(Chest. 2001;120:1037-1038.)

Fine-Needle Aspiration and Tumor Seeding
Mehmet Ali Bedirhan, MD and Akif Turna, MD
  Istanbul, Turkey

Correspondence to: Akif Turna, MD, Cami Sok, Muminderesi Yolu, Emintas Camlik Sit, No:32/22, Sahrayicedid, Kadikoy 81080 Istanbul, Turkey; e-mail: aturna{at}turk.net

To the Editor:

We read with great interest the article by Sawabata and associates1 in CHEST (October 2000). The authors present data of a study concerning the potential of malignant cell spread with fine-needle aspiration. Although physicians in some institutions perform fine-needle aspiration routinely and safely in order to obtain histologic diagnosis of thoracic masses with a high rate of accuracy,2 a number of centers do not utilize this method because of possible complications, such as seeding and pneumothorax, especially in patients with COPD. We would like to express a few of our comments on that study.

Firstly, concerning the utilized model of the study, the lung was deflated during and after fine-needle aspiration. Therefore, there is a lack of a counter-balancing effect against the chest wall and a lack of sealing function against the shedding possibility of tumor cells. Since the opposed tissue pressure created by inflated airways and alveoli was decreased in a deflated lung, theoretically tumor cells might anticipate less intercellular pressure of extracellular matrix; therefore, the possible chance for tumor cells to exfoliate outside the lung could be suggested to be higher than that of living lung. That hypothesis could have been tested by comparison of the presence of tumor cells in the pleural irrigation fluid from the fine-needle aspirated deflated and artificially reinflated specimens. We think that that would be the necessary negative control of the study group.

In the study, it was reported that the number of spilled tumor cells was found to be higher, but increased tumor cell shedding does not necessarily result in successful implantation of the tumor cell population because of the resistance of immune system of the host against tumor cells as proposed by the "immune surveillance" theory.3 In order to test this possibility, aspiration tracts could be pathologically examined. Implantation of tumor cells has been known to be extremely rare, such as 1 in 4,000 transthoracic needle biopsy procedures,4 and has been the subject of a few case reports in medical journals.

This study also inspired us to search for evidence of poorer survival in inoperable stage-matched patients who underwent fine-needle aspiration for diagnosis. We were unable to find any study on this respect. For this reason, we think it is unlikely that needle aspiration has a perilous tumor seeding effect in terms of tumor implantation risk in those patients. We are also grateful for that hypothesis-creating innovative study, which could be a basis of further studies.

References


1. Sawabata, N, Mitsunori, O, Maeda, H (2000) Fine-needle aspiration cytologic technique for lung cancer has a high potential of malignant cell spread through the tract. Chest 118,936-939[Abstract/Free Full Text]
2. Kosar, F, Altin, S, Kiyik, M, et al (1996) Transthoracic fine needle aspiration in evaluation of chest lesions suspicious for malignancy: advances in imaging guidance [abstract] Eur Respir J 9,57S
3. Bast, RC, Mills, GB, Gibson, S, et al (1997) Tumor immunology. Holland, JF Bast, RC Morton, DLet al eds. Cancer medicine ,207-242 Williams & Wilkins (Baltimore, MD).  
4. Nordenstrom, B, et al (1973) Dissemination of cancer cells by needle biopsy of lung [letter] Thorac Cardiovasc Surg 65,671

Fine-Needle Aspiration and Tumor Seeding
Noriyoshi Sawabata, MD, FCCP
  Toneyama National Hospital Osaka, Japan



Correspondence to: Noriyoshi Sawabata, MD, FCCP, Division of Surgery, Toneyama National Hospital, 5-1-1 Toneyaman Toyonaka, Osaka, 560-8552 Japan; e-mail: nori{at}toneyama.hosp.go.jp

To the Editor:

I appreciate the response to our article1 concerning the potential of malignant cell spread following fine-needle aspiration cytology (FNAC) from Dr. Bedirhan and Dr. Turna. They pointed out the dissociation between an in vivo and ex vivo lung. As they said, the inflated lung over the tumor can protect against the spread of malignant cells through the tract following FNAC. However, most of the tumors that underwent FNAC were peripherally located and associated with pleural indentation. Thus, the lung over the tumor does not seem to be completely inflated. And so I believe the possibility of spreading tumor cells is similar between an in vivo and ex vivo lung.

I also believe in the "immune surveillance theory." Effusion-associated lymphocytes are revealed to have depressed cellular function in the malignant effusion with lung cancer.2 And so it is speculated that the spread of malignant cells has a low potential of implantation. Surgical patients with lung cancer have a good performance status and may have a normal immune function. We have performed a retrospective study,3 which revealed the technique did not affect relapse and survival. By contrast, patients with advanced lung cancer may have a depressed immune system. Therefore, it is important to search for evidence of pleural carcinomatosis and poorer survival in inoperable patients with advanced lung cancer.

To summarize our opinion, FNAC has the potential to seed malignant cells that rarely implant among operable patients, but the possibility of implantation is controversial among inoperable patients with advanced lung cancer.

References


1. Sawabata, N, Ohta, M, Maeda, H (2000) Fine-needle aspiration cytologic technique for lung cancer has a high potential of malignant cell spread through the tract. Chest 118,936-939[Abstract/Free Full Text]
2. Chen, YM, Tang, WK, Ting, CC, et al (1997) Cross regulation by IL-10 and IL2-/IL12 of the helper T cell and the cytolotic activity of lymphocytes from malignant effusion of lung cancer patients. Chest 112,960-966[Abstract/Free Full Text]
3. Sawabata N, Maeda H, Ohta M. Operable non-small cell lung cancer diagnosed by transpleural techniques: do they affect relapse and prognosis? Chest 2001 (in press)    

Chest, Vol 102, 313-315, 1992



ARTICLES



Implantation metastasis of carcinoma after percutaneous fine-needle aspiration biopsy

N Voravud, DM Shin, RH Dekmezian, I Dimery, JS Lee and WK Hong  
Department of Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston.

Implantation of malignant cells along the needle tract is an extremely rare  but potential complication following percutaneous needle aspiration biopsy  of malignant lesions. Percutaneous fine-needle aspiration biopsy (FNAB) has  recently received more attention for cytologic diagnosis of bronchogenic  carcinoma because of its high diagnostic yield, simplicity, and low  morbidity. On the other hand, dissemination of cancer cells by needle  aspiration biopsy can change a potentially resectable localized lung cancer  to an unresectable one. We report two cases: one patient underwent FNAB of  a metastatic left adrenal mass that seeded a paraspinal muscle implantation  of malignant cells that subsequently developed a tumor mass, and the second  patient had tumor cell implantation in the chest wall after FNAB of a  pleural- based adenocarcinoma of the lung. The theoretical and practical  importance of tumor cell spread along the needle tract is discussed.  Because of its rare incidence, however, this complication should not affect  the use of needle aspiration biopsy in bronchogenic carcinoma, although  care should be undertaken during the procedure.    

Lung Cancer Implantation in the Chest Wall Following Percutaneous Fine  Needle Aspiration BiopsyTakeshi Yoshikawa1, Junji Yoshida1, Mitsuyo  Nishimura1, Tomoyuki Yokose2, Yutaka  Nishiwaki1, Kanji Nagai1
1Department of Thoracic Oncology, National Cancer Center  Hospital East and 2Pathology Division, National Cancer Center  Research Institute East, Kashiwa, Chiba, Japan
Received April 6, 2000; accepted August 15, 2000

We describe a 70-year-old man with lung cancer implantation in the chest wall  following percutaneous fine needle aspiration biopsy. He underwent lobectomy  after percutaneous transthoracic fine needle aspiration biopsy using a 19-gauge  needle. Twenty-six months after the biopsy, he noticed a hard subcutaneous tumor  at the biopsy site in the chest wall. Ribs and intercostal muscles were  resected. The primary lung tumor and the chest wall tumor were histologically  identical, but were not contiguous to each other. We concluded that the  subcutaneous tumor was due to needle biopsy implantation. This complication is  extremely rare, but open biopsy should always be considered as a possible  alternative. During the procedure, care must be taken with the least chance of  implantation and patients should be observed carefully after needle  biopsy.
Key words: neoplasm seeding - needle biopsy - lung neoplasms
INTRODUCTIONFine needle aspiration biopsy (FNAB) in patients with a pulmonary nodule is a  reliable and simple diagnostic procedure (1,2). Malignant cell implantation is a potential, but extremely  uncommon complication (1,3,4). We describe a case of lung cancer with cancer implantation  in the FNAB needle tract.
CASE REPORTA 70-year-old man underwent left lower lobectomy and lymph node dissection  for lung cancer in January 1997. Preoperative transbronchial lung biopsy had  failed to show evidence of malignancy, but percutaneous transthoracic FNAB of  the lung lesion through the left posterior chest wall using a 19-gauge needle in  November 1996 yielded a diagnosis of moderately differentiated adenocarcinoma.  The postoperative pathological diagnosis was moderately differentiated  adenocarcinoma (Fig. 1), T3N0M0, stage IIB (5). The cancer had invaded the elastic layer of the parietal  pleura, which was resected together with the lower lobe, but had not invaded  either the ribs or intercostal muscles.

[img][/img]
Figure 1. Microscopic examination of the primary lung cancer with  hematoxylin-eosin stain.

In January 1999, 26 months after the FNAB, he noticed a hard subcutaneous  tumor in the left posterior chest wall. The tumor was located at the FNAB site  and distant from the thoracotomy incision. It was 3 cm in diameter, fixed to the  eighth and ninth ribs, firm and painless. CT scan of the chest indicated that  the mass was in the subcutaneous layer and in the previous FNAB needle tract  (Fig. 2a and b). FNAB of the tumor had demonstrated adenocarcinoma.  There was no evidence of distant metastasis. We speculated that the mass was  lung cancer implantation resulting from the previous FNAB.

[img][/img]
Figure 2. (a) Chest CT scan before the first operation, showing the  primary lung tumor (arrow) in the left lower lobe. (b) Chest CT scan before the  second operation, showing the subcutaneous tumor (arrow) at the FNAB site.

The tumor, overlying skin, eighth and ninth ribs and intercostal muscles were  surgically resected 29 months after the first surgical intervention. The chest  wall defect was restored with a sheet of Marlex mesh (Davol, Cranston, RI, USA).  The postoperative course was uneventful and he was discharged 9 days after the  operation. The patient is doing well with no signs of recurrence 6 months after  resection. Pathologically, the tumor was diagnosed as moderately differentiated  adenocarcinoma without periosteal invasion (Figs 3 and 4). As the primary lung tumor and the chest wall tumor were  histologically identical but not contiguous and the chest wall tumor was located  precisely at the FNAB site, we concluded that the chest wall tumor was FNAB  implantation.

[img][/img]
Figure 3. Microscopic examination of the chest wall tumor with  hematoxylin-eosin stain (low magnification view).


[img][/img]
Figure 4. Microscopic examination of the chest wall tumor with  hematoxylin-eosin stain (high magnification view). The specimens from the  primary lung cancer (Fig. 1) and chest wall tumor (Fig. 4) were histologically identical.

DISCUSSIONFNAB is a well-established technique for definitive diagnosis of tumor  because of its high diagnostic yield, simplicity and low morbidity (1,2). FNAB in the lung may be complicated by pneumothorax,  hemorrhage, infection and air emboli. Tumor cell implantation along the needle  tract is an extremely rare but potential complication of this technique (1,3,4).
These complications are more likely to follow the use of cutting needles or  large-bore needles (4), because such needles yield larger stromal fragments,  resulting in a more severe visceral injury. Tumor spread along the needle tract  following FNAB has rarely been reported (1,6,7). Sinner reported only one case of FNAB-related tumor seeding  in a total of 1264 patients (0.08%) (1). Lalli et al. reported more than 1500 procedures without a  single incidence of needle tract implantation (3). Harrison et al. reported that two patients (3%) suffered  from needle tract implantation after FNAB, although they had only 66 patients in  their series (8). Our case is the only one in our institution in approximately  900 needle biopsy cases during the 7-year period from January 1993 to January  2000.
Totally effective prevention and management of tumor cell implantation  following FNAB remains undetermined. Wolinsky and Lischner (9) performed immediate radiotherapy after needle biopsy to  prevent tumor implantation, but nevertheless one patient in their series  developed tumor implantation in the chest wall. Seyfer et al. (7) reported a case of chest wall implantation of pulmonary  adenocarcinoma after FNAB, successfully managed by aggressive chest wall  resection and immediate reconstruction with a rectus abdominis musculocutaneous  flap. In our case, we performed tumor resection including the skin, ribs and  intercostal muscles, as no other lesions were detected, with no recurrence so  far.
Because of its rare incidence (1), this complication should not affect the use of FNAB in lung  cancer patients. Wolinsky and Lischner concluded that FNAB should not be  performed to lesions likely to be malignant and operable (9). Even if FNAB does not reveal malignancy, this cannot deny  the possibility of a malignant lesion and the procedure may make an operable  lesion incurable. One should avoid invasive examinations and perform open biopsy  when CT scan indicates malignancy or the patient wants to undergo tumor  resection. However, if the diagnosis remains indeterminate and the patient's  tolerance for surgery is uncertain, FNAB may be justified (9). One should take special care, such as using a smaller bore  needle and avoiding multiple punctures with a single needle, because it is  likely that contamination by more cancer cells will provide a better opportunity  for tumor cells to grow along the needle tract.
Since the reported interval between FNAB and implantation tumor development  ranged from 6 days to 30 months (8,10), careful examination for implantation should be performed  for about 3 years.
AcknowledgmentsThe authors thank Professor J. Patrick Barron of the International Medical  Communications Center of Tokyo Medical University for reviewing the manuscript.  This work was supported in part by a Grant-in-Aid for Cancer Research from the  Japan Ministry of Health and Welfare.
References1. Sinner WN. Complication of percutaneous transthoracic needle  aspiration biopsy. Acta Radiol Diagn 1976;17:813-28.
2. Kline TS, Neal HS. Needle aspiration biopsy: a critical  appraisal: eight years and 3267 specimens later. J Am Med Assoc 1978;239:36-9.
3. Lalli AF, McCormack LJ, Zelch M, Reich NE, Belovich D.  Aspiration biopsies of chest lesions. Radiology 1978;127:35-40. MEDLINE  Abstract
4. Sinner WN, Zajicek J. Implantation metastasis after percutaneous  transthoracic needle aspiration biopsy. Acta Radiol Diagn 1976;17:473-80.
5. Sobin LH, Wittekind CH. TNM classification of Malignant Tumours,  5th edn. New York: Wiley 1997;93-100.
6. Müller NL, Bergin CJ, Miller RR, Ostrow DN. Seeding of the  malignant cells into the needle track after lung and pleural biopsy. J Can  Assoc Radiol1986;37:192-4.
7. Seyfer AE, Walsh DS, Graeber GM, Nuno IN, Eliasson AH. Chest  wall implantation of lung cancer after thin-needle aspiration biopsy. Ann  Thorac Surg1989;48:284-6. MEDLINE  Abstract
8. Harrison BDW, Thorpe RS, Kitchener PG, McCann BG, Pilling JR.  Percutaneous trucut lung biopsy in the diagnosis of localized pulmonary lesions.  Thorax1984;39:493-499. MEDLINE  Abstract
9. Wolinsky H, Lischner MW. Needle track implantation of tumor  after percutaneous lung biopsy. Ann Intern Med 1969;71:359-62. MEDLINE  Abstract
10. Berger RL, Dargan EL, Huang BL. Dissemination of cancer cells  by needle biopsy of the lung. J Thorac Cardiovasc Surg 1972;63:430-2. MEDLINE  Abstract    

Eur J Cardiothorac Surg. 2001 Oct;20(4):868-70.
Implantation metastasis caused by fine needle aspiration biopsy following curative resection of stage IB non-small cell lung cancer.

Kara M, Alver G, Sak SD, Kavukcu S.

Department of Thoracic Surgery, University of Kirikkale, School of Medicine, 71100, Kirikkale, Turkey. muratkara66@hotmail.com

Fine needle aspiration is a useful procedure in the diagnosis of lung cancer, however controversy still remains as to whether it should be employed particularly in patients with operable lung cancer. We report herein a case of metastatic tumor at the site of transthoracic needle biopsy following a curative resection in a patient with stage IB bronchogenic carcinoma. The patient was managed with aggressive chest wall resection and subsequent musculocutaneus flap transposition, however he died 11 months after the initial operation. The tumor implantation risk and the related complications should be considered in patients with operable bronchogenic carcinoma undergoing a tranthoracic needle aspiration biopsy.

(Chest. 2000;118:936-939.)

Fine-Needle Aspiration Cytologic Technique for Lung Cancer Has a High Potential of Malignant Cell Spread Through the Tract*
Noriyoshi Sawabata, MD, FCCP; Mitsunori Ohta, MD and Hajime Maeda, MD  
* From the Division of Surgery, Toneyama National Hospital, Toyonaka, Osaka, Japan.  





   Abstract



Background: Fine-needle aspiration cytologic technique (FNAC), a method to detect malignancy for undetermined pulmonary nodules, may have a high potential to spread malignant cells from the tumor to the pleural cavity.  

Objective: The authors assessed malignant cell spread through the needle tract following FNAC for peripheral lung carcinoma.  

Materials and methods: Lung lobes resected from 20 patients during the treatment of lung carcinoma were examined. The visceral pleura over the lung carcinoma was irrigated by heparinized saline solution to clean the surface, and then irrigated before FNAC and irrigated following FNAC to collect cells on the visceral pleura. FNAC was performed once for each tumor. Papanicolau’s method was employed for cytologic examination.  

Results: There were 15 specimens of adenocarcinoma, 4 specimens of squamous cell carcinoma, and 1 specimen of atypical carcinoid. The maximum diameter of the specimens ranged from 10 to 60 mm (median, 25 mm). Pleural indentation was observed in 15 samples. All results of FNAC were positive and matched the histologic diagnosis. Pre-FNAC specimens revealed a positive malignancy rate of 10% (2 of 20), but post-FNAC specimens had a rate of 60% (12 of 20; p = 0.002)  

Conclusion: FNAC has the potential to spread malignant cells to the pleural space. Further study is needed to determine the clinical significance of the spread of malignant cells in the pleural space.    

肺癌细针抽吸细胞学检查术引起针道肿瘤细胞扩散的高危险性

Sawabata N. Chest.-2000,118(4).-936一939.
    就细针抽吸细胞学检查术(FNAC)导致肿瘤细胞沿针道扩散的危险性进行了研究。
    方法20例肺癌手术切除的肺叶标本，男16例，女4例，年龄54一68岁。病理分期IA期15例，IIA期2例，IIB期3例。FNAC采用22号针，每个肿瘤穿刺1次。先用肝素化生理盐水清洗标本，以清除表面的细胞，并在FNAC前后以注射器吸取20 mI.肝素化生理盐水冲洗胸膜脏层，回收生理盐水标本，离心后涂片染色进行细胞学检查。阳性标准:鳞癌和非典型类癌瘤每一玻片肿瘤细胞多于4个;腺癌要求为成簇的肿瘤细胞。
    结果腺癌巧例，鳞癌4例，不典型类癌瘤1例。肿瘤最大直径为10一60(平均25)mmo脏层胸膜至肿瘤距离0一15(平均10) mm。存在胸膜皱缩15例，FNAC全部检查结果均为阳性，并且与组织学检查结果相符合。FNAC术前胸膜冲洗阳性2例(10% )，术后阳性12例(60%)。
    讨论FNAC具有导致肿瘤细胞扩散的潜在危险，有必要就肿瘤细胞扩散至胸膜腔的临床意义开展深人研究。

I期肺癌CT引导穿刺活检后肺内种植 

I期肺癌CT引导穿刺活检后肺内种植

P1.24-027 | Intrapulmonary recurrence after computed tomography-guided percutaneous needle biopsy of stage I lung cancer
Authors:  Yeo Kon Kye1, Young-Du Kim1, Hyun Woo Jeon1, Myung-Jun Kim2
1Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Gyeonggi-do/KOREA, 2The Catholic University of Korea, Seoul/KOREA
Background:
CT-guided percutaneous needle biopsy is a useful diagnostic procedure that is used for the evaluation of pulmonary nodules, and is regarded as a relatively safe procedure. Although tumor seeding along the biopsy needle tract after CT-guided percutaneous needle biopsy is an extremely rare complication with a reported incidence of 0.06% in Japan, it can lead to unnecessary procedures or fatal outcomes. Most of the reported cases of implantation metastasis after CT-guided percutaneous needle biopsy were about the tumor seeding, which occurred in the chest wall or the pleura; however, we present here a case of intrapulmonary recurrence after CT-guided percutaneous needle biopsy.

Methods:
A 70-year-old woman was admitted to our hospital for the evaluation of a growing lung mass. She had undergone a thoracoscopic lobectomy of the right upper lobe 17 months ago, after CT-guided percutaneous needle biopsy, using a 22-gauge needle, which had confirmed the lung mass as an adenocarcinoma. She was discharged uneventfully and had been followed-up without additional treatment because there was no evidence of metastasis to the lymph nodes or to the distant organs. On the follow-up, a CT scan of the chest revealed a small lung nodule (0.5 cm in the longest diameter), which was located in the superior segment of the right lower lobe. Six months later, a repeat CT scan of the chest showed that the nodule had grown up to 1.2 cm.

Results:
On admission, we performed successful CT-guided percutaneous needle biopsy of the lesion of the right lower lobe, and pathologic examination revealed an adenocarcinoma, which took the same characteristics as the previous diagnosis from the right upper lobe, which suggested a recurrence. We suspected implantation metastasis, and reviewed the previous biopsy procedures. Finally, we found that the biopsy needle had passed through the superior segment of the right lower lobe to target the right upper lobe lesion, and concluded that the new lesion might be an implantation metastasis, as a result of tumor seeding along the biopsy needle tract. She underwent segmentectomy of the superior segment of the right lower lobe, because there was no evidence of distant metastasis. She recovered well and was followed-up without additional treatment as before.

Conclusion:

经皮肺穿刺活检--增加胸膜复发

穿刺也要小心，毕竟是打开了肿瘤。外科手术中都很注意这个问题，如果是早期病人，还是要慎重。

经CT引导的经皮肺穿可能导致I期肺癌患者胸膜种植的几率增加，尤其在Ib期合并胸膜下损伤的患者中更明显。但是这小部分复发的病人并没有对该组平均无病生存时间造成显著影响。


Risk of Pleural Recurrence After Computed Tomographic-Guided Percutaneous Needle Biopsy in Stage I Lung Cancer Patients
Masayoshi Inoue, MD, PhDa,*, Osamu Honda, MD, PhDb, Noriyuki Tomiyama, MD, PhDb, Masato Minami, MD, PhDa,Noriyoshi Sawabata, MD, PhDa, Yoshihisa Kadota, MD, PhDa, Yasushi Shintani, MD, PhDa, Yuko Ohno, PhDc,Meinoshin Okumura, MD, PhDa
a Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
b Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Osaka, Japan
c Department of Mathematical Health Science, School of Health Science, Osaka University Graduate School of Medicine, Osaka, Japan

Accepted for publication December 16, 2010.

* Address correspondence to Dr Inoue, Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, L5-2-2 Yamadaoka, Suita-city, Osaka 565-0871, Japan (Email: mi@thoracic.med.osaka-u.ac.jp).

Background: A computed tomographic-guided percutaneous needle biopsy (CTGNB) is useful as an option for pathologic diagnosis of lungcancer, especially in patients with peripheral small-sized nodules. We aimed to assess the risk of pleural seeding of cancer cells,leading to postoperative relapse with dissemination caused by the procedure.

Methods: We investigated the clinical outcomes of 447 stage I lung cancer patients. Survival analysis was performed using the Kaplan-Meier method and a log-rank test. Pleural recurrence rates were also determined. Furthermore, propensity score matching analysis was used to reduce background bias from patient characteristics.

Results: The 5-year, disease-free survival rate was 89.1% in patients diagnosed with CTGNB, and 85.5% in those diagnosed using a transbronchial biopsy or open lung biopsy procedure. Local recurrence with pleural dissemination was found in 8 of 13 recurrence cases (61.5%) in the CTGNB group, which was higher as compared with the transbronchial biopsy or open lung biopsy group (p < 0.01). Subset analyses of p stage IB cases and those with subpleural lesions showed that local recurrence with dissemination wassignificantly more frequent in the CTGNB group (p = 0.02 and p < 0.01, respectively). In patients with subpleural lesions diagnosed with CTGNB, the rate of local recurrence with dissemination was 15.4%. Propensity score matching analysis confirmed the significantly increased frequency of pleural dissemination after CTGNB.

Conclusions: The CTGNB procedure might increase the risk of pleural implantation in stage I lung cancer patients, especially p stage IB cases with subpleural lesions, whereas the overall disease-free survival rate was not affected by this small population of patients with recurrence.

CT引导下经皮穿刺活检操作简便，检出率高，创伤小，病人痛苦小，是一种相对安全和准确的诊断方法，特别适用于纤支镜和痰细胞学很难进一步确诊的周围型肺癌病变。文献报道纤支镜和痰细胞学对周围型肺癌的阳性率分别为55%和50%[1]。如果没有丰富经验的病理医生分析活检标本，活检组织量取的不够充足，诊断的准确率会明显降低。单纯细针抽吸活检准确率仅有80%[2]。
对没有明确病理诊断的肺癌患者，无法通过纤支镜和痰细胞学获得病理学依据的情况下，使用CT引导下经皮穿刺活检可以提高肺癌诊断的准确性而且并发症少[3]。
对于痰细胞学检查和纤维支气管镜检查均为阴性的肺内占位性病变，以及放、化疗前需要明确组织学类型的肺内恶性肿瘤，CT引导下经皮肺穿刺活检技术不失为一种有效的定性诊断技术，它具有定位准确、灵敏度高、穿刺损伤小等特点。影响这一技术准确性的因素很多，包括病人是否配合、定位是否准确、穿刺器械的选择、取材部位的选择等，其中穿刺器械和取材部位的选择非常重要。
目前常用套管针/带芯活检针（core needle），往往能够取得更多组织，而且操作更加方便，与细针抽吸相比准确率更高（92.5%）。套管针穿刺、穿刺针取材，可以做到一次进针、反复多次取材，在取材过程中还可以调整取材方向，并且大大减少了气胸及肺内出血的发生率。取材部位的选择，一定要选取肿瘤的实性部分取材，避开远侧阻塞性炎症或肺不张区域，必要时术前可进行增强扫描明确肿瘤实质成分所在部位。
并发症发生率为在30%，主要表现为气胸，一般不严重。主要是因为病灶太小（＜3cm）,反复穿刺容易刺破胸膜导致气胸。咯血多为一过性。除了操作器械的帮助外，还要准确掌握适应证和禁忌证。病灶至少应大于1cm，有严重肺气肿、肺纤维化、肺大泡、严重心功能不全、无法控制咳嗽者并发症发生率高。
参考文献
   毛进星 张宗城 李凯滨  CT引导下经皮穿刺活检术在肺癌诊断中的应用
许茜 李如迅  彰俊杰   CT引导下经皮肺穿刺活检在肺肿瘤诊断中的应用
1       查人俊等主编. 现代肺癌诊断与治疗, 人民军医出版社 1993；5~6
2       Austin JHM, Cohen MB.Value of having a cytopathologist present during percutaneous fine-needleaspiration biopsy of lung：report of 55 cancer patients and meta-analysis ofthe literature[j].AJR,1993,160(1)：175-177.
3       陈云涛, 朱丹, 徐以. 弹簧芯状活检针在CT引导经皮肺穿刺活检中的应用. 放射学实践, 2001, 16（4）: 246~247。