Lung cancer associated with cystic airspaces

Large cell carcinoma of the lung: LDCT features and survival in screen-detected cases

PURPOSE

To investigate the early radiological features and survival of Large Cell Carcinoma (LCC) cases diagnosed in low-dose computed tomography (LDCT) screening trials.

METHODS

Two radiologists jointly reviewed the radiological features of screen-detected LCCs observed in NLST, ITALUNG, and LUSI trials between 2002 and 2016, comprising a total of 29,744 subjects who underwent 3-5 annual screening LDCT examinations. Survival or causes of death were established according to the mortality registries extending more than 12 years since randomization.

RESULTS

LCC was diagnosed in 30 (4 %) of 750 subjects with screen-detected lung cancer (LC), including 15 prevalent and 15 incident cases. Three additional LCCs occurred as interval cancers during the screening period. LDCT images were available for 29 cases of screen-detected LCCs, and 28 showed a single, peripheral, and well-defined solid nodule or mass with regularly smooth (39 %), lobulated (43 %), or spiculated (18 %) margins. One case presented as hilar mass. In 9 incident LCCs, smaller solid nodules were identified in prior LDCT examinations, allowing us to calculate a mean Volume Doubling Time (VDT) of 98.7 ± 47.8 days. The overall five-year survival rate was 50 %, with a significant (p = 0.0001) difference between stages I-II (75 % alive) and stages III-IV (10 % alive).

CONCLUSIONS

LCC is a fast-growing neoplasm that can escape detection by annual LDCT screening. LCC typically presents as a single solid peripheral nodule or mass, often with lobulated margins, and exhibits a short VDT. The 5-year survival reflects the stage at diagnosis.

The Azygos Esophageal Recess Is Not to Be Missed in Screening Lung Cancer With LDCT

PURPOSE

Lesion overlooking and late diagnostic workup can compromise the efficacy of low-dose CT (LDCT) screening of lung cancer (LC), implying more advanced and less curable disease stages. We hypothesized that the azygos esophageal recess (AER) of the right lower lobe (RLL) might be an area prone to lesion overlooking in LC screening.

MATERIALS AND METHODS

Two radiologists reviewed the LDCT examinations of all the screen-detected incident LCs observed in the active arm of 2 randomized clinical trials: ITALUNG and national lung screening trial. Those in the AER were compared with those in the remainder of the RLL for possible differences in diagnostic lag according to the Lung-RADS 1.1 recommendations, size, stage, and mortality.

RESULTS

Six (11.7%) of 51 screen-detected incident LCs of the RLL were located in the AER. The diagnostic lag time was significantly longer (P=0.046) in the AER LC (mean 14±9 mo) than in the LC in the remaining RLL (mean 7.3±1 mo). Size and stage at diagnosis were not significantly different. All 6 subjects with LC in the AER and 16 (35.5%) of 45 subjects with LC in the remaining RLL (P=0.004) died of LC after a median follow-up of 12 years.

CONCLUSION

Our retrospective study indicates that AER might represent a lung region of the RLL prone to have early LC overlooked due to detection or interpretation errors with possible detrimental consequences for the subject undergoing LC screening.

Wolf in sheep's clothing: a case of primary lung adenosquamous carcinoma mimicking traumatic pulmonary pseudocyst

BACKGROUND

Traumatic pulmonary pseudocyst is a rare "cystlike" lung lesion that typically develops following blunt chest trauma. It differs from lung cancer associated with cystic airspaces in terms of pathogenic mechanisms, clinical manifestations, and radiological features. Furthermore, there are few reports of the diagnostic bias between traumatic pulmonary pseudocyst and lung cancer associated with cystic airspaces. Here, we present a rare case of lung cancer associated with cystic airspaces that mimicks traumatic pulmonary pseudocyst.

CASE PRESENTATION

A 61-year-old man with no chest medical or surgical history, no chest radiologic examination within the last five years, and no smoking history had an air-filled "cystlike" lesion surrounded by solid components and ground-glass opacities in the middle third of the right upper lobe of the lung during a computed tomography evaluation following blunt chest trauma. He was initially diagnosed with traumatic pulmonary pseudocyst and treated conservatively. On the third post-trauma day, he experienced hemoptysis, which was successfully treated with intravenous hemostatic medication. On the ninth post-trauma day, he exhibited a significant hemoptysis and a moderate dyspnea. A subsequent chest computed tomography scan demonstrated that the solid components had entered the lesion's cavity and significantly expanded, and the surrounding ground-glass opacities had slightly enlarged. A contrast-enhanced chest computed tomography scan and a three-dimensional reconstruction computed tomography image confirmed that the solid components were a hematoma caused by damage to the right upper pulmonary vein. A right upper lobectomy was performed based on the concern about severe intrapulmonary bleeding. An intraoperative frozen section analysis showed significant bleeding in the lung parenchyma. Adenosquamous carcinoma was unexpectedly identified during the postoperative pathological examination of the resected specimen. A diagnosis of primary lung adenosquamous carcinoma was made. He was discharged on the seventh postoperative day and followed up for two years without any recurrence.

CONCLUSIONS

The potential of lung cancer associated with cystic airspaces should be considered for "cystlike" lung lesions discovered in elderly patients after blunt chest trauma. A comprehensive review of the medical history, meticulous analysis of the radiological findings, and close monitoring can help clinicians reduce the risk of diagnostic bias.

Diagnosis of contralateral rare pulmonary cavity metastasis after lung squamous cell carcinoma surgery by electromagnetic navigation: one case report and review of the literature

Background

Lung cancer associated with cystic airspaces is a rare disease, and a rare imaging performance of non-small cell lung cancer. Due to the lack of conventional diagnosis methods, it is difficult to rely on imaging diagnosis. Therefore, the definitive diagnosis of these neoplastic lesions remains challenging.

Case presentation

We summarize the follow-up and diagnosis of a rare cystic airspaces lung metastatic carcinoma in an elderly man with annular density shadow in the right inferior lobe 2 years after surgery for squamous cell carcinoma in the left inferior lobe.

Results

During the follow-up of the patient, after the lesion of the lower lobe of the right lung was enlarged, the structural and imaging characteristics were identified, and a special method was selected, namely biopsy of the lesion under the electromagnetic navigation bronchoscope, for clear diagnosis and subsequent treatment.

Conclusion

For pulmonary cystic airspaces, it is important to correctly identify their imaging features. Because of the possibility of malignancy, it is essential to stop the radiological study in time and to acquire the pathological diagnosis by an appropriate method.

The impact of cystic lesions on the postoperative prognosis of non-small cell lung cancer: a comparative study

AIM

Due to the rarity of lung cancer with cystic imaging manifestations, we explore the clinical features and survival prognosis of such tumors.

MATERIALS AND METHODS

Imaging characteristics were used to categorize 3,556 patients who underwent surgery for isolated primary lung cancer into one of three groups: those with cystic lung cancer (149), solid lung cancer (1,399), and ground-glass lung cancer (1,160). Propensity score matching by sex and age was performed to analyze the differences in clinical characteristics of lung cancer among the three groups and the correlation between clinical characteristics of cystic lesions and progression-free survival (PFS).

RESULTS

The three groups of patients differed in various aspects, including pathological type, smoking history, tumor stage, type of surgery, histological grading, and PFS (P < 0.05). The results of the multifactorial analysis indicated that lung cancer type, pathological type, lymph node metastasis, tumor stage, and histologic grading were independent prognostic factors for lung cancer (P < 0.05). After comparison, there was a difference in prognosis between cystic lung cancer and ground-glass lung cancer (P < 0.05).

CONCLUSION

The clinical features of cystic lung cancer are significantly different from those of ground-glass lung cancer and solid lung cancer. Cystic lesions are independent influencing factors affecting lung cancer, and the prognosis of cystic lung cancer is worse than that of ground-glass lung cancer.

A nomogram combining CT-based radiomic features with clinical features for the differentiation of benign and malignant cystic pulmonary nodules

BACKGROUND

Currently, the differentiation between benign and malignant cystic pulmonary nodules poses a significant challenge for clinicians. The objective of this retrospective study was to construct a predictive model for determining the likelihood of malignancy in patients with cystic pulmonary nodules.

METHODS

The current study involved 129 patients diagnosed with cystic pulmonary nodules between January 2017 and June 2023 at the Neijiang First People's Hospital. The study gathered the clinical data, preoperative imaging features of chest CT, and postoperative histopathological results for both cohorts. Univariate and multivariate logistic regression analyses were employed to identify independent risk factors, from which a prediction model and nomogram were developed. In addition, The model's performance was assessed through receiver operating characteristic (ROC) curve analysis, calibration curve analysis, and decision curve analysis (DCA).

RESULTS

A cohort of 129 patients presenting with cystic pulmonary nodules, consisting of 92 malignant and 37 benign lesions, was examined. Logistic data analysis identified a cystic airspace with a mural nodule, spiculation, mural morphology, and the number of cystic cavities as significant independent predictors for discriminating between benign and malignant cystic lung nodules. The nomogram prediction model demonstrated a high level of predictive accuracy, as evidenced by an area under the ROC curve (AUC) of 0.874 (95% CI: 0.804-0.944). Furthermore, the calibration curve of the model displayed satisfactory calibration. DCA proved that the prediction model was useful for clinical application.

CONCLUSION

In summary, the risk prediction model for benign and malignant cystic pulmonary nodules has the potential to assist clinicians in the diagnosis of such nodules and enhance clinical decision-making processes.

Incidental pulmonary nodules - current guidelines and management

BACKGROUND

 Due to the greater use of high-resolution cross-sectional imaging, the number of incidental pulmonary nodules detected each year is increasing. Although the vast majority of incidental pulmonary nodules are benign, many early lung carcinomas could be diagnosed with consistent follow-up. However, for a variety of reasons, the existing recommendations are often not implemented correctly. Therefore, potential for improvement with respect to competence, communication, structure, and process is described.

METHODS

 This article presents the recommendations for incidental pulmonary nodules from the current S3 guideline for lung cancer (July 2023). The internationally established recommendations (BTS guidelines and Fleischner criteria) are compared and further studies on optimized management were included after a systematic literature search in PubMed.

RESULTS AND CONCLUSION

 In particular, AI-based software solutions are promising, as they can be used in a support capacity on several levels at once and can lead to simpler and more automated management. However, to be applicable in routine clinical practice, software must fit well into the radiology workflow and be integrated. In addition, "Lung Nodule Management" programs or clinics that follow a high-quality procedure for patients with incidental lung nodules or nodules detected by screening have been established in the USA. Similar structures might also be implemented in Germany in a future screening program in which patients with incidental pulmonary nodules could be included.

KEY POINTS

  · Incidental pulmonary nodules are common but are often not adequately managed. · The updated S3 guideline for lung cancer now includes recommendations for incidental pulmonary nodules. · Competence, communication, structure, and process levels offer significant potential for improvement.

CITATION FORMAT

· Glandorf J, Vogel-Claussen J, . Incidental pulmonary nodules - current guidelines and management. Fortschr Röntgenstr 2024; 196: 582 - 590.

Exploring the molecular and immune-landscape of lung cancer associated with cystic airspaces

To explore the molecular biological characteristics of lung cancer associated with cystic airspaces (LCCA) and its potential roles on prognosis. A total of 165 LCCAs and 201 non-LCCAs were enrolled in this study. Bulk RNA sequencing was implemented in eight LCCAs and nine non-LCCAs to explore the differentially expressed genes. TCGA data were used to analyze LCCA-specific genes that associated with overall survival (OS). The median age was 60 (IQR 53 to 65) years in LCCA cohort. We found LCCA were predominant in men and had less visceral pleura invasion (VPI) or lympho-vascular invasion (LVI). Moreover, LCCA presented with higher histological heterogeneity. Kaplan-Meier analysis showed that patients of age more than 60 and positive VPI had significantly less PFS in LCCA. Cox regression suggested that LCCA, micropapillary subtype proportion and VPI were the independent risk factors for PFS. LCCA had up-regulated pathways associated with EMT, angiogenesis and cell migration. In addition, LCCA displayed higher levels of immunosuppressor infiltration (M2 macrophages, CAFs and MDSCs) and distinct cell death and metabolic patterns. BCR/TCR repertoire analysis revealed less BCR richness, clonality and high-abundance shared clonotypes in LCCA. Finally, Cox regression analysis identified that four cystic-specific genes, KCNK3, NRN1, PARVB and TRHDE-AS1, were associated with OS of lung adenocarcinoma (LUAD). And cystic-specific risk scores (CSRSs) were calculated to construct a nomogram, which performance well. Our study for the first time indicated significantly distinct molecular biological and immune characteristics between LCCA and non-LCCA, which provide complementary prognostic values in early-stage non-small cell lung cancer (NSCLC).

A case of pulmonary pleomorphic carcinoma associated with cystic airspace

Lung cancer associated with a cystic airspace is frequently misdiagnosed or overlooked. Adenocarcinoma, followed by squamous cell carcinoma, is the most typical histologic type of lung cancer connected to a cystic airspace. Here we present the rare case of lung pleomorphic carcinoma associated with a cystic airspace. We encountered a 74-year-old Japanese man diagnosed by computed tomography (CT) as having a nodule outside a cystic airspace in the lung. Several previous CT images showed that the cystic airspace preceded the nodule. Postsurgery, pathology indicated a diagnosis of pleomorphic carcinoma. Since pulmonary pleomorphic carcinomas pursue an aggressive clinical course, their early detection may contribute to an improved prognosis. Our case demonstrated that pleomorphic carcinoma can arise with cystic airspaces. For early diagnosis of those aggressive lung cancers, chest physicians should carefully examine the walls of cystic airspaces on CT.

Lung Cancer Screening with Low-Dose CT: What We Have Learned in Two Decades of ITALUNG and What Is Yet to Be Addressed

The ITALUNG trial started in 2004 and compared lung cancer (LC) and other-causes mortality in 55-69 years-aged smokers and ex-smokers who were randomized to four annual chest low-dose CT (LDCT) or usual care. ITALUNG showed a lower LC and cardiovascular mortality in the screened subjects after 13 years of follow-up, especially in women, and produced many ancillary studies. They included recruitment results of a population-based mimicking approach, development of software for computer-aided diagnosis (CAD) and lung nodules volumetry, LDCT assessment of pulmonary emphysema and coronary artery calcifications (CAC) and their relevance to long-term mortality, results of a smoking-cessation intervention, assessment of the radiations dose associated with screening LDCT, and the results of biomarkers assays. Moreover, ITALUNG data indicated that screen-detected LCs are mostly already present at baseline LDCT, can present as lung cancer associated with cystic airspaces, and can be multiple. However, several issues of LC screening are still unaddressed. They include the annual vs. biennial pace of LDCT, choice between opportunistic or population-based recruitment. and between uni or multi-centre screening, implementation of CAD-assisted reading, containment of false positive and negative LDCT results, incorporation of emphysema. and CAC quantification in models of personalized LC and mortality risk, validation of ultra-LDCT acquisitions, optimization of the smoking-cessation intervention. and prospective validation of the biomarkers.

Lung adenocarcinoma associated with cystic airspaces: Predictive value of CT features in assessing pathologic invasiveness

OBJECTIVES

Lung adenocarcinoma associated with cystic airspaces (LACA) is a unique entity with limited understanding. Our aim was to evaluate the radiological characteristics of LACA and to study which criteria were predictive of invasiveness.

METHODS

A retrospective monocentric analysis of consecutive patients with pathologically confirmed LACA was performed. The diagnosed adenocarcinomas were classified into preinvasive (atypical adenomatous hyperplasia, adenocarcinoma in situ, or minimally invasive adenocarcinoma) and invasive adenocarcinomas. Eight clinical features and twelve CT features were evaluated. Univariable and multivariable analyses were performed to analyse the correlation between invasiveness, and CT and clinical features. The inter-observer agreement was evaluated using κ statistics and intraclass correlation coefficients. The predictive performance of the model was evaluated using the area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 252 patients with 265 lesions (128 men and 124 women; mean age, 58.0 ± 11.1 years) were enrolled. Multivariable logistic regression indicated that multiple cystic airspaces (OR, 5.599; 95 % CI, 1.865-16.802), irregular shape of cystic airspace (OR, 3.236; 95 % CI, 1.073-9.761), entire tumour size (OR, 1.281; 95 % CI, 1.075-1.526), and attenuation (OR, 1.007; 95 % CI, 1.005-1.010) were independent risk factors for invasive LACA. The AUC of the logistic regression model was 0.964 (95 % CI, 0.944-0.985).

CONCLUSION

Multiple cystic airspaces, irregular shape of cystic airspace, entire tumour size, and attenuation were identified as independent risk factors for invasive LACA. The prediction model gives a good predictive performance, providing additional diagnostic information.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

Thin-slice computed tomography enables to classify pulmonary subsolid nodules into pre-invasive lesion/minimally invasive adenocarcinoma and invasive adenocarcinoma: a retrospective study

The aim was to investigate the ability of thin-slice computed tomography (TSCT) to differentiate invasive pulmonary adenocarcinomas (IACs) from pre-invasive/minimally invasive adenocarcinoma (AAH-MIAs), manifesting as subsolid nodules (SSNs) of diameter less than 30 mm. The CT findings of 810 patients with single subsolid nodules diagnosed by pathology of resection specimens were analyzed (atypical adenomatous hyperplasia, n = 13; adenocarcinoma in situ, n = 175; minimally invasive adenocarcinoma, n = 285; and invasive adenocarcinoma, n = 337). According to the classification of lung adenocarcinoma published by WHO classification of thoracic tumors in 2015, TSCT features of 368 pure ground-glass nodules (pGGN) and 442 part-solid nodules (PSNs) were compared AAH-MIAs with IACs. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed. In pGGNs, multivariate analysis of factors found to be significant by univariate analysis revealed that higher mean-CT values (p = 0.006, OR 1.006, 95% CI 1.002-1.010), larger tumor size (p < 0.001, OR 1.483, 95% CI 1.304-1.688) with air bronchogram and non-smooth margins were significantly associated with IACs. The optimal cut-off tumor diameter for AAH-MIAs lesions was less than 10.75 mm (sensitivity, 82.8%; specificity, 80.6%) and optimal cut-off mean-CT value - 629HU (sensitivity, 78.1%; specificity, 50.7%). In PSNs, multivariate analysis of factors found to be significant by univariate analysis revealed that smaller tumor diameter (p < 0.001, OR 0.647, 95% CI 0.481-0.871), smaller size of solid component (p = 0.001, OR 83.175, 95% CI 16.748-413.079),and lower mean-CT value of solid component (p < 0.001, OR 1.009, 95% CI 1.004-1.014) were significantly associated with AAH-MIAs (p < 0.05). The optimal cut-off tumor diameter, size of solid component, and mean-CT value of solid component for AAH-MIAs lesions were less than 14.595 mm (sensitivity, 71.1%; specificity, 83.4%), 4.995 mm (sensitivity, 97.8%; specificity, 92.3%) and - 227HU (sensitivity, 65.6%; specificity, 76.3%), respectively. In subsolid nodules, whether pGGN or PSNs, the characteristics of TSCT can help in distinguishing IACs from AAH-MIAs.

Lung squamous cell carcinoma presenting as rare clustered cystic lesions: A case report and review of literature

BACKGROUND

Lung cancer is the leading cause of cancer-related death. Early diagnosis is critical to improving a patient’s chance of survival. However, lung cancer associated with cystic airspaces is often misdiagnosed or underdiagnosed due to the absence of clinical symptoms, poor imaging specificity, and high risk of biopsy-related complications.

CASE SUMMARY

We report an unusual case of cancer in a 55-year-old man, in which the lesion evolved from a small solitary thin-walled cyst to lung squamous cell carcinoma (SCC) with metastases in both lungs. The SCC manifested as rare clustered cystic lesions, detected on chest computed tomography. There were air-fluid levels, compartments, and bronchial arteries in the cystic lesions. Additionally, there was no clear extrathoracic metastasis. After chemotherapy, the patient achieved a partial response, type I respiratory failure was relieved, and the lung lesions became a clustered thin-walled cyst.

CONCLUSION

Pulmonary cystic lesions require regular imaging follow-up. Lung SCC should be a diagnostic consideration in cases of thin-walled cysts as well as multiple clustered cystic lesions.

Single CT Appointment for Double Lung and Colorectal Cancer Screening: Is the Time Ripe?

Annual screening of lung cancer (LC) with chest low-dose computed tomography (CT) and screening of colorectal cancer (CRC) with CT colonography every 5 years are recommended by the United States Prevention Service Task Force. We review epidemiological and pathological data on LC and CRC, and the features of screening chest low-dose CT and CT colonography comprising execution, reading, radiation exposure and harm, and the cost effectiveness of the two CT screening interventions. The possibility of combining chest low-dose CT and CT colonography examinations for double LC and CRC screening in a single CT appointment is then addressed. We demonstrate how this approach appears feasible and is already reasonable as an opportunistic screening intervention in 50–75-year-old subjects with smoking history and average CRC risk. In addition to the crucial role Computer Assisted Diagnosis systems play in decreasing the test reading times and the need to educate radiologists in screening chest LDCT and CT colonography, in view of a single CT appointment for double screening, the following uncertainties need to be solved: (1) the schedule of the screening CT; (2) the effectiveness of iterative reconstruction and deep learning algorithms affording an ultra-low-dose CT acquisition technique and (3) management of incidental findings. Resolving these issues will imply new cost-effectiveness analyses for LC screening with chest low dose CT and for CRC screening with CT colonography and, especially, for the double LC and CRC screening with a single-appointment CT.

Case Report: Misdiagnosis of Lung Carcinoma in Patients with Shrunken Lung Cyst After High Altitude Travel

Background

Lung cancer associated with cystic airspace is a rare disease, and the imaging understanding of lung cancer with cystic cavity is still unclear. Little is known in the literature on whether cystic lung cancer is caused by emphysema or ruptured bullae.

Case Reports

We report the case of a 50-year-old female patient after finishing a business trip in November 2021, when another chest CT demonstrated an unexpected reduction in the cyst, with a solid mural nodule on the posterior wall. The airspace of the cyst is only about 13 mm × 12 mm × 6 mm in size. The size of the mural nodule in the posterior wall is about 10 mm × 6 mm × 5 mm. The patient felt anxious due to suspicion of lung cancer. 2.5 months after the last chest CT, she accepted minimally invasive thoracoscopic surgery on the posterior basal segment of the left lower lobe. The postoperative pathology showed benign lesions.

Conclusion

For radiologists, it is important to recognize the process from lung cysts or bullae to LC-CAS, especially the morphological changes of the cyst airspace and the cyst wall, in order to identify the malignant features of lung cysts in time.

Pulmonary carcinoma associated with cystic airspaces in two dogs

Malignant pulmonary neoplasia associated with cystic airspaces is a well-recognised disease entity in humans. Two elderly dogs, previously diagnosed with a solitary emphysematous bulla, presented with non-specific clinical signs. At presentation, pulmonary auscultation was unremarkable. In both cases, thoracic CT demonstrated the transformation of the cystic airspace lesions characterised by a progressive increase of the solid component and reduction of the air component. Cytological evaluation and subsequent surgical excision followed by histopathology confirmed pulmonary carcinoma in both cases. These two cases represent the first demonstration of possible malignant transformation of pulmonary cystic airspace in dogs. Veterinarians should consider neoplastic transformation as a differential diagnosis in cases of cystic airspaces, particularly cases with features including thickening or irregularity of the wall, associated soft-tissue nodules or solid and non-solid tissue intermixed within clusters of multiple cystic airspaces. Ongoing monitoring of cystic airspace lesions through diagnostic imaging is recommended.

Pearls and Pitfalls in Lung Cancer Imaging

Imaging plays an essential role in the diagnosis and staging of pulmonary malignancy. Familiarity of less common manifestations of lung cancer including subsolid nodule, consolidation, and cyst associated lung cancer is important to avoid delayed diagnosis and improve patient outcomes. In this article, we review the staging of multifocal lung cancer, PET negative lung cancers (carcinoid and indolent lung adenocarcinoma), and false positive lymph nodes on PET due to infectious and inflammatory etiologies. Knowledge of these potential pitfalls and pearls in lung cancer imaging and correlation with patients' clinical history are essential to prevent misinterpretation.

Serial CT changes in different components of lung cancer associated with cystic airspace in patients treated with neoadjuvant chemotherapy

The aim of this study was to observe changes in different components (solid, cystic airspace, or entire tumor) in lung cancer associated with cystic airspace following treatment with neoadjuvant chemotherapy (NC), using computerized tomography (CT). We analyzed serial (baseline, first-time follow-up, and last-time follow-up) clinical data and CT imaging in six patients treated with NC. The diameters, areas, and volumes of different tumor components (solid, cystic airspace, and entire tumor) were measured. Delta (Δ) was used to represent changes in these parameters between two examinations: Δ1(%) represents the change from baseline to first follow-up after NC, and Δ2(%) represents the change from baseline to last follow-up after NC. We used the intra-group correlation coefficient (ICC) to test for consistency between parameters as measured by two radiologists. The diameter of solid components in all lesions showed a trend of continuous reduction compared with baseline (Δ1 ranged from − 8.3 to − 46.0%, Δ2 from − 30.8 to − 69.2%). For cystic airspace and entire tumors, different lesions showed different trends over the course of treatment. For diameter, area, and volume, Δ1 of changes in the solid component ranged from − 8.3 to − 46.9%, − 19.4 to − 70.8%, and − 19.1 to − 94.7%, respectively; Δ2 ranged from − 30.8 to − 69.2%, − 50.8 to − 92.1%, and − 32.7 to − 99.8% in diameter, area, and volume, respectively. Results were inconsistent between different components of lung cancer associated with cystic airspace that was treated with NC, but the diameter, area, and volume of solid components were continuously reduced during treatment. Furthermore, area and volume measurements showed more-significant variation than diameter measurements.

Solitary multicystic lesion lung cancer: two case reports and review of the literature

Background

Lung cancer associated with cystic airspaces, especially solitary multicystic lesion lung cancer, is a rare disease (a rare imaging performance of non-small cell lung cancer). It is difficult to diagnose owing to the lack of a clear definition; therefore, diagnosis of these neoplastic lesions remains challenging.

Case presentation

We outlined two cases of elderly Chinese men who were admitted to the hospital with a solitary multicystic lesion of the lung and subsequent surgical resection, confirming a diagnosis of adenocarcinoma.

Conclusions

For solitary pulmonary cystic airspaces (especially solitary multicystic lung lesions), it is important to properly recognise their imaging features. Due to the possibility of malignancies, timely surgery is an effective treatment strategy for early diagnosis.

Cystic Primary Lung Cancer: Evolution of Computed Tomography Imaging Morphology Over Time

PURPOSE

Primary lung cancers associated with cystic airspaces are increasingly being recognized; however, there is a paucity of data on their natural history. We aimed to evaluate the prevalence, pathologic, and imaging characteristics of cystic lung cancer in a regional thoracic surgery center with a focus on the evolution of computed tomography morphology over time.

MATERIALS AND METHODS

Consecutive patients referred for potential surgical management of primary lung cancer between January 2016 and December 2018 were included. Clinical, imaging, and pathologic data were collected at the time of diagnosis and at the time of the oldest computed tomography showing the target lesion. Descriptive analysis was carried out.

RESULTS

A total of 441 cancers in 431 patients (185 males, 246 females), median age 69.6 years (interquartile range: 62.6 to 75.3 y), were assessed. Overall, 41/441 (9.3%) primary lung cancers were cystic at the time of diagnosis. The remaining showed solid (67%), part-solid (22%), and ground-glass (2%) morphologies. Histopathology of the cystic lung cancers at diagnosis included 31/41 (76%) adenocarcinomas, 8/41 (20%) squamous cell carcinomas, 1/41 (2%) adenosquamous carcinoma, and 1/41 (2%) unspecified non-small cell lung carcinoma. Overall, 8/34 (24%) cystic cancers at the time of diagnosis developed from different morphologic subtype precursor lesions, while 8/34 (24%) cystic precursor lesions also transitioned into part-solid or solid cancers at the time of diagnosis.

CONCLUSIONS

This study demonstrates that cystic airspaces within lung cancers are not uncommon, and may be seen transiently as cancers evolve. Increased awareness of the spectrum of cystic lung cancer morphology is important to improve diagnostic accuracy and lung cancer management.

Prognosis of lung cancer associated with cystic airspaces: A propensity score matching analysis

OBJECTIVE

The association between the morphological characteristics and survival outcome of lung cancer associated with cystic airspaces (LCCAs) is unclear due to rarity of this disease. The current study attempted to compare the survival outcome between LCCAs and non-LCCAs and investigate the correlation between imaging features and prognosis of LCCA.

METHOD

Of 10,835 patients diagnosed with non-small cell lung carcinoma (NSCLC) between January 2015 and December 2016, 123 patients with LCCA were included. The non-LCCA group comprised 3136 patients with primary solitary adenocarcinoma or squamous cell lung cancer. Propensity score matching (PSM) was performed for age, sex, tumor size, tumor stage, and lymph node involvement in a 1:1 ratio between the LCCAs and non-LCCAs, and the correlation between radiological features and recurrence-free survival (RFS) was analyzed.

RESULT

The computed tomography (CT) lesion size was found to be higher in all LCCA subtypes, particularly in Type III (a cystic airspace with a mural nodule) and Type IV (mixed) LCCAs (3.09 and 3.65 cm, respectively), than in non-LCCAs (2 cm) after PSM. Three-year RFS in the LCCA group was higher than in the non-LCCA group (Type I- IV LCCAs: 100%, 84%, 77% and 83%, respectively vs. non-LCCAs: 77%). However, statistically significant difference was only found in comparison between LCCA Type I (thin-walled) and non-LCCA groups (P = 0.026). Type III lung cancer exhibited the worst survival among all four LCCA subtypes.

CONCLUSIONS

The CT lesion size and pathologic tumor size varied significantly across LCCAs. Type I LCCAs exhibited better survival than non-LCCAs, whereas Type III LCCAs exhibited the worst survival rate among the four LCCA subtypes.

Managing Incidental Findings on Thoracic CT: Lung Findings. A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee presents recommendations for managing incidentally detected lung findings on thoracic CT. The Chest Subcommittee is composed of thoracic radiologists who endorsed and developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address commonly encountered incidental findings in the lungs and are not intended to be a comprehensive review of all pulmonary incidental findings. The goal is to improve the quality of care by providing guidance on management of incidentally detected thoracic findings.

Clinical Value and Pathologic Basis of Cystic Airspace Within Subsolid Nodules Confirmed as Lung Adenocarcinomas by Surgery

PURPOSE

To investigate the clinical value and pathologic basis of cystic airspace within lung adenocarcinomas manifesting as subsolid nodules.

PATIENTS AND METHODS

A retrospective study was conducted on a total of 541 surgically confirmed lung adenocarcinomas manifesting as subsolid nodules in computed tomography images, including 87 cases with cystic airspace and 454 cases without cystic airspace. The pathologic characteristics of the cases with and without cystic airspace were compared. The investigation of the pathologic structure of cystic airspace was attempted on the postoperative paraffin sections.

RESULTS

There was a significant difference in the containing of cystic airspace between preinvasive and invasive adenocarcinomas (10.5 vs 26.6%; P < .001). Multivariate analysis indicated that cystic airspace is an independent predictor of invasive adenocarcinomas (odds ratio, 3.220; 95% confidence interval, 1.822-5.687). Nodules containing multiple cystic airspaces are more likely to be invasive adenocarcinomas than nodules with a single cystic airspace (47.1 vs 72.2%; P < .05). On paraffin sections, the walls of the cystic airspace seemed to be mainly composed of atypical hyperplasia and/or tumor cells on the surface and the remaining smooth muscle cells and stroma below, which is similar to the structure of bronchi.

CONCLUSIONS

Cystic airspace may be a reliable predictor of invasive adenocarcinomas, the classification method based on the number of cystic airspaces might be suitable for the computed tomography-based typing of cystic airspace within subsolid nodules. Cystic airspace may derive from the destroyed and enlarged bronchi owing to the growth or infiltration of atypical hyperplasia and/or tumor cells.

Clinicopathologic and Longitudinal Imaging Features of Lung Cancer Associated With Cystic Airspaces: A Systematic Review and Meta-Analysis

BACKGROUND. Lung cancer (LC) associated with cystic airspaces is an uncommon presentation that is underrecognized on imaging. Additionally, understanding of its underlying pathology and risk factors is limited, which can contribute to delays in diagnosis. OBJECTIVE. The purpose of this analysis was to systematically review, analyze, and synthesize the medical literature to determine the imaging features of LC associated with cystic airspaces. EVIDENCE ACQUISITION. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included published research reporting the clinical, pathologic, and imaging features of LC associated with cystic airspaces. We then performed a pooled analysis of continuous and categoric data with respect to patient clinical characteristics, tumor pathologic features, underlying driver mutation, CT features, and evolution of these features over time. EVIDENCE SYNTHESIS. The analysis included eight original observational studies with a combined total of 341 patients with LC associated with cystic airspaces (weighted mean age, 61.8 years; range, 30-87 years; 135 women and 206 men). Most patients were current or previous smokers (127/192 [66.1%]). The most common histologic finding was adenocarcinoma (289/328 [88.1%]) followed by squamous cell carcinoma (30/328 [9.1%]). The most common driver mutations were EGFR (46/122 [37.7%]) and KRAS (21/122 [17.2%]). The cysts in LC associated with cystic airspaces commonly had nonuniform (104/114 [91.2%]) and thick (83/222 [37.4%]) walls, irregular margins (53/142 [37.3%]), and were unilocular (173/272 [63.6%]). Most cysts had a nodular component (210/328 [64.0%]). Over time, most cysts showed development or enlargement of the nodular component (61/89 [68.5%]), approximately half showed wall thickening (43/89 [48.3%]), and a minority evolved into completely solid lesions (11/89 [12.4%]). The size of the cystic component increased in 36 of 89 patients (40.4%), decreased in 28 (31.5%), and remained stable in 24 (27.0%). CONCLUSION. LC associated with cystic airspaces occurs most commonly as adeno-carcinoma and is seen in both smokers and nonsmokers. The cysts associated with LC show wall thickening and mural nodularity, which may evolve over time. LC associated with cystic airspaces can be indolent, and long-term surveillance with imaging should be considered if cysts are not resected. CLINICAL IMPACT. Familiarity with the imaging features and temporal evolution of LC associated with cystic airspaces can minimize delays in LC diagnosis. Future management guidelines should include protocols for follow-up and management of cystic lung lesions identified during diagnostic and LC screening CT.

Evolution of cystic airspaces lung lesions on immune checkpoint inhibition in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) can be associated with pulmonary cystic airspaces (pCAs). pCAs are radiologically classified into four types based on whether the nodule or mass extrudes the wall of the pCAs. In most cases, response evaluation of these lesions by Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1 is challenging. Based on the observation of a case of morphological evolution of pCAs associated with NSCLC in a patient receiving immune checkpoint inhibitor (ICI), we reviewed retrospectively imaging scans of 92 consecutive advanced patients with NSCLC treated at our institution. Overall, three cases of pCAs associated with NSCLC obtained a remarkable change following ICI. Of note, these changes were not always seen in the context of a clear radiological objective response. The morphological changes observed may reflect a novel pattern of response to immunotherapy agents that clinicians should be aware of. This pattern of response, not reported before, warrants further investigation and, if confirmed, we believe that it should be considered in future version of immune RECIST.

Peripheral type squamous cell carcinoma of the lung: clinicopathologic characteristics in comparison to the central type

BACKGROUND

Squamous cell carcinomas (SqCCs) of the lung are known to arise more often in a central area but reports of peripheral SqCCs have increased, with a pathogenesis that is obscured. In this study, the clinicopathologic characteristics of peripheral lung SqCCs were studied and compared with those of the central type.

METHODS

This study included 63 peripheral lung SqCCs and 48 randomly selected central cases; hematoxylin and eosin-stained slides of surgically resected specimens were reviewed in conjunction with radiologic images and clinical history. Cytokeratin-7 immunohistochemical staining of key slides and epidermal growth factor receptor (EGFR)/KRAS mutations tested by DNA sequencing were also included.

RESULTS

Stages of peripheral SqCCs were significantly lower than central SqCCs (p=.016). Cystic change of the mass (p=.007), presence of interstitial fibrosis (p=0.007), and anthracosis (p=.049) in the background lung were significantly associated with the peripheral type. Cytokeratin-7 positivity was also higher in peripheral SqCCs with cutoffs of both 10% and 50% (p=.011). Pathogenic mutations in EGFR and KRAS were observed in only one case out of the 72 evaluated. The Cox proportional hazard model indicated a significantly better disease-free survival (p=.009) and the tendency of better overall survival (p=.106) in the peripheral type.

CONCLUSIONS

In peripheral type, lower stage is a favorable factor for survival but more frequent interstitial fibrosis and older age are unfavorable factors. Multivariate Cox analysis revealed that peripheral type is associated with better disease-free survival. The pathogenesis of peripheral lung SqCCs needs further investigation, together with consideration of the background lung conditions.

Clinicopathological characteristics of solitary cavitary lung cancer: a case-control study

Background

With the emerging radiological techniques and the increasing incidence of adenocarcinoma, the composition and structure of cavitary lung cancer have been significantly changed. The aim of the study was to demonstrate clinicopathological characteristics of solitary cavitary lung cancer which was ≤3 cm.

Methods

A case-control study was designed through retrospective data analysis of clinicopathological data of 946 cases with solitary lung cancer smaller than 3 cm. Univariable and multivariable analysis were used to identify the risk factors of cavitation.

Results

Cavitary lung cancer occurred more frequently in patients who were elderly (P=0.044), male (P=0.004), who had a smoking history (P=0.018), higher carcinoembryonic antigen (CEA) level (P<0.001), peripheral lesions (P=0.017), solid nodules (P<0.001), spiculation (P=0.003), vascular convergence (P<0.001), air bronchogram (P=0.004), larger tumor size (P<0.001), advanced T stage (P<0.001), lymph node metastasis (P=0.028) and advanced pTNM stage (P=0.004). In addition, cavitary lung cancer was more common in papillary predominant tumors (P=0.017), while noncavitary lung cancer occurred more frequently in AIS/MIA (P=0.002) and lepidic predominant tumors (P<0.001). It was confirmed that cavitation was significantly associated with elderly (P=0.013), male (P=0.003), larger maximum tumor diameter (P<0.001), solid nodules (P<0.001), larger pT size (P=0.016) and advanced pN stage (P=0.036) in multivariable analysis. ROC curves showed that the AUV was greater in maximum tumor diameter than in pT size predicting cavitation (0.71 vs. 0.66). A cut off value of 20.9 mm showed a discriminatory power of cavitation with a sensitivity of 68.7% and a specificity of 71.2%.

Conclusions

Comparing with noncavitary lung cancer, cavitary lung cancer smaller than 3 cm may have worse prognostic clinical, radiological and pathological characteristics. Especially, cavitary lung cancer present as more solid nodules on CT images and present with more invasive on pathological findings.

Stepwise Disease Progression Model of Subsolid Lung Adenocarcinoma with Cystic Airspaces

OBJECTIVES

Subsolid lung adenocarcinoma with cystic airspaces (LACA) is a unique manifestation of lung cancer. This study was conducted to establish a radiologic disease progression model of LACA and to explore its association with the clinical course and clinicopathologic features of LACA.

MATERIALS AND METHODS

Sixty patients with LACA who underwent surgery at our center between 2004 and 2017 were retrospectively reviewed. The morphological changes of LACA over time on 98 serial computed tomography scans from 27 of 60 patients were tracked to establish a radiologic disease progression model. Associations between this model and the clinicopathologic characteristics of LACA were investigated.

RESULTS

The following stepwise progression model of LACA was developed: in phase I, cystic airspaces (CAs) appear in the middle of non-solid nodules; in phase II, the CAs grow; in phase III, a solid component appears on the border of the CAs; and in phase IV, the solid component gradually surrounds the CAs and becomes thicker, and the CAs shrink. In total, 10 (17%), 33 (55%), and 17 (28%) LACA patients were classified as belonging to phases II, III, and IV at the time of surgery, respectively. More advanced phases were associated with higher pathologic T and N staging, lymphovascular invasion, visceral pleural invasion, spread through air spaces, and solid/micropapillary subtype. In the multivariate analysis, our model demonstrated a good discrimination capability for cancer recurrence risk.

CONCLUSIONS

The stepwise disease progression model of LACA based on radiologic findings developed in this study represented its natural clinical course and clinicopathologic features well.

Lung carcinoma with diffuse cystic lesions misdiagnosed as pulmonary langerhans cell histocytosis: a case report

BACKGROUND

Cystic airspace is an uncommon imaging manifestation involved in non-small lung cancer (NSCLC). Diffuse cystic lesion is even rarer as pulmonary manifestation of NSCLC. In the present study, we reported a rare case of NSCLC associated with progressive diffusion of cystic lesions misdiagnosed as Pulmonary langerhans cell histocytosis (PLCH), finally diagnosed by transbronchial cryobiopsy (TBCB).

CASE PRESENTATION

A 52-year-old woman was admitted to our hospital due to cough and dyspnea. High-resolution computed tomography (HRCT) presented diffuse cystic shadow mostly, concomitantly with nodular densities in bilateral lungs. A lung biopsy revealed poorly differentiated adenocarcinoma with vascular tumor emboli. The epidermal growth factor receptor (EGFR) mutation on exon 18 (G719X, G719) was detected by mutation test. The patient received treatment of tyrosine kinase inhibitor (afatinib).

CONCLUSIONS

Diffuse cystic lesion can be a rare manifestation of lung cancer. It was important to improve the recognition of diffuse cystic lung diseases to avoid misdiagnosis.

Can pseudocavitation in lung tumors predict the diagnosis of adenocarcinoma with lepidic growth?

OBJECTIVE

To determine the prevalence of pseudocavitation in lung tumors and whether its presence makes it possible to predict the diagnosis of adenocarcinoma with lepidic growth.

MATERIAL AND METHODS

We retrospectively reviewed chest CT studies for 212 consecutive lung tumors included in a CT perfusion database and for 351 consecutive adenocarcinomas diagnosed between July 2007 and September 2017. Two radiologists blinded to the pathology report determined whether air cysts were present in the tumors, excluding lesions with necrosis and those surrounded by bullae or emphysema. We analyzed whether the presence of pseudocavitation was associated with the histologic type, size, or EGFR positivity of the tumor as well as with the age or sex of the patient. We also evaluated the relationship with the histologic subtype of the tumor in patients who underwent surgery. We used the chi-square test for categorical variables and logistic regression for continuous variables.

RESULTS

Pseudocavitation was present in 15% of the tumors and was significantly more common in adenocarcinomas (24.1%), p=0.003, although it was also observed in 9.8% of the epidermoid carcinomas and in 3% of the microcytic carcinomas. For the diagnosis of adenocarcinoma, the presence of pseudocavitation yielded 92.4% specificity, 24% sensitivity, 73.3% PPV, 58.4% NPV, and 37.6% accuracy. In the resected adenocarcinomas, 65% of the tumors with pseudocavitation had lepidic growth; the prevalence of pseudocavitation was 40.6% in tumors with lepidic growth, 31.5% in those with acinar growth, and 33% in those with papillary growth. Pseudocavitation was significantly more common in women (29%); no differences were found with respect to age, size, or EGFR positivity.

CONCLUSIONS

Pseudocavitation is more common in adenocarcinomas with lepidic growth and in women.

Lung cancers associated with cystic airspaces: CT features and pathologic correlation

OBJECTIVE

Lung cancer associated with cystic airspaces (LCCA) is a rare entity. The diagnosis and treatment is often delayed due to lack of comprehension of this disease. We aimed to elucidate LCCA's clinicopathological characteristics and investigate imaging features correlated with pathological invasiveness.

METHOD

The preoperative computed tomographic (CT) scans of 10,835 patients diagnosed with NSCLC between January 2015 and December 2016 were reviewed by two thoracic radiologists for association with a cystic airspace. A clinicopathological and radiological feature analysis was done.

RESULT

A total number of 123 LCCA patients were identified and four morphologic patterns were recognized: I, thin-walled type (n = 23, 18.7%); II, thick-walled type (n = 34, 27.6%); III, a cystic airspace with a mural nodule (CWN) type (n = 43, 35.0%); and IV, mixed type (n = 23, 18.7%). A solid component in the cyst wall predicted histological invasiveness in all four types of LCCA. The proportion of moderately/poorly (M/P)-differentiated subtype in type III (85.0%) was higher than in other three patterns (which were 50.0%, 50.0%, and 69.6%, respectively). Multivariate analysis revealed that type III pattern (odds ratio [OR], 6.5; 95% confidence interval [CI], 1.1-36.4; P = 0.035), part-solid/solid component in wall (part-solid: OR, 27.2; 95% CI, 5.6-3131.6; P < 0.001; solid: OR 614.6; 95% CI, 36.4-10,368.6; P < 0.001), and irregular inner surface of cyst (OR 7.0; 95% CI 1.9-26.2; P = 0.004) were independent risk factors for the M/P-differentiated subtype. EGFR mutations were the predominant genetic alterations in each type of LCCAs, but no significant difference was found among them.

CONCLUSIONS

In LCCA, morphological patterns and wall components were two important predictors for determining pathological invasiveness.

Diagnostic and clinical features of lung cancer associated with cystic airspaces

"Lung cancer associated with cystic airspaces" is an uncommon manifestation, in which lung cancer presents on imaging studies with a cystic area with associated consolidation and/or ground glass. With the widespread use of computed tomography (CT), both in clinical practice and for lung cancer screening, these tumors are being more frequently recognized. An association of this entity with smoking has been established with the majority of cases reported being in former and current smokers. The true pathogenesis of the cystic airspace is not yet fully understood. Different causes of this cystic airspace have been described, including a check-valve mechanism obstructing the small airways, lepidic growth of adenocarcinoma on emphysematous lung parenchyma, cyst formation of tumor and tumor growth along the wall of a pre-existing bulla. Adenocarcinoma is the commonest histological type, followed by squamous cell carcinoma. Two classification systems have been described, based on morphological features of the lesion, taking into account both the cystic airspace as well as the morphology of the surrounding consolidation or ground glass. The cystic component may mislead radiologists to a benign etiology and the many different faces on imaging can make early diagnosis challenging. Special attention should be made to focal or diffuse wall thickening and consolidation or ground glass abutting or interspersed with cystic airspaces. Despite their atypical morphology, staging and management currently are still similar to that of other lung cancer types. Although the rarity of this entity will hamper larger studies, numerous aspects regarding this particular lung cancer type still need to be unraveled. This manuscript reviews the CT-imaging findings and gives an overview of available data in the English literature on pathogenesis, histopathology and clinical findings. Differential diagnosis and pitfalls are discussed as well as future directions regarding staging and management.

Cyst-related primary lung malignancies: an important and relatively unknown imaging appearance of (early) lung cancer

It is well known that lung cancer can manifest itself in imaging as solid and subsolid nodules or masses. However, in this era of increased computed tomography use another morphological computed tomography appearance of lung cancer is increasingly being recognised, presenting as a malignancy in relation to cystic airspaces. Despite the fact that it seems to be a relatively common finding in daily practice, literature on this entity is scarce and presumably the overall awareness is limited. This can lead to misinterpretation and delay in diagnosis and, therefore, increased awareness is urgently needed. This review aims to illustrate the imaging appearances of cyst-related primary lung malignancies, demonstrate its mimickers and potential pitfalls, and discuss the clinical implications based on the available literature and our own experience in four different hospitals.

Updated Fleischner Society Guidelines for Managing Incidental Pulmonary Nodules: Common Questions and Challenging Scenarios

The new guidelines for managing incidental pulmonary nodules published by the Fleischner Society in 2017 reflect an improved understanding of the risk factors and biologic features of lung cancer. Specific topics emphasized in the updated guidelines include a new threshold size for follow-up, the importance of the morphologic features of nodules, accurate nodule measurements, recognition of subsolid components, understanding interval growth or change in nodule morphology, and knowledge of patient risk factors. The updated guidelines enable greater personal flexibility in the decision-making process and encourage individualized management of pulmonary nodules. These factors may introduce new challenges for radiologists, who previously used solely nodule size to make management recommendations. The authors describe eight scenarios that illustrate the challenges potentially encountered when applying the new guidelines to pulmonary nodule management. ^©RSNA, 2018.

Solitary thin-walled cystic lung cancer with extensive extrapulmonary metastasis: A case report and review of the literature

RATIONALE

Asymptomatic, isolated, and thin-walled cystic lung cancer with extensive extrapulmonary metastasis is rare, and the risk of pulmonary cyst developing into lung cancer is poorly understood. The efficacy of apatinib for end-stage pulmonary adenosquamous carcinoma has not been clarified yet.

PATIENT CONCERNS

We herein report a rare case of primary lung cancer that appeared as an isolated thin-walled cystic lesion on computed tomography (CT) image, who was initially misdiagnosed as having pulmonary cyst empirically.

DIAGNOSES

Fluorine-18-fluorodeoxyglucose-positron emission tomography and CT-guided liver biopsy of the patient revealed extra-pulmonary metastasis of lung cancer.

INTERVENTIONS

Eight cycles of cisplatin-based chemotherapy were administered, followed by oral apatinib for 6 months. Thereafter, best supportive care was given for this patient.

OUTCOMES

The pulmonary cystic lesion indicated stable disease through the therapy, but the hepatic tumors were progressed gradually after anticancer treatment. The patient died 16 months after the correct diagnosis.

LESSONS

Solitary thin-walled cystic lung cancer should be kept in mind during the differential diagnosis of pulmonary cavitary lesions. Chest CT alone is insufficient for surveillance of these cystic diseases. Timely biopsy and resection are essential to avoid delayed management. Besides, apatinib may play a role in the treatment of end-stage pulmonary adenosquamous carcinoma.

Lung cancer screening: nodule identification and characterization

The accurate identification and characterization of small pulmonary nodules at low-dose CT is an essential requirement for the implementation of effective lung cancer screening. Individual reader detection performance is influenced by nodule characteristics and technical CT parameters but can be improved by training, the application of CT techniques, and by computer-aided techniques. However, the evaluation of nodule detection in lung cancer screening trials differs from the assessment of individual readers as it incorporates multiple readers, their inter-observer variability, reporting thresholds, and reflects the program accuracy in identifying lung cancer. Understanding detection and interpretation errors in screening trials aids in the implementation of lung cancer screening in clinical practice. Indeed, as CT screening moves to ever lower radiation doses, radiologists must be cognisant of new technical challenges in nodule assessment. Screen detected lung cancers demonstrate distinct morphological features from incidentally or symptomatically detected lung cancers. Hence characterization of screen detected nodules requires an awareness of emerging concepts in early lung cancer appearances and their impact on radiological assessment and malignancy prediction models. Ultimately many nodules remain indeterminate, but further imaging evaluation can be appropriate with judicious utilization of contrast enhanced CT or MRI techniques or functional evaluation by PET-CT.

Impact of the favorable prognosis of patients with lung cancer adjoining bullae

Background

Lung cancer adjoining bullae (LC-AB) is an uncommon manifestation. The clinical characteristics and prognosis of LC-AB remain unclear. The aim of this study is to investigate the clinical features and overall survival (OS) of patients with LC-AB following lung resection compared to non-LC-AB group.

Methods

We retrospectively investigated 291 consecutive patients with lung cancer who underwent curative resection in a single institution between April 2007 and March 2015. A total of LC-AB was 52 patients. LC-AB was determined using thin slice computed tomography (CT) imaging and pathological findings. Survival analysis was calculated using the Kaplan-Meier method. We used a Cox proportional hazards model for the univariate and multivariate analysis to identify prognostic factors.

Results

The LC-AB group showed a higher frequency of younger patients (P=0.017), former or current smokers (P=0.011), men (P=0.021), tumor location in the upper lobe (P=0.031), moderately or poorly differentiated tumor histology (P<0.001), pleural indentation (P=0.007), and non-adenocarcinoma histology (P=0.016) than the non-LC-AB group. The 5-year survival and recurrence-free survival (RFS) rates were significantly higher in the LC-AB group than the non-LC-AB group (88.5% vs. 74.9%, P=0.010, 75.4% vs. 61.3%, P=0.030, respectively). Multivariate analysis using a Cox proportional hazard model of OS showed that LC-AB was an independent prognostic factor [hazard ratio (HR): 0.30, 95% confidence interval (CI): 0.12-0.77, P=0.012].

Conclusions

Patients with LC-AB had better OS than those with non-LC-AB. Thus, LC-AB may be an independent favorable prognostic factor following curative resection.

Thin-wall cystic lung cancer: A study of 45 cases

Thin-wall cystic lung cancer is uncommon. Consequently, there is a lack of knowledge concerning the features of this type of lung cancer, which may lead to misdiagnosis and delayed treatment. The aim of the present study is to understand the invasiveness and metastasis of thin-wall cystic lung cancer. The prognosis of this type of cancer will also be discussed. The present study attempted to determine the pathological interpretation of the imaging results. A total of 45 patients with this specific type of lung cancer were analyzed retrospectively based on the review of medical records, radiological findings, pathological changes and treatment strategies. Certain patients were also telephoned in order to learn about their recent physical conditions. Thin-wall cystic lung cancer displayed suspected malignant signs. The majority of these cases are adenocarcinoma, but certain cases of squamous cell carcinoma may also display cysts on their images. Although thin-wall cystic lung cancer is often thought to progress slowly, certain cases may progress rapidly. Distant metastasis, which is relatively rare, occurred in three cases. Cancer cells proliferate along the terminal bronchioles and destroy the lung tissues exposing the bronchial arteries and adjacent bronchi. Therefore, separation in cysts on the images was observed. In the majority of cases, the thin-wall cystic lung cancer proliferates slowly, but in a few cases it may be very aggressive.

Missed Lung Cancer

The chest radiograph is one of the most commonly used imaging studies and is the modality of choice for initial evaluation of many common clinical scenarios. Over the last two decades, chest computed tomography has been increasingly used for a wide variety of indications, including respiratory illnesses, trauma, oncologic staging, and more recently lung cancer screening. Diagnostic radiologists should be familiar with the common causes of missed lung cancers on imaging studies in order to avoid detection and interpretation errors. Failure to detect these lesions can potentially have serious implications for both patients as well as the interpreting radiologist.