CT differentiation of pneumonic-type bronchioloalveolar cell carcinoma and infectious pneumonia

Radiological and clinical features of large consolidative-type pulmonary invasive mucinous adenocarcinoma

BACKGROUND

This study aimed to investigate the radiological, pathological, and prognostic characteristics of large consolidative-type pulmonary invasive mucinous adenocarcinomas (IMA).

METHODS

We retrospectively reviewed 738 patients who confirmed IMA between January 2010 and August 2022, and two radiologists reviewed imaging data to determine subtypes. We included 41 patients with pathologically large consolidative-type IMA. We analyzed their radiological, pathological, and prognostic characteristics. The recurrence-free survival (RFS) and overall survival (OS) were determined using the Kaplan-Meier method.

RESULTS

Most lesions were located in the lower lobe, with 46.3% patients showing multiple lesions. Halo, angiogram, vacuole, air bronchogram, and dead branch sign were observed in 97.6%, 73.2%, 63.4%, 61.0%, and 61.0% of the cases, respectively. Unevenly low enhancement was observed in 88.89% of patients. T3 and T4 pathological stages were observed in 50.0% and 30.6% of patients, respectively. Lymph node metastasis was observed in 16.7% patients, with no distant metastasis. Spread-through air spaces and intrapulmonary dissemination were observed in 27.8% and 19.4% patients, respectively. Moreover, Kirsten rat sarcoma viral oncogene mutations were found in 68.6% of cases, and no epidermal growth factor receptor mutations were seen. Among all mutation sites, G12V mutation is the most common, accounting for 40%. The average RFS and OS were 19.4 and 66.4 months, respectively, with 3-year RFS and OS rates of 30.0% and 75.0%, respectively. Pleural invasion and lymph node metastasis were independent risk factors for diagnosis.

CONCLUSION

Halo, vacuole, angiogram, and dead branch signs were frequently observed in consolidative-type IMA. Kirsten rat sarcoma viral oncogene mutations are common in consolidative-type IMA, especially site G12V, whereas epidermal growth factor receptor mutations were rare; therefore, gene immunotherapy was more difficult. Most patients were in stage T3-T4; however, lymph node metastasis was rare.

Clinicopathologic Features and Survival Outcomes of Primary Lung Mucinous Adenocarcinoma Based on Different Radiologic Subtypes

BACKGROUND

Primary lung mucinous adenocarcinomas (LMAs) could be subclassified as the pure-solid, part-solid, and pneumonic types according to the findings of high-resolution computed tomography. This study aimed to expound on the clinicopathologic, radiologic, and prognostic characteristics of LMAs based on radiologic classification within a large set of patients.

METHODS

From November 2009 to December 2016, this study enrolled 294 resected LMAs, which were divided into the pure-solid (n = 169), part-solid (n = 87), and pneumonic (n = 38) types. The clinicopathologic and radiologic characteristics of the tumors were evaluated, and patient prognosis was determined through follow-up evaluation. Survival outcomes were calculated by Kaplan-Meier curves and compared using log-rank tests. The prognostic impact of clinicopathologic variables, including radiologic presentations, were evaluated by establishing a Cox proportional hazards model.

RESULTS

The LMAs were infrequently associated with lymph node metastasis (5.4 %), lymphatic/vascular invasion (4.4 %), or visceral pleural invasion (5.1 %). During the median 71-month follow-up period, recurrence was observed in 62 patients and death in 44 patients. The patients with pneumonic-type LMAs had a poorer prognosis (5-year recurrence-free survival [RFS], 23.7 %; 5-year overall survival [OS], 44.7 %) than those with the pure-solid type (RFS, 83.2 %; OS, 100 %) or part-solid type (RFS, 93.7 %; OS, 100 %). Besides, lymph node metastasis, emphysema, and clinical T stage were independent predictors of RFS and OS.

CONCLUSION

Solitary-type LMA patients had excellent prognoses, whereas the survival outcomes for pneumonic-type LMA patients were dismal. Furthermore, pneumonic-type LMA patients were prone to intrapulmonary metastasis by means of aerogenous dissemination rather than distant metastasis.

Mucinous Adenocarcinoma of the Lung: A Great Mimicker of Pneumonia

Mucinous adenocarcinoma is a rare lung cancer that can mimic the appearance of infectious pneumonia on imaging. The present report describes the case of an 88-year-old man who presented with a cough that was not responsive to treatment. Based on chest X-ray findings consistent with pneumonia, he was treated with oral antibiotics. After the patient's symptoms did not improve, a computed tomography scan was performed, which showed a confluent consolidation in the left lower lung and a cavitation suggestive of pneumonia. The patient was then admitted to the hospital to receive intravenous antibiotics. Although his cough continued, laboratory findings were within normal ranges and bacterial cultures were negative. He underwent two bronchoscopy procedures with bronchoalveolar lavage and was diagnosed with parainfluenza and rhinovirus/enterovirus, for which he was treated with prolonged antibiotics and steroids. His symptoms still failed to improve, and a bronchoscopy with cryobiopsy was performed, with a positive result for mucinous adenocarcinoma. This case illustrates the need to distinguish mucinous adenocarcinoma from pneumonia to improve the early diagnosis of this rare cancer and patient outcomes.

Adenosquamous carcinoma lung radiologically mimicking pneumonia: A potentially disastrous diagnostic challenge in an unusual malignancy

Lung cancer is among the most frequently diagnosed cancers and the world's leading cause of cancer-related death. Radiology remains the mainstay for timely diagnosis; however, atypical radiologic patterns are known, and these may be misdiagnosed as infectious or inflammatory pathology, particularly in the absence of smoking history. We report herein an account of an older male nonsmoker who presented radiologically with bilateral diffuse pulmonary infiltrates, simulating pneumonia, but was eventually diagnosed with adenosquamous lung carcinoma. The delay in diagnosis and subsequent unfortunate rapid deterioration of our patient serves as a reminder for clinicians to consider lung cancer in patients with clinical/radiologic findings suggestive of pneumonia, especially in nonsmokers or cases refractory to antibiotic therapy.

A 52-Year-Old Man Who Smokes With Rapidly Progressive Respiratory Failure

CASE PRESENTATION

A 52-year-old White man, who currently smokes, was admitted to the medical ICU with worsening shortness of breath. The patient was dyspneic for a month and had been clinically diagnosed with COPD by his primary care doctor and started on bronchodilators and supplemental oxygen. He had no known medical history or recent illness. His dyspnea worsened rapidly over the next month, prompting admission to the medical ICU. He was on high-flow oxygen followed by noninvasive positive pressure ventilation and then mechanical ventilation. He denied cough, fever, night sweats, or weight loss at the time of admission. There was no history of work-related or occupational exposures, drug intake, or recent travel. Review of systems was negative for arthralgia, myalgia, or skin rash.

Pulmonary Adenocarcinoma Mimicking Pneumonia in a Young Adult

Lung cancer is the third most common cancer in the United States. Lung adenocarcinoma is a subtype of non-small cell lung cancer. On computed tomography (CT) it can appear as ground glass nodules, consolidative opacity, or solid mass lesions located in the periphery. Because it can appear as a consolidation, it can sometimes be confused with an infectious process such as pneumonia. We present a case of a 27-year-old male initially diagnosed with pneumonia; however, three months later, when he presented to the hospital with worsening pleuritic chest pain, fever, and dyspnea after a bronchoscopy a week before admission, pathology was positive for adenocarcinoma.

Nomogram Using CT Radiomics Features for Differentiation of Pneumonia-Type Invasive Mucinous Adenocarcinoma and Pneumonia: Multicenter Development and External Validation Study

BACKGROUND. Pneumonia-type invasive mucinous adenocarcinoma (IMA) and pneumonia show overlapping chest CT features as well as overlapping clinical characteristics. OBJECTIVE. The purpose of our study was to develop and validate a nomogram combining clinical and CT-based radiomics features to differentiate pneumonia-type IMA and pneumonia. METHODS. This retrospective study included 314 patients (172 men, 142 women; mean age, 60.3 ± 14.5 [SD] years) from six hospitals who underwent noncontrast chest CT showing consolidation and were diagnosed with pneumonia-type IMA (n = 106) or pneumonia (n = 208). Patients from three hospitals formed a training set (n = 195) and a validation set (n = 50), and patients from the other three hospitals formed the external test set (n = 69). A model for predicting pneumonia-type IMA was built using clinical characteristics that were significant independent predictors of this diagnosis. Radiomics features were extracted from CT images by placing ROIs on areas of consolidation, and a radiomics signature of pneumonia-type IMA was constructed. A nomogram for predicting pneumonia-type IMA was constructed that combined features in the clinical model and the radiomics signature. Two cardiothoracic radiologists independently reviewed CT images in the external test set to diagnose pneumonia-type IMA. Diagnostic performance was compared among models and radiologists. Decision curve analysis (DCA) was performed. RESULTS. The clinical model included fever and family history of lung cancer. The radiomics signature included 15 radiomics features. DCA showed higher overall net benefit from the nomogram than from the clinical model. In the external test set, AUC was higher for the nomogram (0.85) than for the clinical model (0.71, p = .01), radiologist 1 (0.70, p = .04), and radiologist 2 (0.67, p = .01). In the external test set, the nomogram had sensitivity of 46.9%, specificity of 94.6%, and accuracy of 72.5%. CONCLUSION. The nomogram combining clinical variables and CT-based radiomics features outperformed the clinical model and two cardiothoracic radiologists in differentiating pneumonia-type IMA from pneumonia. CLINICAL IMPACT. The findings support potential clinical use of the nomogram for diagnosing pneumonia-type IMA in patients with consolidation on chest CT.

Pneumonic-type invasive mucinous adenocarcinoma and infectious pneumonia: clinical and CT imaging analysis from multiple centers

Background

Pneumonic-type invasive mucinous adenocarcinoma (IMA) was often misdiagnosed as pneumonia in clinic. However, the treatment of these two diseases is different.

Methods

A total of 341 patients with pneumonic-type IMA (n = 134) and infectious pneumonia (n = 207) were retrospectively enrolled from January 2017 to January 2022 at six centers. Detailed clinical and CT imaging characteristics of two groups were analyzed and the characteristics between the two groups were compared by χ2 test and Student’s t test. The multivariate logistic regression analysis was performed to identify independent predictors. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of different variables.

Results

A significant difference was found in age, fever, no symptoms, elevation of white blood cell count and C-reactive protein level, family history of cancer, air bronchogram, interlobular fissure bulging, satellite lesions, and CT attenuation value (all p < 0.05). Age (odds ratio [OR], 1.034; 95% confidence interval [CI] 1.008–1.061, p = 0.010), elevation of C-reactive protein level (OR, 0.439; 95% CI 0.217–0.890, p = 0.022), fever (OR, 0.104; 95% CI 0.048–0.229, p < 0.001), family history of cancer (OR, 5.123; 95% CI 1.981–13.245, p = 0.001), air space (OR, 6.587; 95% CI 3.319–13.073, p < 0.001), and CT attenuation value (OR, 0.840; 95% CI 0.796–0.886, p < 0.001) were the independent predictors of pneumonic-type IMA, with an area under the curve of 0.893 (95% CI 0.856–0.924, p < 0.001).

Conclusion

Detailed evaluation of clinical and CT imaging characteristics is useful for differentiating pneumonic-type IMA and infectious pneumonia.

A Case of Invasive Mucinous Adenocarcinoma with Acute Respiratory Distress Syndrome Diagnosed by Autopsy Findings

We herein report a fatal case of invasive mucinous adenocarcinoma (IMA) with acute respiratory distress syndrome (ARDS) diagnosed based on autopsy findings. A 76-year-old man presented with severe respiratory discomfort on admission. Computed tomography (CT) revealed a peripheral distribution of consolidation. Although his respiratory status improved after steroid therapy, re-exacerbation occurred, and the patient died on day 131. A bronchoscopic lung biopsy had shown organizing pneumonia, but a post-mortem examination surprisingly revealed IMA with organizing pneumonia. IMA presenting with ARDS as the first symptom is extremely rare.

Differential diagnosis of localized pneumonic-type lung adenocarcinoma and pulmonary inflammatory lesion

BACKGROUND

In clinical practice, a number of delayed diagnoses of localized pneumonic-type lung adenocarcinoma (L-PLADC) mimicking pneumonia have been identified due to the lack of knowledge regarding the radiological findings associated with this condition. Here, we defined L-PLADC as a special type of lung adenocarcinoma that presents as a focal consolidation involving < 50% of the area of a lobe and aimed to investigate the differential clinical and imaging features between L-PLADC and localized pulmonary inflammatory lesion (L-PIL).

RESULTS

The data of 120 patients with L-PLADC and 125 patients with L-PIL who underwent contrast-enhanced chest computed tomography (CT) scan were retrospectively analyzed. For clinical characteristics, older age, women, nonsmokers, and no symptom were more common in L-PLADC (all p < 0.001). With regard to CT features, air bronchogram, irregular air bronchogram, ground-glass opacity (GGO) component, and pleural retraction were more frequently observed in L-PLADC, while necrosis, satellite lesions, halo sign, bronchial wall thickening, interlobular septa thickening, pleural attachment, and pleural thickening were more commonly seen in L-PIL (all p < 0.001). Multivariate analysis showed age ≥ 58 years, female sex, GGO component, irregular air bronchogram, pleural retraction, and the absence of necrosis and pleural attachment were the most effective variations associated with L-PLADC with an AUC of 0.979. Furthermore, an external validation cohort containing 62 patients obtained an AUC of 0.929.

CONCLUSIONS

L-PLADC and L-PIL have different clinical and imaging characteristics. An adequate understanding of these differential features can contribute to the early diagnosis of L-PLADC and the subsequent therapeutic strategy.

Pneumonic-type lung adenocarcinoma with different ranges exhibiting different clinical, imaging, and pathological characteristics

Background

Pneumonic-type lung adenocarcinoma (PLADC) with different ranges might exhibit different imaging and clinicopathological features. This study divided PLADC into localized PLADC (L-PLADC) and diffuse PLADC (D-PLADC) based on imaging and aimed to clarify the differences in clinical, imaging, and pathologic characteristics between the two new subtypes.

Results

The data of 131 patients with L-PLADC and 117 patients with D-PLADC who were pathologically confirmed and underwent chest computed tomography (CT) at our institute from December 2014 to December 2020 were retrospectively collected. Patients with L-PLADC were predominantly female, non-smokers, and without respiratory symptoms and elevated white blood cell count and C-reactive protein level, whereas those with D-PLADC were predominantly male, smokers, and had respiratory symptoms and elevated white blood cell count and C-reactive protein level (all p < 0.05). Pleural retraction was more common in L-PLADC, whereas interlobular fissure bulging, hypodense sign, air space, CT angiogram sign, coexisting nodules, pleural effusion, and lymphadenopathy were more frequent in D-PLADC (all p < 0.001). Among the 129 patients with surgically resected PLADC, the most common histological subtype of L-PLADC was acinar-predominant growth pattern (76.7%, 79/103), whereas that of D-PLADC was invasive mucinous adenocarcinoma (80.8%, 21/26). Among the 136 patients with EGFR mutation status, L-PLADC had a significantly higher EGFR mutation rate than D-PLADC (p < 0.001).

Conclusions

L-PLADC and D-PLADC have different clinical, imaging, and pathological characteristics. This new imaging-based classification may help improve our understanding of PLADC and develop personalized treatment plans, with concomitant implications for patient outcomes.

Invasive Mucinous Adenocarcinoma of the Lung Presenting With Multiple Cavities

A 78-year-old woman presented to our hospital with a two-week history of productive cough. Chest computed tomography (CT) showed bilateral multiple pulmonary nodules with cavities. Although the cytology of her sputum revealed adenocarcinoma, she refused any treatment. Following supportive care, 30 months later, she presented to our hospital with dyspnea and fever. Chest CT showed progression of multiple pulmonary nodules and cavities. Despite treatment with antibiotics and palliative care, she died on the 10th day of hospitalization. Pathological autopsy confirmed the diagnosis of pulmonary invasive mucinous adenocarcinoma (IMA). The typical CT findings of IMA include multiple consolidations or ground-glass opacities mimicking pneumonia; rarely, cavitary lesions are also observed. Clinicians should consider IMA as a differential diagnosis for lung cavities.

Necrotizing pneumonia (aetiology, clinical features and management)

PURPOSE OF REVIEW

Necrotizing pneumonia is a severe form of community-acquired pneumonia characterized by rapid progression of consolidation to necrosis and cavitation which may lead to pulmonary gangrene. Morbidity and mortality are high and chronic sequelae are frequent. The lack of guidance supports the review of the latest recommendations in the management of these pneumonias.

RECENT FINDINGS

Antibiotic therapy alone may not be enough to alter the course of the infection, and regimens, adjunctive therapies like intravenous immunoglobulins, surgery may be required to alter the course of the disease especially with pulmonary gangrene.

SUMMARY

The causative agents, clinical features and management of necrotizing pneumonias are discussed.

Role of Percutaneous Computed Tomography-guided Lung Biopsy in Non-resolving Consolidation and Identification of Clinical and High-resolution Computed Tomography Characteristics Predicting Outcome

Objective:

Non-resolving consolidation (NRC) with inconclusive sputum, bronchoscopy, and bronchoalveolar lavage results poses a diagnostic dilemma. This retrospective analytical study was conducted to evaluate diagnostic yield and complications of percutaneous computed tomography (CT)-guided lung biopsy (PCLB) in NRC. Assessment of clinical features and high-resolution CT (HRCT) characteristics was also done which may predict outcome.

Materials and Methods:

Data of PCLB performed for lung consolidation from January 2010 to January 2019 were retrospectively evaluated. For the determination of diagnostic yield, a positive result from any one specimen obtained by PCLB (tissue core, aspiration cytology, or microbiology) was sufficient to considered procedure diagnostic if it was concordant with clinical features, imaging findings, response to treatment, and subsequent follow-up. Student’s t-test and Fisher’s exact test were used for statistical analysis.

Results:

Out of total 56 patients, final diagnosis was achieved in 48 (19 malignant and 29 benign). Diagnostic yield was 69.6%. Complications were noted in 10 patients including mild hemoptysis and pneumothorax, which were managed conservatively. No clinical feature was having statistically significant association with final diagnosis. HRCT findings significantly associated with malignant outcome were larger size of consolidation, multiple contiguous lobe involvement, multiple air-filled cysts inside consolidation, and associated ground-glass areas or multiple ground-glass nodules. The absence of air bronchogram was more common in benign cases.

Conclusion:

PCLB is a safe and useful method for obtaining specimen in NRC. Differentiation of benign from malignant outcome is not possible based on clinical findings; however, certain HRCT findings raise suspicion of malignancy.

Unusual presentation of primary lung adenocarcinoma mimicking pneumonia: Case report and literature review

Primary lung adenocarcinoma, diffuse pneumonic type, can mimic the clinical presentation of an infectious or inflammatory lung disease, which can represent a diagnostic challenge. We present an unusual case of adenocarcinoma of the lung refractory to treatment, associated with rapid deterioration of respiratory status, ARDS requiring intubation and ultimately death.

Clinical characteristics and prognosis of nonsurgically treated patients with pneumonic-type adenocarcinoma

Pneumonic-type adenocarcinoma (P-ADC) is a subtype of lung adenocarcinoma with high mortality, which often requires lobectomy surgery. Nonsurgically treated P-ADC patients usually have more advanced or complex conditions, which remain poorly understood and pose a major challenge in clinical management. We aimed to describe the clinical profiles and prognosis of non-surgically treated P-ADC patients. We enrolled 71 patients with pathologically proven P-ADC from a university hospital in China. Clinical and laboratory data were retrieved from medical record. Their median age was 62 years, including 45% men and 35% smokers. Clinical manifestations were dominated by cough, sputum, and dyspnea. Main chest imaging features included nodules, shadow, consolidation, and air bronchogram. Nearly half or more of patients showed higher levels of inflammation and cancer biomarkers including cytokeratin-19-fragment (CYFRA 21-1) and carcinoembryonic antigen (CEA). Majority of patients were classified at the stage IIIB or IV. Palliative care was the most popular treatment option but provided a shorter overall survival compared to tyrosine kinase inhibitor therapy, standard chemotherapy, and sequential therapy while there were no significant differences in the survival among the latter 3 options. Higher serum CEA was associated with longer survival and better prognosis while higher serum CYFRA 21-1 could predict a poor prognosis. Detailed understanding the clinical characteristics and prognostic factors in nonsurgically treated P-ADC may allow the identification of patients with particular risk factors and initiation of early and specific treatment in order to optimize outcomes.

Computerized margin and texture analyses for differentiating bacterial pneumonia and invasive mucinous adenocarcinoma presenting as consolidation

Radiologists have used margin characteristics based on routine visual analysis; however, the attenuation changes at the margin of the lesion on CT images have not been quantitatively assessed. We established a CT-based margin analysis method by comparing a target lesion with normal lung attenuation, drawing a slope to represent the attenuation changes. This approach was applied to patients with invasive mucinous adenocarcinoma (n = 40) or bacterial pneumonia (n = 30). Correlations among multiple regions of interest (ROIs) were obtained using intraclass correlation coefficient (ICC) values. CT visual assessment, margin and texture parameters were compared for differentiating the two disease entities. The attenuation and margin parameters in multiple ROIs showed excellent ICC values. Attenuation slopes obtained at the margins revealed a difference between invasive mucinous adenocarcinoma and pneumonia (P<0.001), and mucinous adenocarcinoma produced a sharply declining attenuation slope. On multivariable logistic regression analysis, pneumonia had an ill-defined margin (odds ratio (OR), 4.84; 95% confidence interval (CI), 1.26–18.52; P = 0.02), ground-glass opacity (OR, 8.55; 95% CI, 2.09–34.95; P = 0.003), and gradually declining attenuation at the margin (OR, 12.63; 95% CI, 2.77–57.51, P = 0.001). CT-based margin analysis method has a potential to act as an imaging parameter for differentiating invasive mucinous adenocarcinoma and bacterial pneumonia.

Pulmonary cryptococcosis manifesting as diffuse air-space consolidations in an immunocompetent patient

Pulmonary cryptococcosis is an opportunity infection commonly occurred in the immunocompromised patients. However pulmonary cryptococcosis in the immunocompetent was reported up to 35% and these cases tend to show confined and localized radiologic findings than in immunocompromised patients. To our knowledge, extensive air-space consolidations have not frequently occurred in the immunocompetent patient. Therefore, in this case, we report a rare case of a 73-year-old woman who was diagnosed with pulmonary cryptococcosis, manifesting as diffuse air-space consolidations even though normal immune status. Thus, the possibility of pulmonary cryptococcosis should be considered when a patient with a normal immune status presents without respiratory symptoms are accompanied by consolidation on imaging.

Clinical course of stage IV invasive mucinous adenocarcinoma of the lung

INTRODUCTION

An invasive mucinous adenocarcinoma (IMA) is a distinct lung adenocarcinoma variant. The characteristics of stage IV IMAs are relatively unclear since most previous studies described resected cases from stage I to III. The present study aimed to investigate the clinical course of stage IV IMAs and compare the findings to those of stage IV invasive non-mucinous adenocarcinomas (INMAs).

METHODS

The study included 36 IMA patients and 210 INMA patients. The clinicopathological parameters, treatment methods and responses, overall survival (OS), and progression-free survival (PFS) were evaluated.

RESULTS

IMAs were predominantly located in the lower lobes and frequently presented with multifocal consolidation and lung-to-lung or pleural metastasis. KRAS mutations were noted in 60.0% of the examined IMAs. Non-TKI chemotherapy (CTx) was used in 72.2% of the IMA patients. OS was significantly better in untreated IMA patients than in untreated INMA patients. IMA patients treated with non-TKI CTx had no improvement of OS compared to the untreated IMA patients. However, among INMA patients, OS was best with TKIs in patients harbouring targetable mutations, followed by non-TKI CTx. IMA and INMA patients treated with non-TKI CTx had similar PFS.

CONCLUSIONS

Stage IV IMAs have distinct clinicopathological characteristics, and they might be less aggressive than INMAs. Since non-TKI CTx might not be beneficial in IMA patients, new therapeutic approach is necessary.

Recurrent "pneumonia" in left lower lobe lasting for 8 years: a case report

Bronchioloalveolar carcinoma (BAC) is a unique lung neoplasm with variable forms, such as single nodular, multifocal and lobar pneumonic types. The pneumonic type BAC is often difficult to differentiate from pneumonia. Here we present a case of 63-year-old Chinese male, who had recurrent cough, white sputum with pneumonic lesions in left lower lobe. He suffered from lung biopsies for three times, and finally diagnosed as high differentiated adenocarcinoma 8 years later. He was treated with four cycles of pemetrexed and cisplatin, and four cycles of docetaxel and nedaplatin. However, he did not achieve disease stabilization and is still under follow up. This case suggests that, pneumonic type adenocarcinoma may radiographically and clinically resemble infectious pneumonia. Lack of fever and leukocytosis, no response to antibiotics, air bronchogram, and accompanied nodules or patches in computed tomography (CT) scans should raise suspicion about the diagnosis of pneumonia. Lung biopsy might be the only means of ruling in a diagnosis of BAC.

The IASLC Lung Cancer Staging Project: Background Data and Proposals for the Application of TNM Staging Rules to Lung Cancer Presenting as Multiple Nodules with Ground Glass or Lepidic Features or a Pneumonic Type of Involvement in the Forthcoming Eighth Edition of the TNM Classification

INTRODUCTION

Application of tumor, node, and metastasis (TNM) classification is difficult in patients with lung cancer presenting as multiple ground glass nodules or with diffuse pneumonic-type involvement. Clarification of how to do this is needed for the forthcoming eighth edition of TNM classification.

METHODS

A subcommittee of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee conducted a systematic literature review to build an evidence base regarding such tumors. An iterative process that included an extended workgroup was used to develop proposals for TNM classification.

RESULTS

Patients with multiple tumors with a prominent ground glass component on imaging or lepidic component on microscopy are being seen with increasing frequency. These tumors are associated with good survival after resection and a decreased propensity for nodal and extrathoracic metastases. Diffuse pneumonic-type involvement in the lung is associated with a worse prognosis, but also with a decreased propensity for nodal and distant metastases.

CONCLUSION

For multifocal ground glass/lepidic tumors, we propose that the T category be determined by the highest T lesion, with either the number of tumors or m in parentheses to denote the multifocal nature, and that a single N and M category be used for all the lesions collectively-for example, T1a(3)N0M0 or T1b(m)N0M0. For diffuse pneumonic-type lung cancer we propose that the T category be designated by size (or T3) if in one lobe, as T4 if involving an ipsilateral different lobe, or as M1a if contralateral and that a single N and M category be used for all pulmonary areas of involvement.

Aerogenous metastases: a potential game changer in the diagnosis and management of primary lung adenocarcinoma

OBJECTIVE

The purposes of this article are to summarize the relevant literature on aerogenous metastasis, explain the putative pathogenetic mechanism of aerogenous spread, present the characteristic imaging and pathologic features, and review the importance of aerogenous spread to staging and clinical management.

CONCLUSION

Cumulative evidence suggests that aerogenous spread may exist and is underrecognized. Imaging features are helpful in differentiating possible aerogenous spread of tumor from hematogenous and lymphatic metastases and from synchronous primary tumors. The putative occurrence of intrapulmonary aerogenous metastasis of lung cancer has staging, management, and prognostic implications.

High incidence of EGFR mutations in pneumonic-type non-small cell lung cancer

To retrospectively identify computed tomography (CT) features that correlate with epidermal growth factor receptor (EGFR) mutation in surgically resected pneumonic-type lung cancer (P-LC). A total of 953 consecutive patients with surgically resected lung cancer in the First Affiliated Hospital of Guangzhou Medical University from August 2011 to August 2013 were studied. The CT manifestations were reevaluated independently by 2 radiologists. The presence of pneumonic-type consolidation with pathological confirmed non-small lung cancer (NSCLC) was defined as P-LC. EGFR mutation was determined by direct DNA sequencing or amplification refractory mutation system-PCR. EGFR mutation rates as well as clinical and pathological manifestations between P-LC and control lung cancer patients were compared. P-LC was diagnosed in 85 patients. Among these patients, 82 were adenocarcinoma (including 78 cases of invasive adenocarcinoma and 4 cases of microinvasive adenocarcinoma), 2 were squamous carcinoma and 1 was other type. P-LC occurred more frequently in female (58.8% vs 37.1%, P < 0.01), nonsmoking (76.5% vs 56.5%, P = 0.001) and adenocarcinoma (58.8% vs 37.1%, P < 0.01) patients. Moreover, EGFR mutations were found in 39 of 52 P-LC patients (75%) and 263 of 542 non-P-LC NSCLC patients (48.5%). However, no difference was found on the mutation sites of EGFR. Histological type, sex, and radiological manifestations (P-LC vs non-P-LC) but not smoking or sequencing method can be served as the independent predictor of EGFR mutations. P-LC patients showed a significant higher incidence of EGFR mutations, which was independent of sex, histological type, and smoking history. The patients with imaging manifestation of pneumonic-type consolidation are highly suggested to perform EGFR mutation analysis to guide the sequential treatment.

Imaging of Pulmonary Infections

Pulmonary infection is one of the most frequent causes of morbidity and mortality throughout the world. Many infections occur in individuals with concomitant intrapulmonary or extrathoracic diseases; however, they commonly develop in otherwise healthy people. In the non-immunocompromised population, pneumonia is the most prevalent community-acquired infection and the second most common nosocomial infectious disorder. In immunocompromised patients, in children, and in the elderly, pneumonia, as well as other pulmonary infections, may develop into a life-threatening condition.

Case report: Positron emission tomography fails to detect pulmonary adenocarcinoma recurrence after radiofrequency ablation

We describe the case of late recurrence of a focus of invasive mucinous adenocarcinoma (formerly mucinous bronchioloalveolar carcinoma) following radiofrequency ablation, despite a negative positron emission tomography/computed tomography scan at 13 months following the ablation. A computed tomography scan performed at 24 months demonstrated unequivocal recurrence of the lesion. Combined positron emission tomography/computed tomography has been described as an adequate modality for the follow-up of thermally ablated pulmonary lesions. However, its utility in the follow-up of well-differentiated pulmonary adenocarcinoma may be limited. Lesion activity may be underestimated by an inherently low metabolic activity. Small lesions may also be susceptible to partial volume effect. Long-term imaging follow-up of well-differentiated pulmonary adenocarcinoma beyond two years after thermal ablation is prudent to avoid missing late recurrence.

Aspects of bronchioloalveolar carcinoma and of adenocarcinoma with a bronchioloalveolar component: CT findings

Bronchioloalveolar carcinoma has various presentations and a wide spectrum of imaging patterns, as does adenocarcinoma with a bronchioloalveolar component. The objective of this essay was to describe and illustrate the CT findings that are most characteristic of these tumors. Three presentations are described: solitary pulmonary nodule, consolidation, and diffuse pattern. The last two should be included in the differential diagnosis, together with infectious diseases. Knowledge of the various presentations and the use of proper diagnostic procedures are crucial to early diagnosis and to improving survival.

[Imaging of pneumonia]

Pneumonien stellen ein Krankheitsbild mit hoher epidemiologischer, klinischer und auch ökonomischer Relevanz dar. Die bildgebende Diagnostik spielt eine wichtige Rolle bei der Detektion, Differenzierung und Verlaufskontrolle pneumonischer Infiltrate. Selbst in der Computertomographie (CT) ist jedoch die Morphologie einer infiltrativen Erkrankung sehr unspezifisch. Rückschlüsse auf zugrunde liegende Erreger sind daher grundsätzlich schwierig, und nichtinfektiöse Differenzialdiagnosen müssen berücksichtigt werden. Die Kenntnis spezieller Erscheinungsformen, Verteilungsmuster und Differenzialdiagnosen pneumonischer Infiltrate sowie die Mitbeurteilung des klinischen Gesamtkontextes helfen jedoch bei der Eingrenzung auf die relevanten Differenzialdiagnosen und des Erregerspektrums. Der CT des Thorax kommt dabei speziell bei opportunistischen Infektionen und bei Patienten unter intensivmedizinischer Behandlung eine besondere Bedeutung zu.

Sclerosing variant of the bronchioloalveolar carcinoma: imaging findings in an atypical case

Bronchioloalveolar carcinoma remains one of the most enigmatic lung cancers, demonstrating varied growth patterns, mixed histological features, and confusing clinical manifestations. This paper reports a case of an unusual form of presentation: a sclerosing type associated with desmoplastic reaction and cicatrization. A 75-year-old woman was admitted with persistent dry cough and progressive dyspnea. Physical examination showed bilateral inspiratory crackles. A chest radiograph and high-resolution computed tomography demonstrated confluent airspace nodules, forming areas of consolidation in both lungs, with signs of architectural distortion. The lung biopsy revealed a nonmucinous sclerosing bronchioloalveolar carcinoma.

CT-guided biopsy of nonresolving focal air space consolidation

OBJECTIVES

To evaluate the diagnostic accuracy of percutaneous computed tomography (CT)-guided coaxial core needle biopsy in patients with nonresolving pulmonary focal air space consolidations and negative fiberoptic bronchoscopy results.

METHODS

From 1997 to 2005, 23 patients (11 woman, 12 men; age range, 45 to 81 y; mean age, 66 y) presenting with nonresolving pneumonia persisting more than 8 weeks (mean, 22 wk; range, 8 to 40 wk) with negative fiberscopic results, underwent coaxial percutaneous biopsy using an automated core needle (18-gauge) under CT guidance. Histologic and bacteriologic evaluations were obtained. The final diagnosis was confirmed by surgical pathology, culture results, or clinical follow-up.

RESULTS

Specimens adequate for histopathologic evaluations were obtained in 20 (87%) cases. Final diagnoses were lung cancer (n=15) and benign diseases (infectious pneumonia, 3; lipoid pneumonia, 1; Erdheim Chester disease: 1; and nonspecific chronic pneumonia, 3). Diagnostic yield of core needle biopsy was 78% (18 of 23). The sensitivity and specificity for malignancy were 87% and 100%, respectively. Immediate pneumothorax was present in 11 patients of cases, but only 2 patients required pleural drainage.

DISCUSSION

CT-guided lung biopsy using a core needle biopsy provides a high degree of diagnostic accuracy and allows specific characterization of nonresolving pulmonary focal air space consolidation.

Pictorial review of the many faces of bronchioloalveolar cell carcinoma

Bronchioloalveolar cell carcinoma (BAC) has a varied appearance on CT that often leads to an incorrect or delayed diagnosis. The purpose of this pictorial review is to define common CT characteristics that are specific to BAC. A retrospective review was undertaken of 20 CT scans of pathologically proven cases of BAC; tumours were categorized as focal or diffuse, single or multiple, and infiltrative or well defined. Additional radiological features noted include the density (solid, part solid, non-solid), the presence of unaffected vessels within the tumour(s), and the presence of internal air bronchograms. We illustrate cases of localized and diffuse BAC presenting as (i) solitary or multiple pulmonary nodules, with and without air bronchograms, (ii) bubble-like lucencies of pseudocavitation associated with nodules of varying density, (iii) unifocal or multifocal ground-glass opacities, (iv) crazy paving, (v) nodules and airspace opacities with unaffected vessels coursing through them and (vi) lobar or multilobar consolidation and cavitating nodules. In conclusion, BAC may present with a variety of CT appearances. However, there are typical features such as the CT-angiogram sign or air-brochochograms in solitary nodules and in the periphery of larger consolidations, persisting pure ground-glass opacities, unresolving consolidation and the combination of diffuse nodules and consolidation. These features should alert the radiologist to the diagnosis of BAC.

Diagnosis and treatment of bronchioloalveolar carcinoma

PURPOSE OF REVIEW

Bronchioloalveolar carcinoma accounts for 5% of lung cancers, although histologically mixed bronchioloalveolar carcinoma and adenocarcinoma account for up to 20%. Bronchioloalveolar carcinoma histology is present in a majority of tumors found on lung-cancer screening by computed tomography. We review issues surrounding the diagnosis and treatment of bronchioloalveolar carcinoma, which often differs from other types of lung cancer.

RECENT FINDINGS

A spectrum of disease from histologically pure bronchioloalveolar carcinoma to adenocarcinoma exists. The approach to treatment of diseases within this spectrum is still evolving. Evidence on the role of sub-lobar resection, resection of multifocal disease, and pulmonary transplantation is reviewed. We also discuss epidermal growth factor receptor tyrosine kinase inhibitors, and their role in patients with bronchioloalveolar carcinoma.

SUMMARY

An understanding of recent developments in the diagnosis and treatment of patients with bronchioloalveolar carcinoma histology is important as early detection of lung cancer becomes more common. Ongoing clinical trials will provide important information on the role of limited resection. The use of epidermal growth factor receptor tyrosine kinase inhibitors should currently be limited to patients with advanced or recurrent disease who have failed cytotoxic chemotherapy. New targeted therapies are emerging for patients with bronchioloalveolar carcinoma histology.

Bronchioloalveolar carcinoma: a review

Bronchioloalveolar carcinoma (BAC) is classified as a subset of lung adenocarcinoma but has a distinct clinical presentation, tumor biology, response to therapy, and prognosis compared with other subtypes of non-small-cell lung carcinoma (NSCLC). Bronchioloalveolar carcinoma disproportionately affects women, never-smokers, and Asians and is characterized by growth along alveolar septae without evidence of stromal, vascular, or pleural invasion. Although pure BAC accounts for approximately 4% of lung cancers, tumors with histologically mixed BAC and adenocarcinoma account for > 20% of all NSCLCs, and the incidence of BAC might be increasing. Bronchioloalveolar carcinoma histology is most commonly found in small lesions identified incidentally on chest radiographs or computed tomography scans and might represent a precursor lesion to invasive adenocarcinoma. As with other subsets of NSCLC, surgical resection is the only potentially curative treatment. Patients with unresectable BAC are more likely to respond to the epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib than patients with other subtypes of NSCLC. Stage for stage, patients with BAC have a higher rate of long-term survival but might have an increased rate of intrathoracic recurrence than patients with other subtypes of NSCLC.

Mucin-producing adenocarcinoma of the lung: thin-section computed tomography findings in 48 patients and their effect on prognosis

OBJECTIVE

To determine the prognostic value of thin-section computed tomography (CT) findings in patients with mucin-producing adenocarcinoma (MPA) of the lung.

METHODS

The study included 48 patients with pathologically proven MPA who had thin-section CT before treatment. The CT findings were correlated with the histopathologic findings and with disease-free survival on follow-up in all patients.

RESULTS

Computed tomography findings identified in patients with MPA of the lung included an air bronchogram (n = 37, 77.1%), areas of ground-glass attenuation (n = 36, 75.0%), areas of air-space consolidation (n = 36, 75.0%), interlobular septal thickening (n = 33, 68.8%), bubble-like lucencies (n = 23, 47.9%), centrilobular nodules (n = 22, 45.8%), and mucus filling of airways (n = 19, 39.6%). Twenty-two (45.8%) of the 48 patients had intrapulmonary metastases. Centrilobular nodules (odds ratio [OR] = 6.7, 95% confidence interval: 1.1-41.4; P < 0.05) and mucus filling of airways (OR = 14.4, 95% 95% confidence interval: 2.0-102.7; P < 0.01) on thin-section CT were independently associated with an increased likelihood of intrapulmonary metastases. The 5-year disease-free survival rates were 67.9% and 38.4% for patients without and with intrapulmonary metastases, respectively (P < 0.05). The presence of centrilobular nodules (relative risk = 10.5, 95% confidence interval: 1.8-59.3; P < 0.01) on thin-section CT was an independent predictor of poor prognosis.

CONCLUSION

Centrilobular nodules on CT are associated with a higher prevalence of intrapulmonary metastases and a poor prognosis in patients with MPA of the lung.

Bronchioloalveolar carcinoma with fluctuating extent of consolidation on chest radiography

We report a case of bronchioloalveolar carcinoma that required approximately 1 year to diagnose due to alternating periods of exacerbation and improvement of abnormal opacity on chest radiography. It is important to consider the diagnosis of bronchioloalveolar carcinoma when consolidative opacities simulating pneumonia show an alternating pattern of worsening and improvement.