Atypical adenomatous hyperplasia of the lung: a clinicopathological study of 118 cases including cases with multiple atypical adenomatous hyperplasia

BACKGROUND: Atypical adenomatous hyperplasia (AAH) of the lung is a putative precursor lesion of adenocarcinoma, according to many immunohistochemical and genetical studies, but few clinicopathological studies on a large number of cases have been reported. The aim of this study was to clarify the clinicopathological characteristics of lung cancer patients with AAH lesions. METHODS: A retrospective study was carried out on 508 consecutive primary lung cancer patients operated on at National Cancer Center Hospital East. The relationship between the number and location of AAH lesions and the clinicopathological features of the lung cancer patients was analysed statistically. RESULTS: A total of 311 AAH lesions were found in 118 (23.2%) of the 508 cases. AAH lesions were detected in 121 of 572 lobes examined, usually in both upper lobes, and occurred most frequently in patients with adenocarcinoma (OR 2.97; 95% CI 1.82 to 4.85). AAH lesions were more frequently detected in patients with multiple primary carcinomas than in those with a single carcinoma (OR 3.06; 95% CI 1.56 to 6.00). The presence of AAH lesions was not significantly correlated with sex, age, smoking status, familial history of malignancy, or preceding malignancy. Patients with multiple AAH lesions were found to have a significantly higher frequency of preceding malignancies. CONCLUSIONS: The present study highlights the clinicopathological characteristics of AAH lesions, showing them to be significantly associated with both adenocarcinoma and multiple primary carcinoma of the lung and suggesting common factors in the histogenesis of multiple AAH lesions and preceding malignancy.     

Expression of alpha-Methylacyl-CoA racemase (P504S) in atypical adenomatous hyperplasia of the prostate

Atypical adenomatous hyperplasia (AAH) of the prostate, also known as adenosis, is characterized by a proliferation of prostatic glands with abnormal architectural patterns, but without significant cytologic atypia. In some cases it may be difficult to distinguish AAH from prostatic carcinoma. Additionally, it is not clear whether AAH is a precursor lesion of prostatic adenocarcinoma. P504S, a protein highly expressed in prostatic adenocarcinoma, has been recently shown to be a marker of prostate cancer. The goal of this study is to examine the expression of P504S in AAH by immunohistochemistry. A total of 80 prostate specimens, including 40 cases of AAH (prostatectomy N = 30, biopsy N = 6, transurethral resection N = 4), 20 cases of prostatic adenocarcinomas, and 20 cases of benign prostatic hyperplasia, were studied. Immunohistochemistry for a prostate cancer marker alpha-methylacyl-CoA racemase (P504S) and a basal cell-specific marker 34betaE12 was performed in all the cases. The 34betaE12 stain confirmed the presence of patchy basal cells in all 40 cases of AAH. P504S was undetectable in the majority of AAHs (33 of 40, 82.5%), focally expressed in four of 40 (10.0%), or diffusely positive only in three of 40 (7.5%) cases of AAH. Interestingly, two of seven P504S-positive AAHs were found adjacent to adenocarcinoma. In contrast, all benign prostatic hyperplasias (20 of 20, 100%) were negative for P504S, and all 20 cases of prostatic carcinomas (100%) showed a diffuse P504S staining pattern. These findings suggest that AAH is a heterogenous entity. The biologic significance of P504S expression in a small subset of AAH remains to be determined. Because most cases of AAH are negative for P504S, immunostaining of P504S is also of diagnostic value in distinguishing the majority of AAHs from prostatic adenocarcinoma.     

Associations among benign prostate hypertrophy, atypical adenomatous hyperplasia and latent carcinoma of the prostate

Aim： To investigate the frequency of atypical adenomatous hyperplasia （AAH） and its associations with benign prostate hypertrophy （BPH） and latent histological carcinoma of the prostate （LPC） in autopsy material. Methods： Two hundred and twelve prostate specimens obtained from autopsy material were subjected to whole mount analysis in an attempt to investigate the associations among BPH, AAH and LPC. Results： Most histological carcinomas and AAH lesions were found in enlarged prostates with intense hypertrophy. No statistically significant relation was found between BPH and the main characteristics of LPC, such as tumor volume, histological differentiation and biological behavior. Our data regarding multi-focal tumors showed a tendency for multi-focal carcinomas to develop in larger prostates, and a tendency of AAH lesions to develop in larger prostates. No statistically significant relation was found between AAH and LPC. Conclusion： There seems not any causative aetiopathogenetical or topographical relation between AAH lesions and prostate adenocarcinoma. AAH lesion seems to be a well-defined mimicker of prostatic adenocarcinoma, and the reported association of AAH with prostatic carcinoma could probably be an epiphenomenon.     

Acute adrenal haemorrhage: Diagnosis,treatment and follow-up

Acute adrenal haemorrhage (AAH) is a rare disorder with different aetiologies. Aiming to discuss this condition, this report deals with four different cases that will be analysed and examined below, each one of them confirmed by biopsy or surgery and followed clinically and radiologically. In these cases it was found that the patients suffered from localized abdominal pain (4/4) and fever (2/4); one patient had adrenal insufficiency due to bilateral massive AAH. Therefore we concluded that AAH is an uncommon condition with variable clinical manifestations.     

The impact of acute alcoholic hepatitis in the explanted recipient liver on outcome after liver transplantation.

Patients with clinical acute alcoholic hepatitis (AAH) are not considered suitable candidates for orthotopic liver transplantation (OLT). The histological correlates of AAH are often seen in the explanted liver at the time of transplantation. The importance of these findings remains inconclusive regarding their role as a prognostic marker for patient or allograft health. Our aim was to examine the explanted liver of patients with purely alcoholic liver disease (ALD) for findings of histologic AAH and to correlate these to patient and graft outcomes. We compared patients with and without histological AAH with patients transplanted for non-ALD. Of 1,097 liver transplant recipients, 148 had ALD and 125 were non-ALD control patients with similar demographics. Thirty-two of 148 ALD patients had histologic AAH, and 116 had bland alcoholic cirrhosis (BAC). Twenty-eight percent of the ALD patients reported <6 months abstinence, and 54% reported <12 months abstinence. There was a statistically significant relationship between the presence of histologic AAH and abstinence durations<12 months (P=0.009), but not <6 months. Overall, posttransplantation patient and graft survival between the ALD and non-ALD groups was not significantly different (P=0.53). Furthermore, patient and graft survival between ALD patients with histologic AAH and BAC were similar (P=0.13 and P=0.11, respectively). The rate of posttransplantation relapse among ALD patients was 16%; however, there was no increase in graft loss, nor was there decreased survival compared with controls. The patients with histologic AAH and those with BAC had no differences in posttransplantation relapse (P=0.13). In multivariate analysis, patient and graft survival was not influenced by pretransplantation abstinence or posttransplantation relapse. In conclusion, histological alcoholic hepatitis in the explant did not predict worse outcome regarding relapse, and allograft or patient survival for liver transplant recipients. Caution should be exercised when liver histology is used to discriminate among suitable candidates for OLT concerning alcoholic patients.     

Differentiating between atypical adenomatous hyperplasia and bronchioloalveolar carcinoma using the computed tomography number histogram

BACKGROUND: Both atypical adenomatous hyperplasia (AAH) and bronchioloalveolar carcinoma (BAC) appear as ground glass opacity (GGO) lesions by computed tomography (CT) and are sometimes difficult to differentiate. To aid distinction between the two, we examined their CT number histograms. METHODS: Histograms of pixel CT numbers were made for AAH (n = 9) and nonmucinous BAC (n = 8), and the peak and mean CT numbers on the histogram were quantified. RESULTS: Although there was no significant difference in lesion size between AAH and BAC, all AAHs were less than or equal to 1 cm in diameter. All AAHs and BACs manifested one histogram peak. Both the peak and mean CT numbers on the histogram were significantly lower for AAH than for BAC (p < 0.001). However, the degree of overlap between AAH and BAC was less for the peak CT number than for the mean CT number. CONCLUSIONS:The peak CT number on the histogram can help the radiologic differentiation between AAH and BAC. GGO lesions less than or equal to 1 cm in diameter that are diagnosed as AAH from the CT number histogram can be safely followed by CT.     

Aortic arch advancement: the optimal one-stage approach for surgical management of neonatal coarctation with arch hypoplasia

BACKGROUND: The optimal surgical treatment for neonatal coarctation with aortic arch hypoplasia (NCoAo/AAH) is controversial. Important long-term concerns include arch growth. We report our results obtained with a one-stage radical approach of coarctectomy and aortic arch advancement for NCoAo/AAH. METHODS: From June 1995 to December 2000, 65 newborns with NcoAo/AAH underwent coarctectomy and aortic arch advancement via a median sternotomy under deep hypothermic circulatory arrest. Patients were classified by diagnosis: group 1, isolated NCoAo/AAH (n = 13); group 2, NCoAo/AAH with ventricular septal defect (n = 20); and group 3, NCoAo/AAH with complex cardiac lesions (n = 32). RESULTS: The study population included 36 boys and 29 girls. Mean age was 13 +/- 1.7 days (range 1 to 43 days). Mild to moderate left ventricular outflow tract obstruction was present in 15 patients. Mean body weight was 3.4 +/- 0.1 kg (range 1.6 to 5 kg). Eight babies were premature. The mean Z value for the aortic arch was -4 +/- 0.3 (range -2 to -4.5) and for the isthmus -4.5 +/- 0.2 (range -3 to -7). Mean deep hypothermic circulatory arrest time was 28 +/- 2 minutes (range 14 to 60 minutes). Mean intensive care unit stay was 6 +/- 1 days (range 2 to 30 days). There were three early deaths (all in groups 2 and 3) and two late deaths (in group 3) (5-year actuarial survival, 91% +/- 7.9%). There was one recurrence (5-year actuarial freedom from recurrence, 98% +/- 4%). Peak Doppler velocity across the arch in the remaining patients was 1 +/- 0.1 m/s (range 0 to 2.2 m/s). CONCLUSIONS: Coarctectomy and aortic arch advancement is the optimal surgical method for management of NCoAo/AAH. It has low operative morbidity and mortality and a very low incidence of recoarctation or arch obstruction.     

A clinicopathological study of resected pulmonary nodules with focal pure ground-glass opacity.

OBJECTIVE: Pulmonary lesions with focal ground-glass opacity (GGO) have been detected increasingly by low-dose helical computed tomography (CT). However, the strategy of treatment for focal pure GGO lesions is still undecided. This study evaluates clinicopathological characteristics of resected pulmonary nodules with focal pure ground-glass opacity. METHODS: Between January 1997 and December 2005, 26 patients (35 lesions) with pure GGO lesions underwent pulmonary resection. The data on patient age, lesion size, pathology, carcinoembryonic antigen (CEA) level and palpability of the tumor in the resected specimen were evaluated. RESULTS: The histological diagnosis was bronchioloalveolar carcinoma (BAC) in 10 patients (12 lesions), atypical adenomatous hyperplasia (AAH) in 15 patients (22 lesions), and focal scar in 1 patient (1 lesion). There were no significant differences in age, sex, tumor size, and CEA level between the patients with BAC, AAH, and focal scar. However, the lesions >10mm in size were all BAC. Palpability of the tumor in the resected specimen was significantly more frequent in BAC cases than in AAH cases (p<0.01). For BAC, lobectomy was performed for four lesions, and limited resection for eight. None of the BACs showed lymphatic or vascular invasion upon pathological examination. At the median follow-up point of 44 months (range: 4-84 months), no recurrences were observed. CONCLUSIONS: BAC and AAH cannot be discriminated by their size. In the resected specimen, BAC lesions are more frequently palpable than AAH lesions. Thoracoscopic surgery is recommended for focal pure GGO after repeated CT even if the GGO lesion is small. Partial resection is a sufficient treatment for pure GGO.     

Extra-anatomic aortic bypass for complex (re-) coarctation and hypoplastic aortic arch in adolescents and adults

Various surgical approaches have been proposed for complex (re-) coarctation and aortic arch hypoplasia (AAH). We report seven patients (mean age 19.6+/-9.5 years) with complex coarctation or re-coarctation and AAH successfully treated by extra-anatomic ascending-to-descending aortic bypass (ADB) via sternotomy between 1995 and 2002 without mortality and no relevant complication early postoperatively and during a follow-up of 24+/-29 (0.2-84) months. ADB may therefore be considered in selected patients with (re-) coarctation with AAH, with the need for concomitant ascending aortic or cardiac surgery and in patients with aortic arch stenosis and increased risk of complications under DHCA.     

Ground-glass opacities showing an adenoma-to-carcinoma sequence in the lung

We encountered a patient with three left lower lobe pulmonary tumors evident as discrete ground-glass opacities by computed tomography. Pathological diagnoses of the resected lesions included a focus of atypical adenomatous hyperplasia (AAH) and two localized noninvasive bronchioloalveolar carcinomas (BACs) of types A and C according to Noguchi's classification. This case supports the hypothesis of an adenoma-to-carcinoma sequence in the lung, as the coexisting lesions represented sequential adenocarcinoma progression from a precancerous lesion, AAH, to very early-stage adenocarcinoma, noninvasive BAC.     

前列腺癌组织中嗜银核仁组成区计数的计数

目的：探讨嗜银核仁组成区（argyrophilic nucleolar organizer regions,AgNOR)计数与前列腺癌（PCa)生物学行为及预后的关系。方法：采用Plotn法对PCa、不典型前列腺增生（AAH）、良性前列腺增生（BPH）及正常前列腺（NP）组织进行硝酸银染色,所得AgNOR颗粒采用图像分析仪按Crocker法进行半定量分析。结果：在PCa中AgNOR计数显著高于AAH、BPH及NP;AAH的AgNOR计数介于BPH与PCa之间;在PCa中随肿瘤组织学分级的上升AgNOR计数逐渐上升,且差异有显著性意义;生存期＜3年的PCa病例的AgNOR计数显著高于生存期＞3年的病例,差异也有显著性意义。结论：AgNOR计数有助于鉴别前列腺良、恶性疾病,AAH有一定恶性倾向,AgNOR计数有助于PCa生物学行为及预后的估计。     

Alcohol Abstinence and Orthotopic Liver Transplantation in Alcoholic Liver Cirrhosis

Patients diagnosed with acute alcoholic hepatitis (AAH) are routinely managed medically and not considered suitable for orthotopic liver transplantation (OLT). The eligibility for OLT in these patients has been questioned due to the social stigma associated with alcohol abuse, based on the fact that AAH is “self-induced” with an unacceptably high recidivism rate. Many centers in Europe and the United States require abstinence periods between 6 and 12 months before OLT listing. AAH outcomes in the literature are poor, in particular due to patient noncompliance during the immediate 3 months preceeding OLT. Between January 1997 and December 2007, 246 patients were evaluated in our center for alcoholic liver disease: 133 (54%) were listed for OLT (I-OLT), including 110 (83%) who underwent transplantation and 8 (6%) still listed as well as 15 (11%) removed from consideration. One hundred thirteen (46%) patients had no indication for OLT (NO I-OLT), including 18 (16%) who died, 81 (71%) still monitored, and 14 (12%) lost to follow-up. Patient survival rates post-OLT were 79%, 74%, 68%, and 64% at 1, 3, 5, and 10 years, respectively. Explant (native liver) pathologic examination revealed AAH in 8 (7.2%) patients who underwent OLT. In this group, patient survival and the post-OLT recidivism rate were statistically identical to the overall group of transplant recipients.     

The significance of associated pre-invasive lesions in patients resected for primary lung neoplasms.

OBJECTIVE: To evaluate the prevalence and clinico/prognostic significance of the presence of pre-invasive lesions in patients resected for primary lung neoplasm. METHODS: From 1993 to 2002, 1090 patients received resection for primary lung carcinomas. Of these, 73 presented an associated pre-invasive lesion in the surgical specimen distant from the primary tumour. Classification of pre-invasive lesions included Atypical Adenomatous Hyperplasia (AAH); Carcinoma In Situ (CIS) either diffuse or at the bronchial resection margin; Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH). Correlation between the presence of pre-invasive lesion and the following variables were calculated by logistic regression analysis: sex, age, median tumour size, histology, histologic differentiation, histologic evidence of invasiveness (vascular and perineural invasion), peritumoural lymphocytic infiltrate, pTNM, lobe location, history of previous malignancy. Survival rates were computed using Kaplan-Meier method and survival differences with the total patient population of resected lung carcinomas were tested using the log-rank method. RESULTS: There were 28 AAH, 42 CIS (5 at the bronchial resection margin) and 3 DIPNECH. Histology of the primary tumor included bronchioloalveolar carcinoma (9 patients), adenocarcinoma (19), squamous cell carcinoma (39), typical carcinoid tumour (3) and adenosquamous carcinoma (3). Overall prevalence of pre-invasive lesion was 6.7%. A strong correlation was found between the presence of AAH and the co-existence of either adenocarcinoma, bronchioloalveolar carcinoma or mixed adenocarcinoma-containing tumours (P = 0.00002) between CIS and squamous cell carcinoma (P = 0.009) and between DIPNECH and carcinoid tumours (P = 0.001). No significant correlation was found between the presence of any type of pre-invasive lesion and sex, age, median tumour size, histologic differentiation, histologic evidence of invasiveness, pTNM, lobe location and history of previous malignancy or the probability to develop a second primary lung carcinoma in the remaining lobe(s) after resection. Survival rates in the patients with AAH and CIS were not significantly different from those of patients without pre-invasive lesion (P = 0.3 and P = 0.1). CONCLUSIONS: Associated pre-invasive lesions in patients resected for primary lung neoplasms are not infrequent. AAH is associated with adenocarcinoma, CIS with squamous cell carcinoma, DIPNECH with typical carcinoid tumours. Our experience indicates that in these patients histology, stage distribution and survival do not differ from the total population of resected patients with lung tumors.     

术中冰冻病理对肺结节胸腔镜手术切除范围的指导意义

目的探讨肺结节术中冰冻病理与术后病理判断浸润范围上的一致性,明确术中冰冻病理是否可以协助术者确定肺结节手术切除的范围。方法2017年1月~2018年6月电视辅助胸腔镜手术切除肺结节156例,分析术中冰冻病理与术后病理的诊断符合率。结果术中冰冻病理诊断非典型腺瘤样增生(atypical adenomatous hyperplasia,AAH)、原位腺癌(adenocarcinoma in situ,AIS)及微浸润腺癌(minimally invasive adenocarcinoma,MIA)103例,浸润性腺癌(invasive adenocarcinoma,IA)53例;术后病理证实AAH、AIS及MIA 106例,IA 50例。根据病灶侵袭性、复发及转移的风险程度将AAH、AIS、MIA定义为低风险病灶,IA定义位为高风险病灶。术中冰冻病理诊断高风险病灶敏感性98.0%(49/50),特异性96.2%(102/106),准确率96.8%(151/156)。术中冰冻病理诊断低风险病灶预测值99.0%(102/103),高风险病灶预测值92.5%(49/53)。结论术中冰冻病理在判断IA方面具有较高的诊断符合率,在准确区别AAH与AIS和AIS与MIA存在不确定性。在肺结节手术切除范围的制定上,术中冰冻病理可以作为重要的指导依据。     

Recurrence of hepatocellular carcinoma: multicentric occurrence or intrahepatic metastasis? A viewpoint in terms of pathology

Recurrence after successful surgical or nonsurgical treatment of hepatocellular carcinoma (HCC) is caused either by intrahepatic metastasis or by metachronously multicentric occurrence. Intrahepatic metastasis is a major cause of recurrence of advanced HCCs with varying degrees of vascular invasion, and multicentric occurrence is a frequent cause of recurrence in small HCCs with no obvious vascular invasion. It is estimated that at least 20% of small HCCs have a high probability of recurrence due to multicentric occurrence, based on the finding that adenomatous hyperplasia (AH) and/or atypical adenomatous hyperplasia (AAH), which are considered premalignant lesions, are found in the vicinity of resected small HCCs with liver cirrhosis. However, because neither AH nor AAH occur in HCC cases without liver cirrhosis, most recurrence of HCC in noncirrhotic liver is considered to be due to intrahepatic metastasis or to de novo hepatocarcinogenesis. In a survey of autopsy cases of liver cirrhosis with small HCC, smaller HCC nodules were found in other liver slices in 50% of cases, and it is estimated that approximately 50% of HCC is already multicentric in the early stage. Received: February 14, 2001 / Accepted: March 24, 2001     

Poverty as a situation of disability: Social workers’ reticence to back active solidarity income beneficiaries’ requests for disabled adults allowance

Social service support for beneficiaries of the French RSA (minimum income scheme) is based on reducing their problems to a series of situations blocking their “plans to return to employment”. These situations are defined in practice by the specific “programs” toward which professional may orient beneficiaries. This notion is quite close to that of “situation of disability”, as it is used in social conceptions of disability. It is the support for a specific handicapology, rooted in a representation of social service work in rupture with the traditional notion of support for disabled persons, those unfit for work. It is characterized particularly by a refusal to sort beneficiaries into overarching categories, and a change in the meaning given to people's material and cultural destitution, which is not treated as a consequence of unemployment or as a disability, but as a disabling situation responsible for their withdrawal from the employment market. These professional norms are manifest in a strong resistance when beneficiaries express the desire to seek AAH (disabled adult allowance). This reticence is explained by the simultaneous transformations of both the administrative division of social support work and the social trajectories of the social workers charged with this work. AAH requests place professionals in a paradoxical situation: their general role to support people in their administrative procedures comes into contradiction with their mission to “support toward employment”, which they find radically incompatible with the posture of assistance implied by the recognition of even a partial unfitness for work.     

One-dimensional mean computed tomography value evaluation of ground-glass opacity on high-resolution images

Objective  

Differentiation of atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and invasive carcinoma on computed tomography (CT) is useful for determining “follow-up or resection” strategies for lesions displaying ground-glass opacity (GGO). The purpose of this study is to evaluate one-dimensional quantitative CT values of GGO on high-resolution CT (HRCT) images using computer-aided diagnosis.     

Role of cooling and drying in hyperventilation induced asthma.

Respiratory heat loss has been proposed as a mechanism of exercise induced asthma. Whether the predominant stimulus is airway drying or cooling remains unclear. We have measured changes in FEV1 after isocapnic cold air hyperventilation (CAH) (-23.4 degrees (SD 0.43 degrees) C) and dry ambient air hyperventilation (AAH) (18.7 degrees (0.52 degrees)C) in seven asthmatic patients (mean age 31 (SD 9) years and baseline FEV1 3.2(0.9)1) and in seven normal subjects (age 28(6) years and FEV1 3.6(0.7)1). The inspired water content in both cases was 0.3 mg/l air. The rate of respiratory heat exchange per breath was calculated in watts (W) with microcomputer based equipment. Cold air hyperventilation caused a fall in FEV1 almost twice that of ambient air hyperventilation at each level of ventilation: CAH v AAH (% fall) 8.0 (5.1) v 3.9 (4.0) at 15 l/min, 11.6 (7.8) v 7.0 (4.4) at 30 l/min, and 20.7 (10.9) v 12.4 (6.3) at 60 l/min. Identical latent heat loss (evaporative drying) was imposed on the airway during the two challenges. Sensible heat loss (convective cooling) in cold air hyperventilation was 41 W at 15 l/min, 63 W at 30 l/min, and 114 W at 60 l/min; whereas in ambient air hyperventilation the loss was 6, 13, and 23 W respectively. It is concluded that the rate of cooling of the upper airway is the predominant stimulus in hyperventilation induced asthma.     

Prospective study of thoracoscopic limited resection for ground-glass opacity selected by computed tomography

BACKGROUND: With recent advances in low-dose helical computed tomography (CT), detection of ground-glass opacity (GGO) has increased. The aim of this study was to correlate high-resolution CT (HRCT) findings with pathologic features and to evaluate the efficacy of thoracoscopic limited resection for focal GGO, which were selected based on HRCT findings. METHODS: Focal GGO lesions were classified into two subtypes based on HRCT findings: pure type and mixed type. Ninety-six patients with persistent GGO 2 cm or less in diameter underwent pulmonary resection from January 1997 to December 2001. Among these, thoracoscopic wedge resection was performed prospectively between June 2000 and December 2001 in 33 patients with pure GGO lesions that were 1 cm or less. RESULTS: Thoracoscopic wedge resection was completed with complete safety. The histologic diagnoses of these 33 lesions were adenocarcinoma in 1, bronchioloalveolar carcinoma (BAC) in 23, and atypical adenomatous hyperplasia (AAH) in 9. No patients have had any evidence of tumor recurrence to date. Of the total 96 GGO lesions, 93.0% (53/57) of pure GGO 1 cm or less were BAC or AAH, whereas 38.5% (15/39) of pure GGO larger than 1 cm or mixed GGO were adenocarcinoma. CONCLUSIONS: Pure GGO 1 cm or less was characteristic of noninvasive lesions. Thoracoscopic limited resection for small GGO lesions selected by HRCT was valid.