopathological significance of myxoid stroma in sarcomatous areas of biphasic and sarcomatoid mesothelioma.