Intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration

OBJECTIVE: The aim of this study was to assess the adequacy of our intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration. METHODS: Patients who had stage IA non-small cell lung cancer (NSCLC) with a maximum tumor diameter of 2 cm or less were candidates for limited resection. If bronchioloalveolar carcinoma (BAC) was suspected on computed tomography and intraoperative pathologic exploration revealed the lesion as BAC without foci of active fibroblastic proliferation (Noguchi type A and B), wedge resection was performed. If the tumor was not suspected of being Noguchi type A or B, extended segmentectomy with intraoperative lymph node exploration was performed. RESULTS: Limited resection was performed in 34 patients, wedge resection in 14, and extended segmentectomy in 20. The median follow-up period after wedge resection was 36 months, and all patients are alive with no signs of recurrence. The median follow-up period after extended segmentectomy was 54 months. No local recurrences were found, but distant metastasis was diagnosed in one patient. The 5-year survival rate after extended segmentectomy was 93%. In the same period, lobectomy was performed in 57 patients with stage IA NSCLC with a maximum tumor diameter of 2 cm or less, and the 5-year survival rate was 84%. There were no significant differences in 5-year survival between extended segmentectomy and lobectomy. CONCLUSIONS: Careful selection of patients based on high-resolution computed tomography findings and intraoperative pathologic exploration makes intentional limited resection an acceptable option for the treatment of small peripheral NSCLC.     

Intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration

Objective: The aim of this study was to assess the adequacy of our intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration. Methods: Patients who had stage IA non-small cell lung cancer (NSCLC) with a maximum tumor diameter of 2 cm or less were candidates for limited resection. If bronchioloalveolar carcinoma (BAC) was suspected on computed tomography and intraoperative pathologic exploration revealed the lesion as BAC without foci of active fibroblastic proliferation (Noguchi type A and B), wedge resection was performed. If the tumor was not suspected of being Noguchi type A or B, extended segmentectomy with intraoperative lymph node exploration was performed. Results: Limited resection was performed in 34 patients, wedge resection in 14, and extended segmentectomy in 20. The median follow-up period after wedge resection was 36 months, and all patients are alive with no signs of recurrence. The median follow-up period after extended segmentectomy was 54 months. No local recurrences were found, but distant metastasis was diagnosed in one patient. The 5-year survival rate after extended segmentectomy was 93%. In the same period, lobectomy was performed in 57 patients with stage IA NSCLC with a maximum tumor diameter of 2 cm or less, and the 5-year survival rate was 84%. There were no significant differences in 5-year survival between extended segmentectomy and lobectomy. Conclusions: Careful selection of patients based on high-resolution computed tomography findings and intraoperative pathologic exploration makes intentional limited resection an acceptable option for the treatment of small peripheral NSCLC. Read at the Fifty-sixth Annual Meeting of the Japanese Association for Thoracic Surgery, Panel Discussion, Tokyo, November 19–21, 2003.     

Early results of a prospective study of limited resection for bronchioloalveolar adenocarcinoma of the lung

BACKGROUND: We reported that bronchioloalveolar adenocarcinoma (BAC) without active fibroblastic proliferation of the lung had no lymph node and pulmonary metastasis and had a favorable prognosis. However, there has been no prospective trial regarding limited pulmonary resection for this type of BAC. The purpose of this study is to confirm the effectiveness of limited resection for histologically confirmed BAC without active fibroblastic proliferation. METHODS: From 1996 through 1999, 42 patients who had small peripheral lung tumors (< or = 20 mm), suspected of being BAC, were enrolled in this trial. The patient population consisted of 24 men and 18 women with a mean age of 58.4 years. Limited resection was completed when BAC, without both active fibroblastic proliferation and lymph node metastasis, was confirmed histologically by intraoperative pathologic examination. RESULTS: Limited resection was completed in 36 patients, wedge resection in 34, and segmentectomy in 2 patients. In 6 patients, the procedure was converted into lobectomy because of pathologic invasive sign in 3, active fibroblastic proliferation in 1, and for other reasons in 2 patients. All patients have been followed for a median follow-up period of 30 months and are alive without sign of recurrence. CONCLUSIONS: Our early results indicate that limited resection may be an acceptable alternative to lobectomy for histologically confirmed BAC without active fibroblastic proliferation.     

Extended segmentectomy for small-sized peripheral CN0 non-small cell lung cancer

With advances in diagnostic imaging techniques, small-sized lung cancers are now diagnosed much more often. Lobectomy has been the standard surgical procedure even for small lung for decades. Is it necessary to remove uniformly such a large amount of lung tissue for all tiny cancers? Extended segmentectomy as an intentional lesser resection for a peripheral clinical N0 lung cancer tumor 2 cm or less in diameter in patients able to tolerate a lobectomy, in which the resection line of the lung is placed beyond the burdened segment if required for sufficient margins, requires confirmation of surgical N0 disease by intraoperative examination of lymph node frozen sections. The procedure should be converted to standard lobectomy if the sections are positive. Recently, several reports have suggested that the prognosis after lesser resection in such highly selected patients is no worse than that following standard lobectomy. In addition to preservation of pulmonary function, this lung-saving surgery provides a second chance to patients who have a higher risk of metachronous disease after surviving the first disease. Extended segmentectomy might be an alternative standard surgery for patients with small peripheral lung cancers. However, patient selection with intraoperative pathologic examination and accurate technique with wide lesion margins must be strictly adhered to.     

Analysis of lobectomy for small peripheral lung cancer supports extended segmentectomy

We reviewed the records of 53 patients who underwent lobectomy for peripheral non-small cell lung cancer under 2 cm in diameter and established a rationale for segmentectomy with intraoperative lymph nodes dissection (extended segmentectomy). Five patients (9.4%) had intrapulmonary metastases. Nodal status was NO in 34 patients (64.2%), N1 in 7 (13.2%), and N2 in 12 (22.6%). Based on examination of intraoperative frozen sections, 31 patients lacking lymph node metastases and visceral pleural involvement could have been candidates for extended segmentectomy. Twenty-seven had stage I disease on postoperative examination of paraffin-embedded sections. Of the remaining 4 patients, 1 had involvement of intrapulmonary lymph nodes in the segment where the primary lesion originated. Another patient had involvement only at the first mediastinal lymph node level, representing a “skipping metastasis”. The remaining 2 patients had no lymph node involvement, but had intrapulmonary metastases in the same segments as the primary lesion. We conclude that an extended segmentectomy may be as effective as lobectomy for treatment of peripheral non-small cell lung cancer under 2 cm in diameter without evident lymph node involvement.     

Clinical study of limited operation of lung cancer with reference to the operative procedure

From 1977 to 1987, 27 cases of primary lung cancer were resected by the limited operation, 7 segmentectomy and 20 wedge resection. All cases of segmentectomy were considered to be potentially curative and 2 cases of them were X-ray negative early squamous cell carcinoma originated from the subsegmental bronchus. The mean tumor size of the other 5 peripheral cases performed segmentectomy was 37.6 mm in diameter. Two cases of segmentectomy died from cancer recurrence, but 2 cases are still alive more than 4.5 years after operation. All cases of wedge resection were originated peripherally, and 6 cases were thought to be potentially curative and the mean tumor size was 22.4 mm in diameter. Three cases of them died, 1 from the tumor metastasis and 2 from the other diseases than lung cancer, but the other cases undergone potentially curative wedge resection are alive without recurrence 1-3.6 years after operation. The limited operation should be indicated for the peripheral lung cancer without lymph node metastasis in the patients with marked cardiac and/or pulmonary impairment. The small nodule located in subpleural lung can be resected easily by the wedge resection, but the segmentectomy should be recommended for the tumor which is larger in size or located more deeply under the visceral pleura. Especially X-ray negative early squamous cell carcinoma of the bronchus can be curatively resected by the segmentectomy with lymph node dissection, if the tumor exists in the level of subsegmental bronchus or more peripherally. Palliative minimal resection for the advanced lung cancer seemed to be not effective of their long-surviving.     

Review and evaluation of limited resection for early lung cancer

Limited resection for early lung cancer has been associated with significantly higher local recurrence rates based on previous reports such as those from lung cancer study groups. On the other hand, a few groups demonstrated that patients with small peripheral cancer who undergo limited resection have comparable survival rates with those who undergo lobectomy. Recent advances in radiologic investigation and pathologic analysis have broadened the indications for limited resection. Since the introduction of the adenocarcinoma classification by Noguchi surgery for localized bronchioloalveolar carcinoma has focused on limited resection. Caution is necessary when performing wedge resection even if 10 mm or less in diameter and in compromised segmentectomy for early lung cancer. Although limited resection is still controversial intentional segmentectomy for localized bronchioloalveolar carcinoma or less than 20 mm or less in diameter may be recommended without evidence-based medicine. It is important to accumulate further evidence clarifying the survival and function benefits of limited resection. New therapeutic modalities for limited surgery for small-sized lung cancer may increase patient life expectancy.     

Video-assisted thoracoscopic surgery (VATS) segmentectomy for small peripheral lung cancer tumors: intermediate results

Background We investigated the feasibility and suitability of video-assisted thoracoscopic surgery (VATS) segmentectomy for curing selected non-small cell lung cancer (NSCLC) with this less invasive technique Methods We performed VATS segmentectomy for small (<20 nm) peripherally located tumors and pathologically confirmed lobar lymph node-negative disease by frozen-section examination during surgery. Of the 34 patients who underwent this limited resection, 22 were treated with complete hilar and mediastinal lymph node dissection (intentional group), whereas 12 patients who were deemed to be high risk in their toleration for lobectomy underwent VATS segmentectomy with incomplete hilar and mediastinal lymph node dissection (compromised group). The surgical and clinical parameters were evaluated and compared with those of segmentectomy under standard thoracotomy to evaluate the technical feasibility of VATS segmentectomy. Results We found that VATS segmentectomy could be performed safely with a nil mortality rate and acceptably low morbidity. The mean period of observation was relatively short at 656.7±572.1 and 783.4±535.8 days in the intentional and compromised groups, respectively. At the time of writing, all intentional patients remain alive and free of recurrence. There were two cases of non-cancer-related death in the compromised group. Clinical data indicated that VATS segmentectomy caused the same number or fewer surgical insults compared with segmen-tectomy under standard thoractomy Conclusions The present results are intermediate only; the rate of long-term survival and the advantages of the less invasive procedure still need further investigation. Nevertheless, we believe that VATS segmentectomy with complete lymph node dissection is a reasonable treatment option for selected patients with small peripheral NSCLC.     

Successful lingular segmentectomy using bronchoplasty in a patient with early hilar second primary lung carcinoma

A 71-year-old man was admitted to our hospital with a small protrusive lesion at the lingular orifice of the left upper bronchus. He had undergone a right lower lobectomy and mediastinal dissection for lung carcinoma (large cell carcinoma, pT1N0M0) 14 months earlier. Early hilar squamous cell carcinoma was diagnosed by chest radiograph, CT and transbronchial biopsy. We performed a lingular segmentectomy with wedge resection of the left upper bronchus and N 1 lymph node dissection. The tumor was histopathologically diagnosed as early hilar second primary lung carcinoma. The patient's postoperative course was uncomplicated. At present, he is alive with good respiratory condition and without any evidence of recurrence. Segmentectomy is appropriate for a patient with contralateral second primary lung carcinoma as well as a patient with early hilar lung carcinoma. Bronchoplasty seems to increase the likelihood that such a patient will be a candidate for segmentectomy.     

胸腔镜辅助小切口手术诊治肺周围型结节

目的探讨胸腔镜辅助小切口手术在诊断和治疗肺周围型结节病变中的临床应用价值。方法胸腔镜辅助小切口手术诊治肺周围型结节55例，其中单发结节54例，多发结节1例。肺楔形切除术23例；肺叶切除联合淋巴结清扫治疗原发性肺癌32例，采用常规开胸手术器械及胸腔镜用器械切除肺叶，自制淋巴结摘除钳完成淋巴结清扫。结果55例均在胸腔镜下完成手术。手术时间35～180min，平均109min，术中出血量50～400ml，平均122min。均未输血，1例术后漏气术后32d出院，1例切口延迟愈合，术后19d出院，余53例术后住院4～11d，平均8．3d。无严重并发症。术后病理：良性病变15例，原发性肺癌38例，非典型性腺瘤样增生1例，转移性肺癌1例。良性病变行肺楔形切除术，32例原发性肺癌行解剖学肺叶切除联合淋巴结清扫，4例肺癌胸膜广泛播散未手术处理，2例肺癌因肺功能差行姑息性肺楔形切除。结论胸腔镜辅助小切口手术有助于明确诊断肺周围型结节病变，治疗临床早期原发性肺癌的长期疗效有待随访观察。     

Surgical treatment of non-small cell lung cancer 1 cm or less in diameter

BACKGROUND: Routine lung cancer screening does not currently exist in the United States. Computed tomography can detect small cancers and may well be the screening choice in the future. Controversy exists, however, regarding the surgical management of these small lung cancers. METHODS: The records of all patients were reviewed who underwent resection of solitary non-small cell lung cancers 1 cm or less in diameter from 1980 through 1999. RESULTS: The study included 100 patients (56 men and 44 women) with a median age of 67 years (range 43 to 84 years). Lobectomy was performed in 71 patients, bilobectomy in 4, segmentectomy in 12, and wedge excision in 13. Ninety-four patients had complete mediastinal lymph node dissection. The cancer was an adenocarcinoma in 48 patients, squamous cell carcinoma in 26, bronchioloalveolar carcinoma in 19, large cell carcinoma in 4, adenosquamous cell carcinoma in 2, and undifferentiated in 1. Tumor diameter ranged from 3 to 10 mm. Seven patients had lymph node metastases (N1, 5 patients; N2, 2 patients). Postsurgical stage was IA in 92 patients, IB in 1, IIA in 5, and IIIA in 2. There were four operative deaths. Follow-up was complete in all patients and ranged from 4 to 214 months (median 43 months). Eighteen patients (18.0%) developed recurrent lung cancer. Overall and lung cancer-specific 5-year survivals were 64.1% and 85.4%, respectively. Patients who underwent lobectomy had significantly better survival and fewer recurrences than patients who had wedge excision or segmentectomy (p = 0.04). CONCLUSIONS: Because recurrent cancer and lymph node metastasis can occur in patients with non-small cell lung cancers 1 cm or less in size, lobectomy with lymph node dissection is warranted when medically possible.     

Surgical procedure of thoracoscopic and video-assisted anatomical segmentectomy for small peripheral lung cancer

Recently, small peripheral lung cancers which is indicated limited resection are frequently found by HRCT or PET. The limited resection for lung cancer includes thoracic and video-assisted anatomical segmentectomy (VATS segmentectomy) and wedge resection of the lung parenchyma. In anatomical segmentectomy, intra-plumonary lymph nodes are dissected, on the other hand, those lymph nodes can not be dissected in wedge resection. Consequently, segmentectomy will be radical procedure for lung cancer compared with wedge resection. Thoracic surgeons are required to perform anatomical segmentectomy for small peripheral lung cancer. The anatomical segmentectomy is not familiar procedure for recent thoracic surgeons. Thoracic surgeons should be skilled in that procedures. This is a review of basic procedures of VATS segmentectomy for lung cancer for young thoracic surgeones.     

Results of surgical treatment for small (2 cm or Under) adenocarcinomas of the lung

Purpose The objectives of this study were to identify the clinicopathologic characteristics and prognostic factors of small (2 cm or less in diameter) adenocarcinomas, and furthermore to assess the acceptability of performing a limited pulmonary resection in such patients. Methods We retrospectively reviewed 523 cases of cT1N0M0 peripheral adenocarcinoma measuring 2 cm or less on diagnostic images treated by a complete resection between 1991 and 2004. Results The overall 5-year survival rate of the patients with small adenocarcinomas was 83.6%. Univariate and multivariate analyses identified an older age, male sex, wedge resection, advanced stage, and Noguchi classification of C, D, E, or F as independent prognostic factors that adversely affected overall survival. However, there were no significant differences in the survival according to surgical procedure in the patients whose tumors had a maximum diameter of 1.0 cm or less or in Noguchi type A and B cases. Conclusions Age, sex, surgical procedure, p-stage, and Noguchi classification were independent prognostic factors for survival in patients with small adenocarcinomas. A segmentectomy is therefore considered to be an acceptable alternative to a lobectomy for adenocarcinomas of 2 cm or less in diameter. A wedge resection may be acceptable for tumors measuring 1 cm or less in diameter or Noguchi type A and B tumors.     

Prospective study of extended segmentectomy for small lung tumors: the final report

BACKGROUND: Minimal resection of small lung tumors is still controversial. This study was conducted to clarify whether this type of operation is acceptable. METHODS: From January 1992 to December 1994, 73 patients were registered in a multiinstitutional trial of limited resection for peripheral lung tumors less than 2 cm in diameter. The operative procedure consisted of extended segmentectomy in which the cut line of the lung was beyond the burdened segment, confirming N0 disease by intraoperative lymph node examination of frozen sections. The operation was changed to other procedures if the report was positive. RESULTS: All the patients were observed more than 5 years. There were no perioperative deaths and no major complications. A total of 55 patients were finally enrolled in this study. Ten patients died postoperatively, 4 of lung cancer and the remaining 6 died of other diseases, with no signs of recurrence. The 5-year survival rate, excluding these 6 patients, was 91.8%; for all patients including those who died it was 81.8%. A total of 18 patients were not included in this study for various reasons. The decrease in forced vital capacity was 11.3% +/- 9.8% compared with the preoperative value. CONCLUSIONS: Extended segmentectomy is an alternative method as a standard operation for patients with small peripheral lung tumors, and the loss of lung function is minimal. However, patient selection must be strict, with intraoperative pathologic examination, and a wide margin to the lesion beyond the burdened segment is mandatory.     

Surgical treatment and outcome for postoperative recurrent or second primary lung cancer

From 2000 to 2009, we retrospectively reviewed 62 patients who underwent surgical treatment for postoperative recurrent or 2nd primary lung cancer. Of the 62 patients, 43 were men and 19 were women with an average age of 67.6 years old. The histology of the initial primary lung cancer was adenocarcinoma in 42 patients, squamous cell carcinoma in 18, large cell carcinoma in 1 and small cell carcinoma in 1. The surgical procedures for 1st operation were lobectomy with mediastinal lymph node dissection in 52, bilobectomy with mediastinal lymph node dissection in 4, sleeve lobectomy with mediastinal lymph node dissection in 3, and lobectomy + segmentectomy or wedge resection with mediastinal lymph node dissection in 3. p-stage of the 1st primary lung cancer was IA in 22, IB in 16, II A in 7, IIB in 6, IIIA in 6, IIIB in 4, and IV in 1. On the 2nd operation, 56 patients underwent limited surgery. Five patients underwent a lobectomy twice metachronous bilateral lesions and 1 patient underwent completion pneumonectomy (CP) at the 2nd operation. The average age at 2nd operation was 71.8 years old. Of these, 42 patients were diagnosed 2nd primary lung cancer, 20 patients were recurrent disease histologically. The 5-year survival rate of the patients with metachronous and recurrent disease from the 2nd operation was 54.1%, and 43.1%, respectively. Although lobectomy or CP should be considered the surgical procedure of choice for patients with metachronous lung cancer, with this result, we consider that postoperative good survival can be expected by even the limited operation for cases of postoperative recurrent or 2nd primary lung cancer because of possible early detection. We conclude that limited surgery may be a treatment of choice for recurrent or 2nd primary lung cancer after initial operation.     

Limited resection trial for pulmonary ground-glass opacity nodules: fifty-case experience

OBJECTIVE: This study was undertaken to determine the recurrence rate after limited resection of small lung carcinoma and to evaluate intraoperative frozen-section examination accuracy for Noguchi classification. METHODS: Enrollment requirements were as follows: pulmonary nodule 2 cm or smaller, diagnosed or suspected clinical T1 N0 M0 carcinoma in the lung periphery, and ground-glass opacity findings and lack of evident pleural indentations or vascular convergence on high-resolution computed tomographic scan. A wedge or segmental resection specimen, removed with custom stapler cartridges, was immediately reinflated and examined by frozen-section with hematoxylin-eosin and Victoria blue-van Gieson stains. If the tumor was confirmed as Noguchi type A or B with resection margins greater than 1 cm, the patient was closed and followed up on an outpatient basis. End points were 5-year disease-free survival and intraoperative classification accuracy. RESULTS: From August 1998 through October 2002, a total of 50 patients were enrolled (20 men and 30 women, ages 30-77 years). Tumor sizes ranged from 2 to 21 mm (11 mm average). There were 2 Noguchi type A tumors, 23 Noguchi type B tumors, 15 Noguchi type C tumors, 5 atypical adenomatous hyperplasias, 4 fibroses, and 1 granuloma. Frozen-section accuracy was approximately 98% (39/40). One intraoperative type B diagnosis was revised to type C after postoperative pathologic study. No morbidity, mortality, or recurrence has been seen with a median follow-up of 50 months. CONCLUSION: Noguchi type A and B tumors may well be in situ carcinomas, and frozen-section examination was highly accurate. Neither local recurrence nor distant metastases have been found to date. Limited resection initial results appear promising.     

Hepatic resection for metastatic disease

Hepatic resection for metastatic disease is reviewed in 30 patients (mean age 58.9 years). The primary site was the colorectum in 25; the other primary tumours were leiomyosarcoma, plasmacytoma, and adenocarcinoma (all of gastric origin), ocular melanoma and an unknown primary. Operative procedures included 7 wedge resections, 5 segmentectomies and 21 lobectomies (11 right, 4 extended right and 6 left). Major complications in seven patients included intraoperative hemorrhage in three, two of whom died, bile-duct injury in two, small-bowel infarction in one and cerebrovascular accident in one. Operative death rate was 6.7% (2 of 30). Thirteen patients were alive and free of disease a mean of 24 months after hepatic resection while 5 more were alive with disease at a mean of 36.9 months. Life-table analysis projected a 5-year survival of 50.3% for those with colorectal primaries, with no apparent difference in survival between patients with single (55.0%) and multiple (54.0%) metastases. Improved survival was projected for patients with metachronous (66.6%) versus synchronous (45.0%) tumours, primary Dukes' class A or B (66.1%) versus Dukes' class C (46.0%) tumours and those having wedge resection or segmentectomy (66.6%) versus lobectomy or extended lobectomy (48.0%). Hepatic resection for metastatic disease can be done with acceptable morbidity and mortality and the expectation of substantially prolonged survival particularly in patients with metachronous lesions or Dukes's A or B colorectal primary lesions.     

Analyses of segmental lymph node metastases and intrapulmonary metastases of small lung cancer

BACKGROUND: Curativity and indications for limited resection of small peripheral lung cancer remain controversial. METHODS: Pathologic investigations of segmental lymph node metastases and intrapulmonary metastases in the resected lobe were performed for 94 small peripheral lung cancers (3.0 cm or less in diameter). RESULTS: Nine patients had segmental lymph node metastases, 1 had intrapulmonary metastases, and 1 had both. Of these 11 patients, 5 had metastases limited to the primary tumor-bearing segments, 2 had metastases in nonprimary tumor-bearing segments, and 4 had metastases in both. Of the 10 patients with segmental lymph node metastases, 7 had metastases in both lobar-hilar and mediastinal lymph nodes, and 3 of 8 with adenocarcinoma had a tumor 2.0 cm or less. CONCLUSIONS: Segmentectomy seems more favorable than wedge resection, but the risk of remnant tumor remains as compared with lobectomy. Evaluation of lobar-hilar or mediastinal lymph nodes is helpful to determine the presence or absence of segmental lymph node metastases. Limited resection can be undertaken with smaller tumors to allow preservation of more lung function while accepting a somewhat enhanced risk of recurrence.     

Clinical characteristics after surgery of non-small cell lung cancer which measures 20 mm or less in diameter

Today's advances in diagnostic image-technologies often enable us to find small lung cancers. However, we have few definite strategies including how to diagnosis and treat them. In this study, we performed a retrospective analysis of 122 consecutive patients who underwent surgery for non-small cell lung cancer 20 mm or less in diameter to clarify the clinical features of small lung cancer. Of 122 patients, there were 114 patients of pN0, and 8 patients with lymph node metastasis. Seventy three patients underwent lobectomy, 45 underwent segmentectomy, and 4 underwent wedge resection based on the findings of preoperative CT and anatomical and oncological view during operation. Overall survival rate( OS) and progression free survival( PFS) at 3-year was, 94% and 84%, respectively. There were no differences in OS or PFS between lobectomy group and limited resection group, which might suggest that we adapted appropriate surgical procedures. Multivariate analysis revealed that pathological pleural invasion, lymphatic vessel invasion, and vascular vessel invasion were likely to be unfavorable prognostic-factors. We believe that further investigations should be required to clarify the characteristics of small lung cancer.     

Clinicopathological study of early peripheral adenocarcinoma of the lung

Fifty surgically resected small peripheral adenocarcinomas measuring 20 mm or less in greatest diameter were reviewed according to Noguchi classification (1995). Type A (localized bronchioloalveolar carcinoma: LBAC) and type B (LBAC with foci of structural collapse of alveoli) showed no lymph node metastasis and in these two types, 5-year survival was 100%. Histologic types A and B in Noguchi classification are thought to be early peripheral adenocarcinoma. By further evaluation of preoperative imaging diagnosis, operative procedure and pathological study patients with early peripheral adenocarcinoma would be able to become candidates for limited surgery (segmentectomy or partial resection).