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

Limited resection and two-staged lobectomy for non-small cell lung cancer with ground-glass opacity

Background

Lung tumors showing ground-glass opacities on high-resolution computed tomography indicate the presence of inflammation, atypical adenomatous hyperplasia, or localized bronchioloalveolar carcinoma. We adopted a two-staged video-assisted thoracoscopic lobectomy strategy involving completion lobectomy for localized bronchioloalveolar carcinoma with an invasive component according to postoperative pathological examination by permanent section after partial resection.

Methods

Forty-one patients with undiagnosed small peripheral ground-glass opacity lesions underwent partial resection from 2001 to 2007 in Hokkaido University Hospital. Localized bronchioloalveolar carcinoma was classified according to the Noguchi classification for adenocarcinoma. Malignant lesions other than Noguchi types A and B were considered for completion lobectomy and systemic mediastinal lymphadenectomy. Perioperative data of completion video-assisted thoracoscopic lobectomies were compared with data of 67 upfront video-assisted thoracoscopic lobectomies for clinical stage IA adenocarcinoma performed during the same period.

Results

Postoperative pathological examination revealed 35 malignant and 6 non-malignant diseases. Histologically, all of the malignant diseases were adenocarcinomas of Noguchi type A (n = 7), B (n = 9), C (n = 18), and F (n = 1). Eleven of 19 patients (58%) with Noguchi type C or F underwent two-staged video-assisted thoracoscopic lobectomy. Three patients refused a second surgery. There was no cancer recurrence. The two-staged lobectomy group had a significantly longer operative time and more blood loss than the upfront lobectomy group. There was no surgical mortality or cancer recurrence.

Conclusions

Two-staged lobectomy for undiagnosed small peripheral ground-glass opacity lesions showed satisfactory oncological results. However, low compliance for and invasiveness of the second surgery are concerns associated with this strategy.

Port-access thoracoscopic anatomical lung subsegmentectomy

OBJECTIVES

The diagnosis of small lung nodules has increased in recent years; limited resection and minimally invasive surgery are highly desirable in patients with these lesions. While wedge resection may be curative for small lung nodules, the technique is sometimes difficult to perform when the tumour nodule is near the pulmonary hilum. In such situations, either anatomical segmentectomy or subsegmentectomy can obtain an adequate surgical margin; port-access thoracoscopic surgery is the preferred type of minimally invasive surgery. Three-dimensional (3D) computed tomography (CT) simulations are reportedly useful in planning and performing thoracoscopic surgery. We use 3D CT simulation to aid thoracoscopic segmentectomy for small lung nodules and subsegmentectomy for even smaller nodules and conduct here a retrospective evaluation of the clinical results of subsegmentectomy. We present our technique for 3D CT simulation-assisted port-access thoracoscopic subsegmentectomy in the superior segment of the left lower lobe.

METHODS

Between July 2008 and June 2012, 15 patients underwent port-access thoracoscopic subsegmentectomy. We evaluated the pathological diagnoses, the tumour sizes, the indications, the operative times and the volumes of blood loss.

RESULTS

Seven patients were diagnosed with lung cancer (LC) and eight had metastatic lung tumours (MLT). The median tumour size was 12 mm. The indication for using this surgical technique was to secure surgical margins in 13 patients (LC, 6; MLT, 7) and because of poor surgical risk in two patients (LC, 1; MLT, 1). The mean surgical time was 166 min and the median blood loss was 19 ml. There were no recurrences.

CONCLUSIONS

Port-access thoracoscopic lung subsegmentectomy using 3D CT simulation can be safely performed and is able to secure adequate surgical margins.

Lung cancer with scattered consolidation: detection of new independent radiological category of peripheral lung cancer on thin-section computed tomography

OBJECTIVES

Ground glass opacity (GGO) on thin-section computed tomography (CT) has been reported to be a favourable prognostic marker in lung cancer, and the size or area of GGO is commonly used for preoperative evaluation. However, it can sometimes be difficult to evaluate the status of GGO.

METHODS

A retrospective study was conducted on 572 consecutive patients with resected lung cancer of clinical stage IA between 2004 and 2011. All patients underwent preoperative CT and their radiological findings were reviewed. The areas of consolidation and GGO were evaluated for all lung cancers. Lung cancers were divided into three categories on the basis of the status of GGO: GGO, part solid and pure solid. Lung cancers in which it was difficult to measure GGO were selected and their clinicopathological features were investigated.

RESULTS

Seventy-one (12.4%) patients had lung cancer in whom it was difficult to measure GGO. In all these cases, consolidation and GGO were not easily measured because of their scattered distribution. In this cohort, nodal metastases were not observed at all. The frequency of other pathological factors, such as lymphatic and/or vascular invasion, was significantly lower (P < 0.0001).

CONCLUSIONS

This new category of lung cancer with scattered consolidation on thin-section CT scan tended to be pathologically less invasive. When lung cancer has GGO and is difficult to measure because of a scattered distribution, its prognosis could be favourable regardless of the area of GGO. This new category could be useful for the preoperative evaluation of lung cancer.

Impact of GLUT1 and Ki-67 expression on early‑stage lung adenocarcinoma diagnosed according to a new international multidisciplinary classification

High expression levels of glucose transporter isoform 1 (GLUT1) and Ki-67 are reportedly associated with malignancy-related clinicopathological factors in malignant tumors. Recently, a new histological IASLC/ATS/ERS classification for lung adenocarcinoma was proposed. In this study, we investigated the clinicopathological impact of GLUT1 and Ki-67 expression on early-stage lung adenocarcinoma classified according to the IASLC/ATS/ERS classification. One hundred and five patients with completely resected stage IA lung adenocarcinoma were retrospectively classified into two groups, a 'non-invasive type' (n=31) or an 'invasive type' (n=74), based on the IASLC/ATS/ERS classification. GLUT1 and Ki-67 expression status was evaluated using immunohistochemistry. The epidermal growth factor receptor (EGFR) and KRAS mutation status was determined using PCR-based assays. Positive GLUT1 and Ki-67 expression and EGFR and KRAS mutations were detected in 28 (27%), 33 (31%), 51 (49%) and 5 (8%) cases, respectively. Positive GLUT1 expression was significantly associated with a wild-type EGFR and mutant KRAS status. A multivariate analysis revealed that positive GLUT1 expression was independently associated with the 'invasive type'. In multivariate analyses for overall survival (OS) and disease-free survival (DFS), positive Ki-67 and GLUT1 expression was the only independent factor for a poor OS (P=0.012) and DFS (P=0.040), respectively. In addition, when stratified according to the GLUT1 and Ki-67 status, double-positive cases had the poorest DFS and OS times, compared with the other categories. Positive GLUT1 expression is associated with the invasive character of early-stage lung adenocarcinoma and with early disease relapse. Our results strongly suggest that GLUT1 and Ki-67 play important roles in acquiring biological malignant potential in early-stage lung adenocarcinoma.

Recommendations for the management of subsolid pulmonary nodules detected at CT: a statement from the Fleischner Society

This report is to complement the original Fleischner Society recommendations for incidentally detected solid nodules by proposing a set of recommendations specifically aimed at subsolid nodules. The development of a standardized approach to the interpretation and management of subsolid nodules remains critically important given that peripheral adenocarcinomas represent the most common type of lung cancer, with evidence of increasing frequency. Following an initial consideration of appropriate terminology to describe subsolid nodules and a brief review of the new classification system for peripheral lung adenocarcinomas sponsored by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS), six specific recommendations were made, three with regard to solitary subsolid nodules and three with regard to multiple subsolid nodules. Each recommendation is followed first by the rationales underlying the recommendation and then by specific pertinent remarks. Finally, issues for which future research is needed are discussed. The recommendations are the result of careful review of the literature now available regarding subsolid nodules. Given the complexity of these lesions, the current recommendations are more varied than the original Fleischner Society guidelines for solid nodules. It cannot be overemphasized that these guidelines must be interpreted in light of an individual's clinical history. Given the frequency with which subsolid nodules are encountered in daily clinical practice, and notwithstanding continuing controversy on many of these issues, it is anticipated that further refinements and modifications to these recommendations will be forthcoming as information continues to emerge from ongoing research.

Percutaneous computed tomography-guided coaxial core biopsy for small pulmonary lesions with ground-glass attenuation

INTRODUCTION

The aim of this study was to investigate the diagnostic value of percutaneous computed tomography (CT)-guided coaxial transthoracic needle biopsy (TNB) for small pulmonary lesions (≤ 3 cm) with persistent ground-glass opacity (GGO).

METHODS

From January 2004 to February 2010, consecutive patients with persistent small GGO lesions (≤ 3 cm) who underwent CT-guided TNB were analyzed. The pathologic results of CT-guided TNB were compared with final diagnoses, and the GGO percentage on CT was correlated with the stromal invasion in surgical pathology.

RESULTS

We performed CT-guided TNB on 1612 patients during the study period. Among them, 55 patients had persistent small GGO lesions (size range 0.5-3.0 cm; 1.72 ± 0.73 cm), 47 were diagnosed with lung adenocarcinomas, and 8 with benign nonspecific lesions. Minor procedure-related complications occurred in 26 patients (47.3%) with small pneumothorax and 11 patients (20.0%) with self-limited mild hemoptysis. The final diagnoses of the 43 patients receiving lobectomy were invasive adenocarcinoma (n = 23), pure bronchioloalveolar carcinoma (n = 19), and mucosa-associated lymphoid tissue lymphoma (n = 1). The diagnostic accuracy was 93.0% (40/43) using CT-guided TNB. Pure GGO lesions had a higher incidence of pure bronchioloalveolar carcinoma than GGO-dominant lesions (70.0% versus 21.7%; p = 0.004). Compared with surgical pathology, stromal invasion was underestimated in 43.5% (10/23) of the TNB specimens, especially in pure GGO lesions (83%, 5/6). In logistic regression analysis, the GGO percentage correlated inversely with stromal tumor invasion (p = 0.0028).

CONCLUSIONS

CT-guided coaxial TNB is a safe and useful method for diagnosing small (≤ 3 cm) persistent GGO lesions. Stromal invasion may be underestimated by TNB in GGO lesions.

Anatomic segmentectomy for the solitary pulmonary nodule and early-stage lung cancer

BACKGROUND

Anatomic segmentectomy is a versatile sublobar resection approach that can be both diagnostic and therapeutic in the setting of the indeterminate pulmonary nodule (IPN), metastasectomy, as well as small, peripheral cancers. We analyzed the clinical indications and perioperative outcomes after anatomic segmentectomy and explored its utility in the diagnosis and treatment of IPNs and small stage IA lung cancers.

METHODS

This study is a retrospective review of 785 consecutive patients undergoing anatomic segmentectomy from 2002 to 2010. Primary outcome variables include perioperative course, morbidity, mortality, recurrence patterns, and survival.

RESULTS

Surgical indications included IPN (62.4%), known lung cancer (27.6%), suspected metastasis (4.1%), bullous disease (3.7%), or other (2.2%). Video-assisted thoracic surgery was employed in 468 (59.6%) and open thoracotomy in 317 (40.4%) patients. Median length of stay was 6 days. Overall complication rate was 34.9%. Thirty-day mortality was 1.1%. Among 490 patients with an IPN, 381 (77.7%) were found to have lung cancer, 41 (8.4%) metastatic cancer, and 68 (13.9%) benign disease. Among patients with pathologic stage IA lung cancer, there was no difference in recurrence rates (14.5% vs 13.9%) or 5-year freedom from recurrence estimates (78% in each group, p=0.738) when comparing segmentectomy and lobectomy.

CONCLUSIONS

Anatomic segmentectomy provides acceptable morbidity and mortality when approaching the IPN. Cancer is identified in 86% of lesions. Complete surgical resection can be achieved with generous parenchymal margins and thorough nodal staging for small, peripheral stage IA non-small cell lung cancer. The use of anatomic segmentectomy should be considered in this era of competing image-guided diagnostic and therapeutic approaches to peripheral lung pathology.

Approach to the ground-glass nodule

The detection of ground-glass opacity (GGO) is increasingly common. Sufficient data have been accumulated to formulate recommendations for observation, intervention, and treatment modalities. However, an understanding of many nuances and uncertainties in the available data is needed to avoid making management errors. This article discusses the range of possible entities, risk factors and characteristics that help make a presumptive clinical diagnosis, how often and for how long these should be followed when and how a biopsy should be done, how these lesions should be treated, and how multifocal GGOs should be approached.

A technique for retrieving a lung lobe in a bag from a small wound during thoracoscopic surgery

We herein describe our technique for removing lung specimens during thoracoscopic resection. This technique allows extraction of intact lung specimens through a small incision. We believe that it is feasible, can be easily and rapidly performed, and facilitates thoracoscopic lung resection by reducing the technical difficulties involved in specimen removal; we also think that it may be used in other thoracoscopic interventions.

Ground-glass nodules on chest CT as imaging biomarkers in the management of lung adenocarcinoma

OBJECTIVE

The purpose of this article is to review the clinical significance of ground-glass nodules (GGNs) in the management of lung adenocarcinoma.

CONCLUSION

GGNs can serve as imaging biomarkers that represent the bronchioloalveolar carcinoma component in adenocarcinoma on histology and indicate a better prognosis in patients with lung adenocarcinoma. The evolution of GGNs reflects the multistep progression of adenocarcinoma. Despite the high probability of malignancy of GGNs, the possibility of overdiagnosis should be considered in the management of GGNs.

Preoperative localization of small peripheral pulmonary nodules by percutaneous marking under computed tomography guidance

The outcome of computed tomography (CT)-guided percutaneous marking for the preoperative localization of small peripheral pulmonary nodules was analyzed retrospectively. This procedure, in which 21-gauge markers were placed near nodules under local anesthesia on the day of surgery, concerned the patients who received video-assisted thoracoscopic surgery as a primary operative technique. The study included all the 57 patients who underwent CT-guided percutaneous marking before pulmonary resection. The mean nodule size was 1.1 cm. Pneumothorax and pulmonary bleeding were observed in 28 and 17 patients, respectively. Other complications included pain (four), subcutaneous bleeding (two) and dislodgment of the marker (one). Wedge resection during thoracotomy was necessary in seven patients because of severe adhesions (four), multiple wedge resections (one), dislodgment of the marker (one) and difficulty in identifying a nodule (one). Pathological studies revealed 24 metastatic lung tumors, 19 bronchioloalveolar carcinomas (BACs), five adenocarcinomas with mixed subtypes, three granulomas, two atypical adenomatous hyperplasias and six miscellaneous others. Wedge resection for malignancy was performed in 39 patients with 41 lesions. The median follow-up period was 46 months. A positive surgical margin and recurrence at the surgical stump were observed in one case each. In conclusion, preoperative CT-guided marking was safe and effective, although marker dislodgment, positive surgical margin and recurrence at the surgical stump were observed infrequently.

A prospective radiological study of thin-section computed tomography to predict pathological noninvasiveness in peripheral clinical IA lung cancer (Japan Clinical Oncology Group 0201)

PURPOSE

Pathological noninvasiveness needs to be precisely predicted in preoperative radiological examinations of patients with early lung cancer for the application of limited surgery.

PATIENTS AND METHODS

Patients with clinical T1N0M0 peripheral lung cancer were recruited. Radiological findings of the main tumor were evaluated as to ground-glass opacity with thin-section computed tomography. The primary end point was specificity, i.e., the proportion of patients with radiologically diagnosed invasive lung cancer to patients with pathologically diagnosed invasive lung cancer. The precision-based planned sample size was 450. We expected that the lower limit of the 95% confidence interval (CI) for specificity should be satisfied in ≥97% of patients.

RESULTS

We enrolled 811 patients from 31 institutions between December 2002 and May 2004. The primary end point was evaluated in 545 patients. The specificity and sensitivity for the diagnosis of pathologically diagnosed invasive cancer were 96.4% (161/167, 95% CI: 92.3-98.7%) and 30.4% (115/378, 95% CI: 25.8-35.3%), respectively, i.e., a negative result. Nevertheless, the specificity for lung adenocarcinoma ≤2.0 cm with ≤0.25 consolidation to the maximum tumor diameter was 98.7% (95% CI: 93.2-100.0%), and this criterion could be used to radiologically define early adenocarcinoma of the lung.

CONCLUSIONS

Although our predetermined criterion for specificity was not statistically confirmed, radiological diagnosis of noninvasive lung cancer with a thin-section computed tomography scan corresponded well with pathological invasiveness. Radiological noninvasive peripheral lung adenocarcinoma could be defined as an adenocarcinoma ≤2.0 cm with ≤0.25 consolidation.

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma

INTRODUCTION

Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies.

METHODS

An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤ 5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized.

CONCLUSIONS

This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.

Anatomic thoracoscopic pulmonary segmentectomy under 3-dimensional multidetector computed tomography simulation: a report of 52 consecutive cases

OBJECTIVE

The purpose of this retrospective study was to evaluate the efficacy of anatomic thoracoscopic pulmonary segmentectomy performed under the guidance of 3-dimensional multidetector computed tomography simulation.

METHODS

Between September 2004 and June 2009, 52 patients (median age, 68 years; range, 16-85 years) underwent thoracoscopic segmentectomy without mini-thoracotomy. Images were obtained by using 64-channel multidetector computed tomography and a contrast agent. The pulmonary arteriovenous structure was mainly determined using a 3-dimensional volume-rendering method. The preoperative simulation was performed at the initial stage of the study and the intraoperative at a later stage. The simulated images were used to identify the venous branches in the affected segment for division and the intersegmental veins to be preserved. Four 5- to 20-mm ports were used. Segmentectomy was performed by separating the pulmonary arteries and bronchi followed by dissection along the intersegmental plane.

RESULTS

Fifty-one patients underwent a complete thoracoscopic segmentectomy. A mini-thoracotomy was performed in 1 case because of arterial bleeding. The success rate of segmentectomies under complete thoracoscopy was 98%. The procedure was classified into 3 categories according to the degree of surgical difficulty. Before introducing the simulation, there were 4 easy cases and 1 fairly difficult case. After introducing preoperative simulation, 7 cases were classified as fairly difficult among 12 segmentectomy cases. Furthermore, 7 cases of difficult segmentectomy were performed using intraoperative simulation. No local recurrence or metastasis and no mortality were observed during the follow-up.

CONCLUSIONS

Thoracoscopic pulmonary segmentectomy under 3-dimensional multidetector computed tomography simulation is a safe technique.

A clinicopathological study of resected non-small cell lung cancers 2 cm or less in diameter: a prognostic assessment

The detection and diagnosis of small-sized (2 cm or less) non-small cell lung cancer (NSCLC) has increased with the development of computed tomography (CT). Over 80% of 5-year survival rate has been reported in surgically treated peripheral lung cancer. There are systematic mediastinal and hilar lymph node involvement pleural invasion and intrapulmonary metastasis even with tumor diameter less than 2 cm. The appropriate surgical procedure for such kinds of lung cancer is lobectomy with mediastinal lymph node dissection. To evaluate the prognostic factors and establish the optimal surgical strategy, we analyzed the clinicopathologic features and survival benefit in different tumor size of peripheral small-sized NSCLC. Among the resected lung cancer cases between January 1999 and July 2001, 185 patients were retrospectively analyzed in surgical methods, lymph node involvement, CT scan findings and survival rates. Survival was analyzed by Kaplan-Meier method and log-rank test. Lymph node involvement was recognized in 26(14.05%) patients. There was no statistically significant difference in the incidence of lymph node involvement between tumors 1.6-2.0 cm (17.82%) in diameter than in those 1.0-1.5 cm (11.94%). There was no lymph node metastasis in tumors less than 1.0 cm in diameter. The 5-year survival rates with or without lymph node involvement were 89.98 and 46.15%, respectively, showing significant difference (P=0.000). The overall 5-year survival rate was 83.78%. The 5-year survival rate in tumors 1.6-2.0 cm, 1.0-1.5 cm and less than 1.0 cm in diameter was 80.20, 85.07 and 100%, respectively, and showing significant difference (P=0.035). The 5-year survival rate of 19 patients showing ground-glass opacity (GGO) on CT scan was 94.74% without any metastasis and recurrence after operation. There are systematic mediastinal and hilar lymph node involvement even with tumor diameter less than 2 cm. The results of the present study suggested that systematic lymph node dissection is necessary even for cases with tumor diameter less than 2 cm. However, if the tumor is within 1.0 cm in diameter with obvious GGO showing on chest CT scan, these are good candidates for partial resection without mediastinal lymph node dissection.

Subcarinal lymph node in upper lobe non-small cell lung cancer patients: is selective lymph node dissection valid?

Little is known about selective lymph node dissection in non-small cell lung cancer (NSCLC) patients. We sought to gain insight into subcarinal node involvement for its frequency and impact on outcome to evaluate whether it is valid to omit subcarinal lymph node dissection in upper lobe NSCLC patients. We reviewed node metastases distribution according to node region, tumor location, and histology among 1099 patients with upper lobe NSCLC. We paid special attention to subcarinal metastases patients without superior mediastinal node metastases, because their pathological stages would have been underdiagnosed if subcarinal node dissection had been omitted. We also assessed the outcome and the pattern of failure among subcarinal metastases patients. To identify subcarinal node involvement predictors, we analyzed 7 clinical factors. Subcarinal node metastases were found in 20 patients and were least frequent among squamous cell carcinoma patients (0.5%). Two of them were free from superior mediastinal metastases but died of the disease at 1 month and due to an unknown cause at 18 months, respectively. Seventeen of the 20 patients developed multi-site recurrence within 37 months. The 5-year survival rate of the 20 patients with subcarinal metastases was 9.0%, which was significantly lower than 32.0% of patients with only superior mediastinal metastases. Clinical diagnosis of node metastases was significantly predictive of subcarinal metastases. Subcarinal node metastases from upper lobe NSCLC were rare and predicted an extremely poor outcome. It appears valid to omit subcarinal node dissection in upper lobe NSCLC patients, especially in clinical N0 squamous cell carcinoma patients.

The accuracy of frozen section diagnosis of pulmonary nodules: evaluation of inflation method during intraoperative pathology consultation with cryosection

INTRODUCTION

Intraoperative frozen section diagnosis (FSD) is a very important pathologic examination that can determine the extent of the subsequent surgical procedure. However, FSD is especially difficult in small pulmonary nodules due to severe architectural distortion during cryosection. This study was undertaken to determine the accuracy of FSD of pulmonary nodules and to evaluate the inflation method during cryosection.

METHODS

We retrospectively reviewed FSD of 229 consecutive pulmonary nodules and evaluated the diagnostic accuracy and efficacy of inflation method during cryosection. Since August 2006, all frozen sections (165, 72.1%) were made after inflation with optimally diluted embedding medium.

RESULTS

The FSD were as follows: nonneoplastic lesions (29, 12.7%), benign neoplasms (28, 12.2%), and malignant neoplasms (172, 75.1%). The proportion of the lesions smaller than 2 cm was 60.3% (138 of 229). The frozen section quality of lung tissue was excellent after inflation with diluted embedding medium. Inflated lung specimens harboring minute lesion displayed distinct gross appearance, which could not be palpated. Histologically, open air spaces and normal parenchymal architectures were well preserved. Minute precancerous foci such as atypical adenomatous hyperplasia and bronchioloalveolar carcinoma could be readily identified. After using inflation method during cryosection, both the sensitivity and specificity reached 100%, and the incidence of intraoperative pathology consultation increased markedly, especially small impalpable lesions.

CONCLUSIONS

The accuracy of FSD and histologic qualities were excellent by using inflation method, especially in cases of impalpable small precancerous lesions. The pathologist could guide with confidence the surgeon in planning the surgical management.

Small peripheral lung adenocarcinoma: clinicopathological features and surgical treatment

The clinical use of high-resolution computed tomography (CT) has greatly advanced diagnosis of small peripheral lesions of the lung. In CT images, these lesions often exhibit ground-glass opacity (GGO). Ground-glass opacity is typical of noninvasive bronchioloalveolar carcinoma (BAC), which is characterized by a lepidic pattern of cells that line the alveoli but do not invade neighboring structures. Bronchioloalveolar carcinoma is classified as a subset of lung adenocarcinoma, but has distinct clinical and pathological features and a favorable prognosis. Most small peripheral lung lesions, including BAC, probably originate in the epithelium of the peripheral airway. As with other subsets of non-small cell lung cancer, surgical resection is a potentially curative treatment. However, it is questionable whether a lobectomy is necessary for small lesions that exhibit GGO, particularly when they are <1 cm in diameter. Although several Japanese investigators have suggested that a limited resection, including a wedge resection and a segmentectomy without nodal dissection, is an appropriate treatment for small lung adenocarcinomas, this approach should be validated by clinical trials.

[Localized pure or mixed ground-glass lung opacities]

Localized ground-glass opacities (GGOs) have been recently individualized and account for between 2.9% and 19% of all pulmonary nodules detected in high-risk patients included in CT screening series for lung cancer. These opacities, nodular, lobular or flat, correspond to benign lesions (localised infectious and inflammatory diseases, focal interstitial fibrosis, and atypical alveolar hyperplasia) or malignant lesions (bronchioloalveolar carcinoma, early-stage adenocarcinoma and sometimes metastases). Localized GGOs are more likely to be malignant than solid nodules and prognosis is related to the percentage of the ground-glass component. However, doubling time of pure localized malignant GGOs is longer than mixed localized malignant GGOs and even longer than the doubling time of solid malignant nodules. Therefore, localized GGOs warrant a dedicated diagnostic workup.

Limited resection for noninvasive bronchioloalveolar carcinoma diagnosed by intraoperative pathologic examination

BACKGROUND

The establishment of limited resection procedures for non-small cell lung cancer is expected. Many groups have suggested noninvasive bronchioloalveolar carcinoma (BAC) to be a potential indication for limited resection.

METHODS

We designed a prospective phase II study evaluating limited resection for noninvasive BAC diagnosed by intraoperative pathologic examination. From 1999 to 2007, limited resection was the procedure in 46 patients (16 men and 30 women; median age, 69 years; range, 49 to 83) who were diagnosed intraoperatively as having noninvasive BAC. The first end point was the predictive value of the intraoperative pathologic examination for noninvasive BAC diagnosis. The second end point was overall survival, disease-free survival, and cancer-specific survival, calculated using the Kaplan-Meier method.

RESULTS

We performed wedge resections for 44 patients and segmentectomy for 2 patients. Permanent pathologic examination revealed 3 patients had primary lung adenocarcinomas other than noninvasive BAC. The predictive value of intraoperative pathologic examination for noninvasive BAC diagnosis was 94%. During a median 51-month follow-up, there were only 2 cancer unrelated deaths. The 5-year overall survival rate and the disease-free survival rate were 93%, and the 5-year cancer-specific survival rate was 100%.

CONCLUSIONS

The results of our prospective phase II study indicate that limited resection, mainly by wedge resection, is a potentially curative surgical procedure and may be an acceptable alternative to lobectomy for patients with noninvasive BAC. Furthermore, an intraoperative pathologic diagnosis of noninvasive BAC is strongly predictive and allows for an intraoperative decision to perform a limited resection in these patients.

Malignant pure pulmonary ground-glass opacity nodules: prognostic implications

Objective

This study was designed to evaluate follow-up results in terms of patient prognosis for malignant pulmonary nodules depicted as pure ground-glass opacity (GGO) lesion observed at high-resolution CT (HRCT).

Materials and Methods

Surgical removal for malignant GGO nodules was accomplished in 58 patients (26 men, 32 women; mean age, 57 years; age range, 29-78 years). Patient prognoses were assessed by patient clinical status and the presence of changes in nodule size determined after a follow-up HRCT examination. Differences in patient prognoses were compared for nodule number, size, surgical method, change in size before surgical removal, and histopathological diagnosis by use of Fisher's exact test and Pearson's chi-squared test.

Results

Of the 58 patients, 40 patients (69%) were confirmed to have a bronchioloalveolar carcinoma (BAC) and 18 patients (31%) were confirmed to have an adenocarcinoma with a predominant BAC component. Irrespective of nodule size, number, treatment method, change in size before surgical removal and histopathological diagnosis, neither local recurrence nor a metastasis occurred in any of these patients as determined at a follow-up period of 24 months (range; 12-65 months). Of 14 patients with multiple GGO nodules, all of the nodules were resected without recurrence in six patients. In the remaining eight patients, the remaining nodules showed no change in size in seven cases and a decrease in size in one case as determined after a follow-up CT examination.

Conclusion

Prognoses in patients with pure GGO malignant pulmonary nodules are excellent, and not significantly different in terms of nodule number, size, surgical method, presence of size change before surgical removal and histopathological diagnosis.

Differential diagnosis of ground-glass opacity nodules: CT number analysis by three-dimensional computerized quantification

OBJECTIVES

To differentiate among atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and adenocarcinoma showing ground-glass opacity (GGO) on CT scans, we conducted a study to determine the optimal parameter on CT number analysis using three-dimensional (3D) computerized quantification.

METHODS

From the CT numbers of GGO lesions obtained by 3D computerized quantification, CT number histogram pattern, peak CT number on the histogram, mean CT number, and the 5th to 95th percentile CT numbers were analyzed to determine the optimal parameter for differentiation among AAH (n = 10), BAC (n = 21), and adenocarcinoma (n = 12).

RESULTS

While the CT number histogram showed one peak in all 10 of the AAH lesions (100%), it showed two peaks in 8 of 21 BAC lesions (38%), and in 5 of 12 adenocarcinoma lesions (42%). For differentiation between AAH and BAC, the 75th percentile CT number with a cutoff value of -584 Hounsfield units (HU) was optimal, with a sensitivity of 0.90 and a specificity of 0.81. For differentiation between BAC and adenocarcinoma, a mean CT number with a cutoff value of -472 HU was optimal, with a sensitivity of 0.75 and a specificity of 0.81.

CONCLUSIONS

From the analysis of CT numbers of GGO lesions obtained by 3D computerized quantification, we conclude the following: (1) two peaks on the CT number histogram can rule out AAH; (2) the 75th percentile is the optimal CT number for differentiating between AAH and BAC; and (3) the mean CT number is the optimal CT number for differentiating between BAC and adenocarcinoma.

Controversy about Small Peripheral Lung Adenocarcinomas: How Should We Manage Them?

In recent years, the clinical use of high-resolution computed tomography has greatly advanced the diagnosis of small lesions of the peripheral lung. Such small lesions are often associated with ground-glass opacity in computed tomography findings. The noninvasive bronchioloalveolar carcinoma component with a replacement growth pattern of alveolar lining cells manifests as ground-glass opacity. Bronchioloalveolar carcinoma is classified as a subset of lung adenocarcinoma, but has a distinct clinical presentation, tumor biology, and favorable prognosis. Most small peripheral lung lesions including bronchioloalveolar carcinoma putatively originate from the peripheral airway epithelium, in which the epidermal growth factor receptor gene is frequently mutated. As with other subsets of non-small cell lung cancer, surgical resection is a potentially curative treatment. For the ground-glass opacity type of tiny lesions, particularly those less than 1 cm in their greatest dimension, the question has been raised whether lobectomy is really needed. Although several authors in Japan suggest the suitability of limited resection including segmentectomy and wedge resection without any nodal dissections for these small lung adenocarcinomas, this procedure should be validated in future clinical trials.

Management of the Peripheral Small Ground-Glass Opacities

Pure ground-glass opacities (GGO) with a small consolidation area are mostly bronchioloalveolar carcinomas that have not yet become invasive, whereas a minority represents only inflammatory changes. Even if they are cancers, they are slow-growing and often remain unchanged for several years. There is no need for immediate resection of GGO lesions and a watchful waiting strategy is recommended. It seems that a lower-impact surgery (eg, wedge resection or segmentectomy) is curative for these lung cancers. Because high-resolution CT seems to predict noninvasive or minimally invasive GGO lung cancers with high reliability, less invasive treatments like radiofrequency ablation have greater appeal.

Nodular ground-glass opacities on thin-section CT: size change during follow-up and pathological results

OBJECTIVE

To evaluate the inter-group differences in growth and the pathological results of nodular ground-glass opacities (GGOs) according to their size and focal solid portions.

MATERIALS AND METHODS

Ninety-six nodular GGOs in 55 individuals followed by CT for at least one month from an initial chest CT were included. Forty nodular GGOs in 30 individuals were pathologically confirmed to be: adenocarcinoma (n = 15), bronchioloalveolar carcinoma (BAC) (n = 11), atypical adenomatous hyperplasia (AAH) (n = 8), focal interstitial fibrosis (n = 5) and aspergillosis (n = 1). Lesions were categorized based on high-resolution CT findings: pure nodular GGO (PNGGO) < or = 10 mm, PNGGO > 10 mm, mixed nodular GGO (MNGGO) < or = 10 mm, and MNGGO > 10 mm. In each group, the change in size during the follow-up period, the pathological results and the rate of malignancy were evaluated.

RESULTS

Three MNGGO lesions, and none of the PNGGO, grew during the follow-up period. Resected PNGGOs < or = 10 mm were AAH (n = 6), BAC (n = 5), and focal interstitial fibrosis (n = 1). Resected PNGGOs > 10 mm were focal interstitial fibrosis (n = 4), AAH (n = 2), BAC (n = 2), and adenocarcinoma (n = 2). Resected MNGGOs < or = 10 mm were adenocarcinoma (n = 2), and BAC (n = 1). Resected MNGGOs > 10 mm were adenocarcinoma (n = 11), BAC (n = 3), and aspergillosis (n = 1).

CONCLUSION

Mixed nodular GGOs (MNGGOs) had the potential for growth; most were pathologically adenocarcinoma or BAC. By contrast, PNGGOs were stable for several months to years; most were AAH, BAC, or focal interstitial fibrosis.

Impalpable pulmonary nodules with ground-glass opacity: Success for making pathologic sections with preoperative marking by lipiodol

BACKGROUND

The developments in high-resolution CT scanning have increased the chance of detecting small bronchioloalveolar carcinoma (BAC) or atypical adenomatous hyperplasia (AAH) that appears as a ground-glass opacity (GGO). However, these lesions are not only difficult to localize during surgery, but they are also hard to make pathologic sections of because they are usually impalpable. Here, we report a method of making pathologic sections for impalpable GGO lesions.

METHODS

Twenty-nine impalpable GGO lesions < 1 cm in size were marked by 0.4 to 0.5 mL of lipiodol under CT scan before surgery. The lesions were resected under C-arm fluoroscopy. The radiopaque areas marked by lipiodol within the formalin-fixed specimens were cut serially under conventional fluoroscopy for pathologic examinations.

RESULTS

The mean (+/- SD) size of the lesions was 0.5 +/- 0.2 cm (range, 0.2 to 1 cm), and the mean depth from the pleural surface was 1.6 +/- 1.4 cm (range, 0.2 to 6 cm). The mean number of sections submitted for pathologic examinations was 2.3 +/- 1.7 per lesion (range, 1 to 7 per lesion). While 11 of the 29 lesions (38%) were invisible even on the cut surface of the specimens, all were demonstrated in hematoxylin-eosin sections. The pathologic diagnosis was BAC in 17 lesions, AAH in 10 lesions, and organized pneumonia in 2 lesions. The use of lipiodol did not affect the pathologic findings.

CONCLUSIONS

The use of fluoroscopy to cut sections from resected specimens after preoperative marking with lipiodol was useful for making pathologic sections of impalpable GGOs < 1 cm in size.

Focal interstitial fibrosis manifesting as nodular ground-glass opacity: thin-section CT findings

The purpose of this study was to describe the thin-section computed tomographic (CT) features of focal interstitial fibrosis manifesting as nodular ground-glass opacity (GGO) and its changes during follow-up. The thin-section CT findings of pathologically proven focal interstitial fibrosis manifesting as nodular GGO were retrospectively evaluated in nine patients (five women and four men; mean age, 59.3 years; age range, 34-81 years). The thin-section CT findings of each lesion were analyzed for multiplicity, location, shape, margin characteristics, pleural retraction or vascular convergence, size and internal attenuation, lesion internal features and lesion changes on follow-up CT scans (mean 90 days, range 5 to 215 days). All lesions manifested as a solitary nodular GGO (100%), and seven of the nine lesions (77.8%) were located in the upper lobe. Focal interstitial fibrosis was round or oval in shape in five cases (55.6%), complex in shape in three cases (33.3%) and polygonal in one case (11.1%). Lesion margins were smooth in five patients (55.6%), irregular in three (33.3%) and spiculated in one (11.1%). Pleural retraction or vascular convergence was present in two patients (22.2%). Lesions measured 4.8 mm to 25.5 mm (mean, 11.5 mm) and had attenuations ranging from -151 to -699 HU (mean, -514.7 HU). Eight (88.9%) manifested as pure nodular GGOs and one as mixed GGO with a spiculated margin. In all patients, no lesion changes were observed in follow-up CT scans. Focal interstitial fibrosis manifesting as nodular GGO usually presents as a solitary nodule with pure GGO on thin-section CT, which does not change significantly during follow-up.

Clinicopathologic study of resected, peripheral, small-sized, non–small cell lung cancer tumors of 2 cm or less in diameter: Pleural invasion and increase of serum carcinoembryonic antigen level as predictors of nodal involvement

OBJECTIVE

The number of surgical interventions for small-sized lung cancer has increased with the development of computed tomography. We attempted to identify clinicopathologic characteristics of peripheral, small-sized, non-small cell lung cancer to show the limitation of partial resection or segmentectomy.

METHODS

A retrospective analysis of 143 patients who underwent a complete resection for a peripheral non-small cell lung cancer of 2 cm or less in diameter was performed. The relationships between nodal involvement and other clinical factors were also assessed in patients who underwent a lobectomy plus node dissection.

RESULTS

The overall 5-year survival rate was 88.1%. The 5-year survival rate was 100% for patients with a tumor of 1.5 cm or less. Survival for patients with adenocarcinoma histology was significantly better than for those with nonadenocarcinoma histology (P = .03). The 5-year survival rate for patients without lymph node metastases was 91.6%, whereas it was 62.5% for those with nodal involvement (P < .01). Increase of prethoracotomy serum carcinoembryonic antigen level was an independent predictor of a poor prognosis. Lymph node metastasis was significantly increased in those with pleural invasion by the primary lesion and increased serum carcinoembryonic antigen level. Fourteen (16.9%) of 83 patients with a tumor diameter of larger than 1.5 cm had nodal metastasis.

CONCLUSIONS

Nodal involvement should be considered in patients with non-small cell lung cancer of 2 cm or less in diameter who show pleural invasion or an increased carcinoembryonic antigen level. A lobectomy with node dissection is recommended for patients with a tumor larger than 1.5 cm, suspected pleural invasion, or prethoracotomy carcinoembryonic antigen level increase.