应用纵隔镜手术诊断Ⅰ期胸部结节病

目的 探讨纵隔镜手术在Ⅰ期胸部结节病诊断和鉴别诊断中的应用价值.方法 回顾性分析1999年11月至2007年6月60例临床拟诊Ⅰ期胸部结节病患者的临床资料.所有患者术前行胸部X线片及CT发现肺门和(或)纵隔淋巴结肿大,肺部未见异常表现.以伴有或不伴有纵隔淋巴结肿大的两侧肺门淋巴结肿大为Ⅰ期胸部结节病的典型表现.结果 本组60例患者术后均获得明确的病理诊断.影像学表现典型者33例,纵隔镜检查术后32例获得病理学证实,诊断准确率97%;1例为纵隔淋巴结反应性增生.27例根据影像学表现考虑不典型Ⅰ期胸部结节病的患者,纵隔镜检查术后病理证实17例(63%),另有纵隔淋巴结结核6例,纵隔淋巴结反应性增生2例,转移性鳞状细胞癌以及小细胞癌各1例.全组手术顺利,无手术死亡及并发症.结论 临床及影像学表现典型的Ⅰ期胸部结节病,其临床诊断准确率高,一般不需要行纵隔镜等有创检查以获得病理学证实.     

纵隔镜检查诊断中纵隔肿物的价值

作者对２２例经胸部ＣＴ或ＭＲＩ检查发现有中纵职肿物而一般检查不能确诊的患者施行了标冷纵隔镜术（ＳＣＭ），全部患者均获得明确的病理诊断。其中恶性疾病占４５．５％（１０／２２），良性病变占５４．５％（１２／２２）。恶性疾病中以小细胞未分化癌最为多见，占６０％（６／１０）；良性病变中淋巴结结核最为多发，占７５％（９／１２）。作者复习了纵职镜发展的历史，并对手术适应证和注意事项进行了讨论。     

经颈部纵隔镜检查在胸部疾病诊断中的价值

目的探讨经颈部纵隔镜检查术在胸部疾病诊断中的价值。方法回顾性分析1990年1月-2008年9月施行281例经颈部纵隔镜检查术的临床资料。采用局部浸润麻醉或全身麻醉,经气管前间隙向下方探查气管周围肿物和淋巴结,并进行活检。结果268例获得明确病理诊断,确诊率95.4%（268/281）。术前诊断不明23例全部获得明确病理诊断,恶性肿瘤术前诊断病理符合率56.9%（41/72）,良性病变术前诊断病理符合率87.4%（104/119）。结论经颈部纵隔镜检查术对单独或伴有纵隔内肿块的胸部疾病是一种有效的检查方法,对于诊断不明的单纯纵隔淋巴结肿大者尤其适合,对肺癌伴有纵隔淋巴结肿大或纵隔肿瘤者可选择应用。     

电视纵隔镜手术128例

目的探讨电视纵隔镜检查术（video-mediastinoscopy，VM）在肺癌术前分期、纵隔肿物诊断和恶性胸腔积液诊治中的价值。方法采用全麻单腔螺纹气管插管，48例行颈部纵隔镜术，33例行胸骨旁纵隔镜检查术，47例行经肋间纵隔镜术。结果125例经电视纵隔镜术后确诊：肺腺癌38例，肺转移性低分化鳞癌33例，结核9例，淋巴结炎症8例，肺小细胞癌7例，胸腺鳞状细胞癌6例，非霍奇金淋巴瘤5例，纵隔神经母细胞瘤4例，胸腺瘤4例，胸膜间皮瘤3例，霍奇金淋巴瘤2例，后纵隔神经鞘瘤2例，结节病1例，胸腺增生1例，类癌1例，中纵隔原始神经外胚叶肿瘤1例。1例电视纵隔镜检查纵隔淋巴结为反应性增生，行左下肺叶切除，病理为鳞癌。2例术前纤维支气管镜病理确诊左下肺鳞癌，电视纵隔镜检查右气管旁淋巴结转移。术中发生气胸1例、出血1例、喉返神经麻痹和切口感染各2例。结论电视纵隔镜术不但是肺癌术前病理分期、纵隔疾病的重要检查方法，而且也是诊治恶性胸腔积液的简便方法。     

纵隔疑难疾病的纵隔镜诊断和鉴别诊断

目的　探讨纵隔镜手术在纵隔疑难疾病诊断中的应用价值。　方法　自 1999年 11月至2 0 0 2年 2月为 35例纵隔疑难疾病患者进行了纵隔镜手术 ,对胸部CT等检查发现的纵隔病变进行活检 ,获取气管周围、胸骨后、隆突下以及双侧肺门等部位的肿物组织送病检。　结果　本组除 1例外全部获得明确病理诊断 ,确诊率 97% (34/ 35 )。其中恶性病变 18例 (5 2 9% ) ,良性病变 16例 (47 1% )。术前术后诊断符合率 4 7 1% (16 / 34) ,术前误诊率 5 2 9%。术前误诊的病例中以良性病变多见 ,本组 16例良性病变中 ,有 6 2 5 % (10 / 16 )的病人术前误诊为恶性肿瘤。纵隔镜手术后发生声音嘶哑 1例 ,并发症发生率为 2 9% (1/ 35 )。无围手术期死亡。　结论　纵隔镜手术 ,可使一般方法难以确诊的纵隔疾病获得明确病理诊断 ,且具有创伤小、安全、取材可靠等优点 ,因此应作为纵隔疑难疾病诊断的常规手段。     

纵隔镜检查术165例临床分析

目的 探讨纵隔镜检查术在胸部疾病诊断及确定手术适应证中的价值。方法 对1979－2000年,有选择性地施行纵隔镜检查术的165例患者的临床资料进行回顾性分析。所有患者皆采用局部浸润麻醉（个别病例加用静脉基础麻醉）下,经气管前间隙向下方探查气管周围肿物和淋巴结,并进行活检。结果 有125例诊断符合（11例未能明确诊断和8例肺癌患者虽纵隔镜检查阴性但未经手术证实不计入）,21例诊断不符合。诊断符合率为85．6％（125／146）。其中20例纵隔淋巴结阳性的肺癌患者和7例经纵隔镜诊断恶性淋巴瘤者避免了开胸手术。结论 纵隔镜检查术,对累及纵隔淋巴结的疾病或紧邻纵隔的胸部疾病是一种有效的检查方法,对于诊断不明的单纯纵隔淋巴结肿大者尤其适合。对肺癌伴有纵隔淋巴结肿大或纵隔肿瘤者可选择应用。     

自行组配电视纵隔镜诊断纵隔疑难病灶的临床价值

目的 总结应用自行组配电视纵隔镜行纵隔镜检查诊断纵隔疑难病灶的临床经验,探讨其应用价值,为缺少纵隔镜设备情况下如何整合现有微创资源开展纵隔镜检查术提供借鉴.方法 回顾性分析2007年11月～ 2013年3月127例电视纵隔镜手术的临床资料.其中2011年10月前应用直达喉镜、活检钳和10 mm 0.胸腔镜自行组配电视纵隔镜完成69例（自组配组）,2011年11月后应用Storz电视纵隔镜完成58例（Storz组）.结果 全组无手术死亡.2组手术时间无明显差异（P＞0.05）.并发出血3例（填塞压迫止血1例,开胸止血2例）,喉返神经损伤2例,并发症发生率3.9％,两组间差异无显著性[4.3％ （3/69） vs.3.4％ （2/58）,Х^2=0.000,P=1.000].自组配组明确病理诊断率98.6％（68/69）,Storz组100％（58/58）,两组差异无显著性（P=1.000）.9例术前合并上腔静脉综合征,其中7例同期经股静脉置入上腔静脉支架（自组配组4例,Storz组3例）,临床症状明显缓解.71例纵隔镜检查术前拟诊为恶性肿瘤,术后病理确诊为恶性肿瘤50例,良性病变21例,术前临床诊断准确率为70.4％ （50/71）;56例拟诊为良性病变,术后病理诊断良性病变37例,恶性肿瘤19例,术前临床诊断准确率66.1％（37/56）.结论 电视纵隔镜手术微创、安全,是纵隔疑难疾病诊断的可靠方法,利用现有器械和设备自行组配的电视纵隔镜系统,可用于纵隔疑难疾病的诊断.     

支气管内超声引导针吸活检术诊断胸部疾病

目的 探讨EBUS-TBNA在诊断胸部疾病中的应用价值.方法 回顾性分析2009年9月至2011年8月343例经EBUS-TBNA术检查患者资料,男219例,女124例;年龄(59.4±13.6)岁.其中影像学可疑或已明确肺癌,并伴有纵隔或肺门淋巴结肿大208例;不伴有肺内占位的纵隔和(或)肺门淋巴结肿大或纵隔占位94例;邻近大气道的肺实质内占位41例.结果 患者胸部病变短径(1.94±1.01) cm,穿刺胸部病变(1.77±0.86)个/例,穿刺(4.71±2.69)次,每处病变平均穿刺2.66次.本组EBUS-TBNA诊断纵隔和(或)肺门良、恶性病变总的敏感性95.6％(238/249例)、特异性100％( 94/94例)、阳性预测值100％(238/238例)、阴性预测值89.5％(94/105例)、准确性96.8％(332/343例).208例明确或可疑肺癌患者中151例经EBUS-TBNA诊断纵隔淋巴结转移,4例为结核,2例为Ⅱ期结节病;51例EBUS-TBNA阴性患者中37例接受进一步手术,32例证实为真阴性.EBUS-TBNA对本组188例肺癌患者纵隔淋巴结分期的敏感性96.8％(151/156例)、特异性100.0％(32/32例)、准确性97.3％(183/188例),阳性预测值100.0％(151/151例)、阴性预测值86.5％(32/37例).94例纵隔和(或)肺门淋巴结肿大或纵隔占位患者中22例恶性病变,73例良性病变中有23例诊断为淋巴结反应性增生,其中有13例接受进一步手术,6例为假阴性.EBUS-TBNA诊断本组纵隔病变良、恶性的敏感性88.0％(22/25例)、特异性100％(73/73例)、阴性预测值95.9％(70/73例)准确性97.9％(92/94例).EBUSTBNA对本组纵隔恶性和良性病变诊断的准确率分别为88.0％(22/25例)和95.9％(70/73例).41例邻近大气道的肺实质内占位中恶性33例;8例EBUS-TBNA阴性,其中4例经进一步手术证实为假阴性.EBUS-TBNA诊断大气道旁肺实质内占位中的敏感性89.2％(33/37例)、准确性90.2％(37/41例).全组病例无穿刺相关并发症发生.结论 EBUS-TBNA术对于肺癌的病理分期可靠,诊断邻近大气道的肺门或纵隔占位等胸部疾病安全、有效.     

左前纵隔切开术的临床应用

目的探讨左前纵隔切开术在不明原因的纵隔淋巴结肿大和前纵隔占位诊断中的价值. 方法采用左前纵隔切开入路,对32例胸部CT等检查发现的不明原因纵隔淋巴结肿大或纵隔占位进行活检术. 结果 32例均获得明确的病理诊断,确诊率达100%(32/32).3例心包积液同期行心包开窗术,心包填塞症状缓解.4例同期行肺活检术.本组手术时间(48±15) min,术中出血量(40.6±23.5) ml,术后住院(3.6±1.4) d,无手术死亡及术后并发症发生. 结论左前纵隔切开术对于常规颈部纵隔镜难以到达的第5、6组淋巴结肿大或不明原因的纵隔占位是一种安全有效的诊断手段,并可同时尝试进行诸如肺活检术、心包开窗术等一些简单的治疗.     

电视纵隔镜术诊治胸部疾病76例

目的探讨电视纵隔镜检查在肺癌的术前分期、纵隔肿物、恶性胸腔积液诊治中的应用。方法76例患者中行颈部纵隔镜术38例,胸骨旁纵隔镜术16例,经肋间纵隔镜术22例。结果经纵隔镜检查确诊为腺癌21例,转移性低分化鳞癌18例,结核6例,胸腺鳞状细胞癌5例,非何杰金淋巴瘤5例,肺小细胞癌4例,胸腺瘤3例,纵隔神经母细胞瘤3例,何杰金淋巴瘤2例,胸膜间皮瘤2例,神经鞘瘤1例,胸腺增生1例,原始神经外胚叶肿瘤1例,淋巴结炎症1例,反应性增生1例。2例术前纤维支气管镜病理诊断为左肺下叶鳞癌,经电视纵隔镜检查确诊为右气管旁淋巴结转移。结论电视纵隔镜术不但是肺癌术前病理分期的重要检查方法,还可作为纵隔疾病和恶性胸腔积液诊治的方法之一。     

Use and prognostic value of staging mediastinoscopy in non-small-cell lung cancer

One hundred sixty patients had preoperative mediastinoscopy, resection of the primary tumor, and complete mediastinal lymphadenectomy for non-small-cell carcinoma of the lung. Minimum follow-up was 24 months (mean 40 months). Postoperative staging based on histologic examination of the specimen of the lung and mediastinal lymphadenectomy categorized 59 patients in stage I, 28 in stage II, and 73 in stage III (20 T3N0, 12 T3N1, 29 T1 or T2N2, and 12 T3N2). The sensitivity rate of cervical mediastinoscopy for detection of mediastinal node metastasis was 48.7%. False-negative results of mediastinoscopy occurred in 21 of 41 patients with normal mediastinoscopy: unreachable nodes in eight patients, sampling error of reachable nodes in 11 patients, and error on frozen section in two patients. Eleven of 65 patients with clinical stage I disease and normal mediastinum on chest roentgenogram had mediastinal node involvement; only three were detected by mediastinoscopy, which resulted in a low sensitivity rate (27.3%) and a high rate of unnecessary mediastinoscopy (62/65 patients). The sensitivity of mediastinoscopy increased as the amount of disease present, as measured by the clinical stage of disease or positive gallium 67 scan of mediastinum, increased. Eleven of 29 patients with T1 to T2N2 disease discovered at mediastinoscopy had similar survival rates compared with 18 of 29 patients who had a normal mediastinoscopy examination and mediastinal node involvement discovered at thoracotomy.     

Mediastinal ultrasonography for the assessment of mediastinal lymph node metastases in lung cancer patients

Using an ultrasonic probe inserted into the mediastinum during cervical mediastinoscopy, mediastinal ultrasonography (USM) was performed on 63 patients with lung cancer. The patients with a small peripheral mass of less than 2 cm in diameter, according to the chest X-ray results, and with mediastinal lymph nodes smaller than 1 cm in their short axes as determined by computed tomography (CT), were excluded from this study. An analysis of the areas under the receiver operating characteristic curves derived from CT and USM showed that USM was superior (P=0.043) to CT in terms of the diagnosis for mediastinal lymph node metastases, when the short axis dimension of mediastinal lymph nodes was employed for the diagnosis of metastases. The reason for this is that 97% of the mediastinal lymph nodes imaged by USM were located vertically along the body axis of the patient, and hence USM imaged the true short axis of the node in many cases. Our results indicate that USM is useful for performing a safe biopsy of lymph nodes during mediastinoscopy as well as for obtaining a clear imaging of the subcarinal nodes, which are inaccessible by normal cervical mediastinoscopy.     

Results of preoperative mediastinoscopy for small cell lung cancer

BACKGROUND: The significance of mediastinoscopy for small cell lung cancer is unclear owing to the small number of surgical cases. METHODS: To determine the N component of the TNM staging system, computed tomographic findings and the results of mediastinoscopy were compared with the pathologic examination of surgical specimens. RESULTS: Four cases among 37 patients (10.8%) were determined as inoperable by mediastinoscopy because of mediastinal lymph node metastasis. A thoracotomy was performed in 33 patients. Six patients (18.2%) who had been judged to have no metastasis by mediastinoscopy were found to have N2 disease after examination of the surgical specimens. In the identification of all mediastinal metastases, mediastinoscopy was 40.0% sensitive, 100% specific, and 83.8% accurate. When the superior mediastinal, paratracheal, pretracheal, tracheobronchial, and subcarinal lymph nodes were defined as approachable nodes, mediastinoscopy was 66.7% sensitive, 100% specific, and 94.6% accurate in the evaluation of these restricted nodes. Four cases among 8 patients with cN1 lesions resulted in a designation as pN2. CONCLUSIONS: Mediastinoscopy is useful for the diagnosis of an approachable mediastinal lymph node in small cell lung cancer cases. This exploration is necessary for patients with small cell lung cancer who are diagnosed as cN1 before thoracotomy.     

Mediastinoscopy vs. anterior mediastinotomy in the diagnosis of mediastinal lymphoma: a randomized trial.

We selected 95 patients with mediastinal adenopathy and no signs of goiter, myasthenia gravis or mediastinal involvement by other disease. All patients underwent, for screening purposes, transthoracic fine needle aspiration biopsy based on chest x-ray and CT findings. Patients were then subdivided into 4 groups. One group of 22 patients with prevalent anterior mass localization underwent anterior mediastinotomy. One group of 19 patients with prevalent middle mediastinal mass localization underwent cervical mediastinoscopy. Two other groups of 27 patients each with both anterior and middle mediastinum localization randomly underwent anterior mediastinotomy or mediastinoscopy. Fifty-one Hodgkin's and 44 non-Hodgkin's lymphomas were diagnosed in total. In 11 cases (11.57%), median sternotomy (2) or thoracotomy (9) were necessary for establishing the final diagnosis. The overall diagnostic accuracy was 80.43% for cervical mediastinoscopy and 95.91% for anterior mediastinotomy. The statistical analysis performed on all patients showed a significant difference (chi 2 = 5.56, P less than 0.025, df = 1) between the two procedures.     

电视纵隔镜临床应用的初步体会

目的：探讨电视纵隔镜手术在临床应用中的价值。方法：回顾性总结2001年9月－2002年9月54例经电视纵隔镜手术患者的临床资料,其中颈部纵隔镜手术44例,胸骨旁纵隔镜手术6例,颈部加胸骨旁纵隔手术4例。术前未获得明确病理诊断的纵隔疾病18例;高度怀疑或已明确诊断为肺癌且影像学显示纵隔淋巴结肿大（直径＞1．0cm）者36例。结果：术前未获病理诊断的18例患者,经电视纵隔镜检查后17例取得明确诊断,确诊率为94．4％（17／18）;高度怀疑或病理已确诊为肺癌的36例,电视纵隔镜检查证实肿瘤纵隔淋巴结转移（阳性）22例,未见纵隔淋巴结转移（阴性）14例。阳性者放弃手术,予以化疗。阴性者均中转开胸行肺叶切除或肺楔型切除加纵隔淋巴结清扫。术后病理证实肺癌11例（纵隔淋巴结未见转移,与纵隔镜检查结果相符）,肺结核球、炎性假瘤和错构瘤各1例。本组纵隔镜手术后患者并发症发生率及病死率均为0。结论：电视纵隔镜手术更安全、可靠,可作为纵隔疑难疾病诊断和明确肺癌术前分期的常规方法。     

Can FDG-PET reduce the need for mediastinoscopy in potentially resectable nonsmall cell lung cancer?

BACKGROUND: Few fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) nonsmall cell lung cancer (NSCLC) trials have had sufficient patients to adequately evaluate PET for mediastinal staging. We question whether once PET is performed, is mediastinoscopy necessary? METHODS: We performed a 5-year retrospective analysis of operable patients with known or suspicious NSCLC. Standard PET techniques were used. Inclusion criteria were (1) surgical mediastinal nodal sampling by mediastinoscopy within 31 days of the PET and (2) definitive diagnosis. RESULTS: There were 237 patients who met the evaluation criteria; ninety-nine patients with NSCLC and 138 with suspicious lesions (137 men and 100 women; aged 20 to 88 years). The PETs were performed from 0 to 29 days before mediastinoscopy (median, 7 days). The standardized uptake value for the primary lesion was 0 to 24.6 (7.9+/-5.0). Nine primary lesions had no FDG uptake (1 benign, 8 NSCLCs). Seventy-one patients (31%) had mediastinal PET positive disease, and 44 patients (19%) had histologic positive mediastinal disease; N2 41 patients (17%) and N3 9 patients (4%). In 6 patients (3%), the initial frozen sections were negative, but PET positivity encouraged further biopsies that were positive for cancer. The PET sensitivity was 82%, specificity 82%, accuracy 82%, negative predictive value 95%, and positive predictive value was 51%. All primary lesions with a standardized uptake value less than 2.5 and a negative mediastinal PET were negative histologically (n = 29). Logistic regression analysis resulted in 100% specificity for PET in this group. CONCLUSIONS: In NSCLC PET may reduce the necessity for mediastinoscopy when the primary lesion standardized uptake value is less than 2.5 and the mediastinum is PET negative. Accepting this approach in our patient population, the need for mediastinoscopy would have been reduced by 12%.     

The selection of patients with bronchogenic carcinoma for mediastinoscopy.

The records of 112 patients treated at the Ochsner Foundation Hospital with the diagnosis of bronchogenic carcinoma were reviewed. A new concept for defining the location of central versus peripheral tumors is presented. Criteria important in selection of patients for whom mediastinoscopy is likely to be helpful are cell type, location (peripheral versus central), and radiographic evidence of mediastinal metastasis. The size of the tumor is not a useful criterion except possibly for squamous cell lesions. A high incidence of mediastinal metasis was found associated with central tumors (63 to 100 per cent) of all cell types and with peripheral lesions (63 per cent) of undifferentiated cell types. A relatively low incidence of mediastinal metasis was associated with peripheral asenocarcinomas or squamous cell tumors. We would, therefore, recommend mediastinoscopy for all patients with central lesions and those patients with peripheral lesions of an undifferentiated cell type. When correlated with radiographic findings, only 4.6 per cent of peripheral carcinomas of a differentiated cell type with a radiographically normal mediastinum were found to produce mediastinal metastases, and mediastinoscopy is not recommended. In patients with peripheral tumors of indeterminate cell type, a decision for mediastinoscopy may be influenced by other factors such as the operative risk of a thoracotomy and location of the primary tumor within the lung.     

Should aggressive surgery ever be part of the management of small cell lung cancer?

CMT with surgery and chemotherapy is feasible, the toxicity is manageable, and postoperative morbidity and mortality rates are acceptable. Patient selection is important, and the results of the LCSG trial indicate that surgical resection will not benefit most patients who have limited SCLC. The chances of long-term survival and cure are strongly correlated with pathologic TNM stage. Consideration of surgery for patients who have SCLC should be limited to those with stage I disease and perhaps some patients with stage II tumors. Therefore, before surgery is undertaken, patients should undergo extensive radiologic staging with CT, MRI, and perhaps even positron emission tomographic scanning and mediastinoscopy, even if the radiologic assessment of the mediastinum is negative. Surgery may be considered for patients with T1-T2 NO SCLC tumors, and whether it is offered as the initial treatment or after induction chemotherapy remains controversial [40,43]. If SCLC is identified unexpectedly at the time of thoracotomy, complete resection and mediastinal lymph node resection should be undertaken, if possible. Chemotherapy is recommended postoperatively for all patients, even those with pathologic stage I tumors. Surgery likely has very little role to play for most patients with stage II disease and virtually no role for patients with stage III tumors. Even though chemotherapy can result in dramatic shrinkage of bulky mediastinal tumors, the addition of surgical resection does not contribute significantly to long-term survival for most patients, as shown conclusively by the LCSG trial. The final group of patients who may benefit from surgical resection are those with combined small cell and non-small cell tumors. If a mixed-histology cancer is identified at diagnosis, the initial treatment should be chemotherapy to control the small cell component of the disease, and surgery should be considered for the non-small cell component. For patients who demonstrate an unexpectedly poor response to chemotherapy, and for patients who experience localized late relapse after treatment for pure small cell tumors, a repeat biopsy should be performed. Surgery may be considered if residual NSCLC is confirmed.     

Mediastinoscopy in the surgical management of lung carcinoma.

Up to December 1973, we had performed 100 mediastinoscopies for lung carcinoma. Fifty-two were positive and 48 negative. In 80 cases there was clinical or radiological suspicion of mediastinal invasion. With radiological evidence of mediastinal node involvement exploration was positive in 32 out of 35 cases, when chest radiography findings were equivocal in 19 out of 45, and when radiology of the mediastinum was normal in only one of 20 cases. Mediastinoscopy was more frequently positive when the carcinoma was oat-cell or anaplastic. Of 48 patients with negative biopsies, 41 were explored. In 26 the carcinoma extended beyond the lung. In 1973 we circularized 83 thoracic surgeons concerning (1) the use of mediastinoscopy for patients with lung carcinoma assessed for surgery, (2) the significance of mediastinal node involvement, (3) the results of radiotherapy alone in patients rejected for surgery, and (4) the survival rate in patients with positive mediastinal nodes treated with surgery alone or together with radiotherapy. The replies to the questionnaire are summarized. The authors emphasize the usefulness of mediastinoscopy but state that care must be taken when deciding to withhold operation for a possible cure.