Cases Of Atypical Adenomatous Hyperplasia Research Articles

CT-based radiomics analysis for prediction of pathological subtypes of lung adenocarcinoma

ObjectiveLung cancer is a leading cause of cancer-related deaths worldwide, and its early and accurate diagnosis is crucial for improving patient survival. This paper developed an artificial intelligence (AI) model based on machine learning combined with radiomics for predicting the pathologic type of ground glass nodules (GGN). It explored its potential and challenges in practical applications. MethodsA total of 179 GGN patients with postoperative pathologically confirmed lung adenocarcinoma from June 2022 to June 2024 were collected from a hospital, including 22 cases of atypical adenomatous hyperplasia (AAH), 61 cases of adenocarcinoma in situ (AIS), 55 cases of invasive adenocarcinoma (IAC), and 41 cases of minimally invasive adenocarcinoma (MIA). Two experienced radiologists outlined the imaging data's regions of interest (ROI). Radiomic features were extracted and selected through normalization, mutual information, Spearman correlation coefficient, recursive feature elimination, and LASSO regression. Different machine learning models were developed and the best model was determined based on classification accuracy. ResultsDifferent machine learning models were trained and tested, and a variety of deep learning models were selected for comparison, among which Random Forest had the highest accuracy of 83.3%, and the AUC value of 0.892(95%CI, 0.846-0.923) in recognizing lung adenocarcinoma types. The AUC values reached 0.92 and 0.94 respectively in diagnosing AIS and IAC. ConclusionRadiomics combined with machine learning models, such as Random Forest, outperform average physician diagnostic accuracy in identifying lung adenocarcinoma types. The model is valuable for early and precise lung adenocarcinoma diagnosis, enhancing clinical decision-making.

Evaluation of the invasiveness of pure ground-glass nodules based on dual-head ResNet technique

ObjectiveTo intelligently evaluate the invasiveness of pure ground-glass nodules with multiple classifications using deep learning.MethodspGGNs in 1136 patients were pathologically confirmed as lung precursor lesions [atypical adenomatous hyperplasia (AAH) and adenocarcinoma in situ (AIS)], minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IAC). Four different models [EfficientNet-b0 2D, dual-head ResNet_3D, a 3D model combining three features (3D_3F), and a 3D model combining 19 features (3D_19F)] were constructed to evaluate the invasiveness of pGGNs using the EfficientNet and ResNet networks. The Obuchowski index was used to evaluate the differences in diagnostic efficiency among the four models.ResultsThe patients with pGGNs (360 men, 776 women; mean age, 54.63 ± 12.36 years) included 235 cases of AAH + AIS, 332 cases of MIA, and 569 cases of IAC. In the validation group, the areas under the curve in detecting the invasiveness of pGGNs as a three-category classification (AAH + AIS, MIA, IAC) were 0.8008, 0.8090, 0.8165, and 0.8158 for EfficientNet-b0 2D, dual-head ResNet_3D, 3D_3F, and 3D_19F, respectively, whereas the accuracies were 0.6422, 0.6158, 0.651, and 0.6364, respectively. The Obuchowski index revealed no significant differences in the diagnostic performance of the four models.ConclusionsThe dual-head ResNet_3D_3F model had the highest diagnostic efficiency for evaluating the invasiveness of pGGNs in the four models.

The differential diagnosis of lung precursor glandular lesions, micro-invasive adenocarcinoma, and invasive adenocarcinoma using low dose spectral computed tomography perfusion imaging.

Few studies about the association between computed tomography (CT) perfusion imaging parameters and invasiveness in lung adenocarcinoma (LUAD) have been conducted using low dose spectral CT perfusion imaging. The purpose of this study was to investigate application of spectral revolution CT low-dose perfusion imaging in the differential diagnosis of different pathological subtypes of LUAD. This was a cross-sectional study based on historical data from January 2018 to May 2019 in Peking University Cancer Hospital & Institute. A total of 62 cases were enrolled, including 2 cases of atypical adenomatous hyperplasia (AAH), 3 cases of adenocarcinoma in situ (AIS), 4 cases of minimally invasive adenocarcinoma (MIA), and 53 cases of invasive adenocarcinoma (IAC), all confirmed with pathology. The inclusion and exclusion criteria were regulated. Using Revolution low-dose CT perfusion imaging (GE, USA), the CT perfusion parameters of hemodynamics were obtained: blood flow (BF), blood volume (BV), impulse residue function time of arrival (IRF TO), maximum slope of increase (MSI), mean transit time (MTT), permeability surface area product (PS), positive enhancement integral (PEI), and maximum enhancement time (Tmax). Univariate analysis of variance (ANOVA) or Kruskal-Wallis test was used to compare the differences of CT perfusion quantitative parameters among AAH, AIS, MIA, and IAC. Mann-Whitney test was used to compare the difference of CT perfusion imaging parameters between preinvasive lesions (AAH and AIS) and invasive lung cancer (MIA and IAC). Statistically significant differences in IRF TO were observed in LUAD with different invasiveness, namely, among AIS, MIA, and IAC groups (0.56±0.74 vs. 0.54±1.08 vs. 4.39±2.19, P=0.004). Statistically significant differences in IRF TO were also observed between pre-invasive lesions group (AAH and AIS) and invasive lung cancer group (MIA and IAC) (1.12±1.27 vs. 3.75±2.79, P=0.031), and between AAH + AIS + MIA groups and IAC group (0.83±1.13 vs. 4.12±2.69, P<0.001). There were no statistically significant differences in other CT perfusion parameters of hemodynamics among different pathological subtypes of LUAD (P>0.05). The low-dose perfusion parameter IRF TO of revolution CT has the potential to be employed in the differential diagnosis of different pathological subtypes of LUAD.

Growth Regularity of Pulmonary Ground Glass Nodules Based on 3D Reconstruction Technology

Since the popularization of computed tomography (CT) technology, the detection rate of pulmonary ground glass nodules (GGNs) with imaging follow-up as the main management method has increased significantly. The purpose of this study is to quantitatively analyze the changes of pulmonary GGNs during the follow-up process with three-dimensional reconstruction technology, explore the natural progression of pulmonary GGNs, and provide effective basis for clinical guidance for patients to conduct reasonable management of nodules. A total of 115 cases of pulmonary GGNs with regular follow-up in the Combined Outpatient Department of Zhoushan Hospital from March 2015 to November 2022 were enrolled. Quantitative imaging features of nodules were extracted by semi-automatic segmentation of 3D Slicer software to evaluate the growth of nodules and clinical intervention during follow-up. The average baseline age of the patients was (56.9±10.1) yr. The mean follow-up time was (48.8±18.9) months. The two-dimensional diameter of baseline CT scan was (7.9±2.9) mm, and the maximum three-dimensional diameter was (10.1±3.4) mm. The two-dimensional diameter of the last CT scan was (9.9±4.7) mm, and the maximum three-dimensional diameter was (11.4±5.1) mm. A total of 27 cases (23.5%) showed an increase during follow-up, with a median volume doubling time of 822 days and a median mass doubling time of 1,007 days. 32 cases were surgically resected, including 6 cases of invasive adenocarcinoma (IAC), 16 cases of minimally invasive adenocarcinoma (MIA), 8 cases of adenocarcinoma in situ (AIS) and 2 cases of atypical adenomatous hyperplasia (AAH). Five nodules underwent surgical intervention due to the progression of two-dimensional diameter, which was pathologically confirmed as pre-invasive lesions, but their three-dimensional maximum diameter showed no significant change. Nodular morphology, lobulated sign, spiculated sign and vacuole signs all promoted the growth of nodules in univariate analysis. There were significant differences in age, baseline diameter, mean CT value, median CT value, 10% and 90% percentile CT number between the growth group and the stable group (P<0.05). Multivariate Logistic regression analysis showed that age and average CT value were risk factors for nodule growth (P<0.05). Receiver-operating characteristic (ROC) curve analysis results indicated that the age ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU were more likely to accelerate the growth of GGNs. The maximum three-dimensional diameter ≥14.4 mm and the average CT value ≥-495.7 HU may be a higher malignant probability. GGNs show an inert growth process, and the use of three-dimensional measurements during follow-up is of greater significance. For persistent glass grinding nodules ≥63 years old, the baseline three-dimensional maximum diameter ≥9.2 mm, and the average CT value ≥-507.8 HU are more likely to increase. However, most nodules still have good prognosis after progression, and long-term follow-up is safe.

A case of atypical adenomatous hyperplasia incidentally detected in resected specimen of spontaneous pneumothorax in a young adult

A case of atypical adenomatous hyperplasia incidentally detected in resected specimen of spontaneous pneumothorax in a young adult

Three-dimensional reconstruction facilitates thoracoscopic anatomical partial lobectomy by an inexperienced surgeon: a single-institution retrospective review.

BackgroundThis study aimed to evaluate the effect of three-dimensional (3D) interactive quantitative surgical planning on the outcome of video-assisted thoracoscopic surgery (VATS) anatomical partial lobectomy (APL), and to investigate the learning curve of 3D reconstruction-assisted VATS APL assisted.MethodsWe retrospectively analyzed 156 cases of solitary pulmonary ground-glass opacity (GGO) lesions in patients who underwent 3D interactive quantitative VATS APL. Digital imaging and communications in medicine data were recorded for each patient. We used Materialise 3-Matic software to make 3D reconstructed images. All surgeries were performed by the same thoracic surgeon at the Cardiothoracic Surgery Department of Yichang Central People’s Hospital between February 28, 2018, and April 20, 2020. The learning curve was evaluated using operative time and the cumulative sum (CUSUM) value of operative time in all cases.ResultsVATS APL was performed in every patient successfully, and there were no conversions to thoracotomy or lobectomy. The median surgical margin distance was 2.2 (range, 2.0–2.8) cm. All patients had an R0 complete cancer resection on histology. The histological subtypes of the segmental lesions included 69 cases of minimally invasive adenocarcinoma (MIA), 61 cases of adenocarcinoma, one case of squamous cell carcinoma, 16 cases of adenocarcinoma in situ (AIS), and nine cases of atypical adenomatous hyperplasia (AAH). The median operation time was 119 (range, 57–245) min, and median intraoperative blood loss was 37 (range, 15–247) mL. The median duration of thoracic drainage tube insertion was 2.3 (range, 1–23) days after surgery. The median length of postoperative hospital stay was 3.7 (range, 3–25) days. There were no cases of perioperative death. During the median postoperative follow-up period of 11 (range, 2–26) months, no tumor recurrence or postoperative death was observed. 3D interactive quantitative surgical planning facilitates safe and efficient VATS APL with a learning curve of 30 cases.Conclusions3D interactive quantitative surgical planning for VATS APL is a feasible option for inexperienced surgeons, with acceptable safety and complications.

Preoperative non-invasive visual localization of synchronous multiple lung cancers using three-dimensional computed tomography lung reconstruction

BackgroundSynchronous multiple primary lung cancers are becoming more common with increasing use of computed tomography for screening. Intraoperative localization and resection of ill-defined pulmonary ground-glass opacities during thoracoscopic resection is challenging. This study aimed to determine the clinical feasibility of non-invasive visual localization of these nodules by three-dimensional computed tomography lung reconstruction before sublobar resection.MethodsForty-four patients with synchronous multiple primary lung cancers underwent thoracoscopic pulmonary resection at our institution between June 2017 and August 2019. Preadmission computed tomography images were downloaded and reconstructed into a three-dimensional model. Small nodules (< 15 mm) were localized non-invasively by three-dimensional computed tomography lung reconstruction before surgery. Patient demographics, nodule characteristics, procedural details, pathological data, and outcomes were obtained from the medical records.ResultsOne hundred and twenty-one pulmonary nodules from the 44 patients were scheduled for video-assisted thoracic surgery; 54 (44.6%) were pure ground-glass opacities and 57 (47.1%) were mixed ground-glass opacities. One hundred and seventeen nodules were localized preoperatively. The mean nodule diameter was 7.67 ± 3.87 mm. The mean distance from the nodule to the pleura was 14.84 ± 14.43 mm. All nodules were removed successfully by wedge resection (27 patients), lobectomy (26 patients), or segmentectomy (25 patients). Most lesions (85.1%) were malignant. Paraffin pathology revealed 12 cases of atypical adenomatous hyperplasia (9.92%), 13 of adenocarcinoma in situ (10.74%), 16 of minimally invasive adenocarcinoma (13.22%), and 73 of invasive adenocarcinoma (60.33%).ConclusionsThree-dimensional computed tomography lung reconstruction is a feasible and alternative method of visual localization for small lung nodules before sublobar resection in some suitable patients.

Evaluation of the Radiomics Method for the Prediction of Atypical Adenomatous Hyperplasia in Patients With Subcentimeter Pulmonary Ground-Glass Nodules.

ObjectivesWe aimed to develop a prediction model to distinguish atypical adenomatous hyperplasia (AAH) from early lung adenocarcinomas in patients with subcentimeter pulmonary ground-glass nodules (GGNs), which may help avoid aggressive surgical resection for patients with AAH.MethodsSurgically confirmed cases of AAH and lung adenocarcinomas manifesting as GGNs of less than 1 cm were retrospectively collected. A prediction model based on radiomics and clinical features identified from a training set of cases was built to differentiate AAH from lung adenocarcinomas and tested on a validation set.ResultsFour hundred and eighty-five eligible cases were included and randomly assigned to the training (n = 339) or the validation sets (n = 146). The developed radiomics prediction model showed good discrimination performance to distinguish AAH from adenocarcinomas in both the training and the validation sets, with, respectively, 84.1% and 82.2% of accuracy, and AUCs of 0.899 (95% CI: 0.867–0.931) and 0.881 (95% CI: 0.827–0.936).ConclusionThe prediction model based on radiomics and clinical features can help differentiate AAH from adenocarcinomas manifesting as subcentimeter GGNs and may prevent aggressive resection for AAH patients, while reserving this treatment for adenocarcinomas.

Anatomical partial lobectomy for the treatment of 3 336 cases of patients with lung nodule

Objective: To explore the feasibility, safety and effectiveness of anatomical partial lobectomy. Methods: The clinical data of 3 336 patients with lung nodules underwent anatomical partial lobectomy in our center from November 2013 to November 2019 were retrospectively analyzed. We set the safety margin distance according to the imaging feature of the lesion. The surgeons then anatomically detached the major vessels and bronchus in this region, resected the targeted lung tissue along the plane, and completed the resection of anatomical pulmonary lobe and clean and sampling of systemic lymph nodules. Results: A total of 668 cases were multiple nodules and 2 668 cases were solitary pulmonary nodules. According to the postoperative pathological results, 283 cases were benign, 1 197 cases were preinvasive lesions (including 38 cases of atypical adenomatous hyperplasia, 445 cases of adenocarcinoma in situ and 714 cases of minimally invasive adenocarcinoma), 1 713 cases were invasive adenocarcinoma, 73 cases were non-adenocarcinoma and 70 cases were metastatic carcinoma. Among 1 786 invasive primary lung cancers, 11 cases received preoperative neoadjuvant chemotherapy, and their postoperative pathologic diagnoses were stage ypIA. Other 1 775 cases who did not receive postoperative neoadjuvant treatment included 1 587 cases in stage ⅠA, 112 cases in stage ⅠB, 3 cases in stage ⅡA, 18 cases in stage ⅡB, 37 cases in stage ⅢA, 9 cases in stage ⅢB, 9 cases in stage Ⅳ. The average operation time was (127.3±55.3) minutes, and the mean postoperative hospital stay was (4.8±2.4) days. The incidence rate of complications (grade>2) was 1.1%(38/3 336), and no death occurred during 30 days after operation. Conclusion: Anatomic partial lobectomy has good clinical applicability, safety and effectiveness, which is worthy of clinical application and recommendation.

Artificial intelligence-assisted CT characterizations and quantitative analysis for differentiating pre-invasive lesions from invasive adenocarcinomas in pulmonary subsolid nodules ≤ 2cm.

e21614 Background: The use of artificial intelligence (AI) in medical imaging has dramatically improved the quality of segmentation including accuracy, efficiency and reproducibility. This study sought to determine whether AI-assisted computed tomography (CT) features and quantitative analysis of pulmonary subsolid nodules (SSNs) under 2cm could be used to differentiate preinvasive lesions from invasive adenocarcinomas. Methods: Clinical data and CT images of 297 preinvasive lesions and early invasive lung adenocarcinomas confirmed by surgery pathology with CT manifestations of SSNs under 2cm were retrospectively analysed. The nodules were divided into two groups: the preinvasive lesions (PILs, N = 115) including 7 cases of atypical adenomatous hyperplasia (AAH), 30 cases of adenocarcinoma in situ (AIS) and 78 cases of minimally invasive adenocarcinoma (MIA), and the invasive adenocarcinomas (IACs, N = 182). All CTs were processed by AI and the volume, mean CT value, consolidation-to-tumor ratio (CTR), mass and maximum diameter of each SSN were obtained. Results: The volume, mean CT value, CTR, maximum diameter and mass of nodules showed significant difference between the two groups (Table). Multivariate analysis was determined by logistic regression. The regression model between the two groups was logit(p) = -1.439-2.927Volume +0.0005(mean CT value)-0.463(CTR &gt; 0.5) +0.238(maximum diameter)+6.298(mass).The receiver operating characteristic curve (ROC) showed that the mass can do the best prediction among all the independent factors with the areas under the curve(AUC) 0.748 at a cut-off value of 0.154, with the sensitivity of 70.9% and specificity of 70.4% .The AUC of the ROC using the regression probabilities of regression model was 0.769. Conclusions: AI-assisted CT characterizations may be promising tools to predict if SSNs under 2 cm have invaded. [Table: see text]

Correlation between computed tomography imaging and pathological stages and subtypes in early lung adenocarcinoma.

Detection of early-stage lung cancers has increased due to computed tomography (CT). The pathological stages and subtypes of early lung cancer determine the treatment strategy. We aimed to investigate the correlation between CT characteristics and pathological status in early lung adenocarcinoma (ADC). Between June 2018 and December 2019, 415 consecutive patients who underwent surgery for lung ADC with pathological atypical adenomatous hyperplasia (AAH) and ADC in situ (AIS), T1a (mi) N0M0, and T1a-cN0M0 were analyzed. The relationship between CT imaging and pathological status was investigated using Chi-squared or Kruskal-Wallis test and binary logistic regression. When cases of AAH, AIS, and T1a (mi) N0M0 were used as the control group, the lesion size, solid component ratio (SCR), and spiculation were significantly and independently associated with T1a-cN0M0 (P < 0.01). SCR >50% (P < 0.01) and spiculation (P < 0.05) were significantly and independently associated with T1aN0M0. In cases of pathological T1a-cN0M0, SCR >50% was significantly different between adherent wall growth ADC and mucinous ADC (P < 0.01). Some CT characteristics are related to the pathological stage and subtypes of early lung ADC. Larger diameter, spiculation, and SCR >50% are associated with invasive ADC. SCR >50% is positively correlated with mucinous ADC and negatively with adherent growth ADC.

Histomorphological study of prostatic adenocarcinoma and its mimics.

Prostate adenocarcinoma (PC) is one of the common cancers in India and world over. Numerous prostatic, nonprostatic lesions, and normal structures can be very similar to adenocarcinoma. A pathologist's awareness of the benign mimics is important for the diagnosis of PC. The aim of this study was to determine the prevalence, clinical, and histopathological features of PC, and its common mimics, and to study the criteria for their distinction from PC. A prospective study of histopathological features of radical prostatectomy and transurethral resection of the prostate specimens, sent to the department of pathology in a medical college, for a period of 2 years was done. A brief clinical history followed by a clinical examination, including per-rectal findings and serum prostate-specific antigen (PSA) levels, was noted. After excluding all the cases of benign hyperplasia of prostate without any associated findings, 50 cases of operated surgical specimens of prostate were studied. PC was the most frequent diagnosis in 28 patients of 50 cases (56.0%). Basal cell hyperplasia formed the predominant mimic (26.0%), followed by prostatic intraepithelial neoplasia (8%), prostate atrophy (4%), clear-cell cribriform hyperplasia(4%),, and one case of atypical adenomatous hyperplasia (2%). Serum PSA was >4 ng/mL in all the cases of PC. In three of the mimics, PSA was >4 ng/mL and in the rest it was <4 ng/mL. Immunohistochemistry (IHC) was not applied in our study. Biopsy still remains a gold standard for diagnosis of PC and its mimics. All the lesions in the above study were diagnosed on routine hematoxylin and eosin staining. IHC is useful especially for lesions in the grey zone but not in routine histopathological study and should not be used as a screening test but should be applied in specific selected cases only.

How should we manage small focal pure ground-glass opacity nodules on high-resolution computed tomography? A single institute experience

BackgroundAlthough the detection of pure ground-glass opacity (p-GGO) nodules on high-resolution chest computed tomography (HRCT) often implies a diagnosis of lung adenocarcinoma, the management of p-GGO nodules remains under discussion. ObjectiveTo assess the correlation between the radiological and pathological diagnoses of small p-GGO on HRCT. Patients and methodsThis is a single-institution retrospective study. We analyzed 89 consecutive patients, including 33 patients with resected p-GGO nodule(s) equal or less than 20 mm in maximal diameter on axial images of HRCT. ResultsThirty-nine patients underwent locoregional treatment (Treatment group), including surgical resection in 33 and stereotactic body radiation therapy in six. The remaining 50 patients were observed (Observation group) using periodic chest HRCT. The median follow-up time was 30.4 (4.9–102.5) months in the Treatment group and 44.8 (0.4–1125.8) months in the Observation group. During the follow-up period, the p-GGO nodules increased in size in eight patients over a median of 20.6 (12.1–50.6) months, with increased attenuation in three patients over a median of 20.6 (12.1–50.6) months, and either decreased in size or disappeared in four patients over a median of 6.9 (2.0–11.2) months. Thirty-three patients with 47 nodules underwent surgical resection, including 41 adenocarcinomas, one neuroendocrine tumor, three cases of atypical adenomatous hyperplasia and two benign lesions. The frequency of invasive adenocarcinoma was higher among the larger p-GGO nodules. ConclusionsCareful observation and decision making with respect to the timing of intervention in cases of p-GGO nodules are warranted.

The PFA-AMeX method achieves a good balance between the morphology of tissues and the quality of RNA content in DNA microarray analysis with laser-capture microdissection samples.

Recently, large-scale gene expression profiling is often performed using RNA extracted from unfixed frozen or formalin-fixed paraffin embedded (FFPE) samples. However, both types of samples have drawbacks in terms of the morphological preservation and RNA quality. In the present study, we investigated 30 human prostate tissues using the PFA-AMeX method (fixation using paraformaldehyde (PFA) followed by embedding in paraffin by AMeX) with a DNA microarray combined with laser-capture microdissection. Morphologically, in contrast to the case of atypical adenomatous hyperplasia, loss of basal cells in prostate adenocarcinomas was as obvious in PFA-AMeX samples as in FFPE samples. As for quality, the loss of rRNA peaks 18S and 28S on the capillary electropherograms from both FFPE and PFA-AMeX samples showed that the RNA was degraded equally during processing. However, qRT-PCR with 3’ and 5’ primer sets designed against human beta-actin revealed that, although RNA degradation occurred in both methods, it occurred more mildly in the PFA-AMeX samples. In conclusion, the PFA-AMeX method is good with respect to morphology and RNA quality, which makes it a promising tool for DNA microarrays combined with laser-capture microdissection, and if the appropriate RNA quality criteria are used, the capture of credible GeneChip data is well over 80% efficient, at least in human prostate specimens.

Analysis of pre‐invasive lung adenocarcinoma lesions on thin‐section computerized tomography

Recent studies have revealed a potential relationship between the presence of ground glass opacity (GGO) on regular computerized tomography (CT) and adenocarcinomas. To investigate features of pre-invasive lung adenocarcinoma lesions on thin-section CT. We evaluated 59 cases of atypical adenomatous hyperplasia (AAH) and 35 cases of adenoma in situ (AIS) confirmed by histopathology. Comparison of thin-section CT features, such as size, shape, margin, internal characteristics, and adjacent structures of pre-invasive lesions were analyzed. Lesions were further classified to pure ground glass opacity (pGGO) and mixed ground glass opacity (mGGO). Differences were analyzed using Chi-square or Fisher tests. There were significant differences in lobulation, spiculation, and bubble lucency between pGGO and mGGO (P < 0.05), while no differences in air bronchogram, pleural indentation, or vascular morphological changes were identified (P > 0.05). In the group of pGGO, AAH and AIS lesions did not differ significantly in size (P > 0.05), while significant differences were found with respect to lobulation, spiculation, pleural indentation, and vascular morphological changes (P < 0.05). In the group of mGGO, AAH and AIS lesions were significantly different with respect to size (P < 0.05), while no differences were found in lobulation, spiculation, bubble lucency, air bronchogram, or pleural indentation (P > 0.05). Only vascular morphological changes were significantly different between AAH and AIS lesions (P < 0.05). The features of thin-slice CT of AAH and AIS reflected the corresponding morphological changes from AAH progressing to AIS or adenocarcinoma.

Density Features of Screened Lung Tumors in Low-Dose Computed Tomography

Using low-dose computed tomography (LDCT), small and heterogeneous lung tumors are detected in screening. The criteria for assessing detected tumors are crucial for determining follow-up or resection strategies. The purpose of this study was to investigate the capacity of density features in differentiating lung tumors. From July 2008 to December 2011, 48 surgically confirmed tumors (29 malignancies, comprising 17 cases of adenocarcinoma and 12 cases of adenocarcinoma in situ [AdIs], and 19 benignancies, comprising 11 cases of atypical adenomatous hyperplasia [AAH] and eight cases of benign non-AAH) in 38 patients were retrospectively evaluated, indicating that the positive predictive value (PPV) of physicians is 60.4% (29/48). Three types of density features, tumor disappearance rate (TDR), mean, and entropy, were obtained from the CT values of detected tumors. Entropy is capable of differentiating malignancy from benignancy but is limited in differentiating AdIs from benign non-AAH. The combination of entropy and TDR is effective for predicting malignancy with an accuracy of 87.5% (42/48) and a PPV of 89.7% (26/29), improving the PPV of physicians by 29.3%. The combination of entropy and mean adequately clarifies the four pathology groups with an accuracy of 72.9% (35/48). For tumors with a mean below -400 Hounsfield units, the criterion of an entropy larger than 5.4 might be appropriate for diagnosing malignancy. For others, the pathology is either benign non-AAH or adenocarcinoma; adenocarcinoma has a higher entropy than benign non-AAH, with the exception of tuberculoma. Combining density features enables differentiating heterogeneous lung tumors in LDCT.

A Case of Atypical Adenomatous Hyperplasia of Larger Than 2 cm

Atypical adenomatous hyperplasia (AAH) has been considered to be a precursor lesion of bronchioloalveolar carcinoma (BAC) and pulmonary adenocarcinoma. It usually coexists with BAC and/or an adenocarcinoma. Chest computed tomography reveals multiple well-defined nodules with ground-glass opacity. Usually, AAH does not exceed 10 mm in size. AAH with extensive involvement on one side of the lung field or one that is larger than 2 cm has not been previously reported. We herein report a case of a 71-year-old nonsmoking female with lung AAH of larger than 2 cm.

Molecular Alterations in Atypical Adenomatous Hyperplasia Occurring in Benign and Cancer-bearing Lungs

Atypical adenomatous hyperplasia (AAH) is considered to be a precursor lesion of the lung adenocarcinoma. Several genetic abnormalities have been reported in AAH associated with adenocarcinoma, but little is known about AAH associated with benign lung lesions. To address this we compared the molecular characteristics of AAH present in benign conditions to those coexisting with carcinoma. Seven cases of AAH from resected non-neoplastic lungs (AAH-B) and 12 cases from lungs resected for primary lung carcinoma (AAH-M) were analyzed for loss of heterozygosity (LOH) using 21 polymorphic microsatellite markers situated in proximity to known tumor suppressor genes on chromosomes 3p, 5q, 7p, 9p, 10q, and 17p. Direct DNA sequencing for K-ras mutation was also performed. There was a broad range of LOH in both groups. No LOH was identified in 3 cases (25%) of AAH-M, but all cases of AAH-B showed LOH (P=0.26). Six cases (50%) of AAH-M and 3 cases (43%) of AAH-B showed loss at 1 marker (P=0.99). LOH at 2 or more markers was identified in 3 (25%) cases of AAH-M and 4 (57%) cases of AAH-B (P=0.32). LOH was most frequently detected on chromosomes 3p and 10q in both groups. The difference in overall fractional allelic loss between the 2 groups did not reach statistical significance. K-ras mutations were not identified in either group. Our results showed a significant overlap in LOH patterns between AAH with or without coexistent lung malignancy. Therefore, AAH may represent a smoking induced low-grade neoplastic lesion that may be a precursor lesion of only a subset of invasive lung adenocarcinoma.

Atypical adenomatous hyperplasia of lung: clinicopathologic study of 8 cases and review of literature

To study the clinicopathologic and immunohistochemical features of atypical adenomatous hyperplasia (AAH) of lung. Eight cases of AAH of lung were studied by light microscopy and immunohistochemical staining for p16, thyroid transcription factor-1 (TTF-1), Ki-67, p53, epidermal growth factor receptor (EGFR) and c-erbB-2. The mean age of the patients was 52 years. The male-to-female ratio was 1:3. Two patients were chronic smokers. The clinical symptoms were relatively non-specific. Three patients had past history of non-pulmonary tumors, while 4 patients had lung adenocarcinoma. CT scan revealed solitary or multifocal hyperdense opacities. Histologically, the lesions ranged from 1 mm to 6 mm in size. Two cases were solitary and 6 cases were multifocal. All were of high-grade lesions. Associated low-grade component was noted in 3 cases. There was no evidence of local recurrence or disease progression in the 7 patients with post-operative follow-up information available (mean duration of follow up = 23 months). Four patients had received chemotherapy as well. Immunohistochemical study showed variable positivity for p16 (5/8), TTF-1 (5/8), Ki-67 (with proliferation index ranging from 1% to 10%), p53 (1/8) and EGFR (1/8). The staining for c-erbB-2 was negative (0/8). Four cases of AAH were associated with pulmonary adenocarcinoma. The adenocarcinoma cells were diffusely positive for TTF-1 (4/4), variably positive for p16 (2/4), Ki-67 (with proliferation index ranging from 2% to 40%), p53 (1/4) and EGFR (3/4), and negative for c-erbB-2 (0/4). AAH of lung is associated with pulmonary adenocarcinoma. Diagnosis of AAH requires correlation with CT findings and pathologic examination.

Multiple Lung Adenocarcinomas Showing Ground-Glass Opacities on Thoracic Computed Tomography

It is difficult to distinguish multiple primary lung cancers from pulmonary metastasis. We experienced a case of surgically resected lung tumors that showed multiple ground-glass opacities on thoracic computed tomographic scan. There were eight nonsolid and two part-solid ground-glass opacities in the bilateral lungs. Surgical resection was performed because all tumors had a ground-glass opacity appearance on computed tomographic scan, which is compatible with a finding of primary lung adenocarcinoma. The postoperative pathologic diagnoses were two cases of invasive adenocarcinoma, six cases of bronchioloalveolar carcinoma, and eight cases of atypical adenomatous hyperplasia. The patient remains alive without any evidence of recurrence 40 months after surgery. A ground-glass opacity appearance on computed tomographic scan could be interpreted as supportive evidence for multiple primary lung adenocarcinoma rather than pulmonary metastases.