Etiology and outcome of community-acquired lung abscess.

BACKGROUND: Anaerobes are the first and Streptococcus species the second most common cause of community-acquired lung abscess (CALA) in the West. The etiologic pathogens of this disease have changed in Taiwan, with Klebsiella pneumoniae being reported as the most common cause of CALA. OBJECTIVE: To determine the etiologies of community-acquired lung abscess. METHODS: We retrospectively reviewed the records of 205 Japanese adult patients with CALA to evaluate etiologies and outcomes. We used not only traditional microbiological investigations but also percutaneous ultrasonography-guided transthoracic needle aspiration and protected specimen brushes. RESULTS: Of these 205 patients, 122 had documented bacteriological results, with 189 bacterial species isolated. Pure aerobic, mixed aerobic and anaerobic, and pure anaerobic bacteria were isolated in 90 (73.8%), 17 (13.9%), and 15 (12.3%) patients, respectively. The four most common etiologic pathogens were Streptococcus species (59.8%), anaerobes (26.2%), Gemella species (9.8%), and K. pneumoniae (8.2%). Streptococcus mitis was the most common among the Streptococcus species. Mean duration of antibiotic administration was 26 days. Six patients (2.9%, 3 with actinomycosis and 3 with nocardiosis) were treated with antibiotics for 76-189 days. Two patients with anaerobic lung abscess died. CONCLUSIONS: The first and second most common etiologic pathogens of CALA in our hospital were Streptococcus species and anaerobes, respectively. The etiologies in our study differ from those in Taiwan and are similar to those in the West with the exception that Streptococcus species were the most common etiologic pathogens in our study whereas anaerobes are the most frequent etiologic pathogens in Western countries. S. mitis and Gemella species are important etiologic pathogens as well. The identification of Actinomyces and Nocardia is important in order to define the adequate duration of antibiotic administration.

[Severe complications and their outcomes in 65 patients with Legionella pneumonia].

The aim of the current study was to investigate the lethal complications of Legionella pneumonia. Severe complications and their outcomes in 65 patients with Legionella pneumonia were studied. All patients who eventually had a fatal outcome or who had severe complications received antimicrobial agents active against Legionella on the admission day. Many patients in the severe complication category had multiple severe complications. Six deaths occurred (mortality rate 9.2%), 4 of which were due to septic shock/multiple organ dysfunction syndrome (MODS) (2 patients) or interstitial pneumonia/pulmonary fibrosis after Legionella pneumonia (2 patients), whereas the other 2 deaths were due to causes unrelated to Legionella pneumonia. Mortality rates for each severe complication were as follows: acute respiratory distress syndrome 27.3% (3 of 11); renal failure 33.3% (2 of 6); disseminated intravascular coagulation 33.3% (2 of 6); severe sepsis 0% (0 of 1); septic shock/MODS 66.7% (2 of 3); interstitial pneumonia/pulmonary fibrosis 50% (2 of 4). Despite prompt diagnosis and appropriate treatment with antimicrobial agents active against Legionella, the lethal complications of Legionella pneumonia are septic shock/MODS and interstitial pneumonia/pulmonary fibrosis.

[Nemaline myopathy detected with respiratory failure and right ventricular heart failure].

We describe the case of a 40-year-old woman who was admitted for dyspnea and pitting edema of the lower extremities. Severe type II respiratory failure and right ventricular heart failure were present. Non-invasive positive pressure ventilation (NIPPV) improved the symptoms and blood gas values. Since the results of respiratory function tests and computed tomography indicated neuromuscular disease, muscle biopsy was performed and nemaline myopathy was diagnosed. NIPPV was necessary due to severe hypoxia and hypercapnia caused by severe hypoventilation during sleep; however, daytime NIPPV was stopped within a few days, and the patient was discharged with instructions to continue NIPPV at night only. Since discharge, she has been followed-up on an outpatient basis for 8 years. Adult-onset nemaline myopathy with respiratory failure and right ventricular heart failure as presenting features is rare, and NIPPV can be useful in such cases.

[Case of hot tub lung with confirmation of exacerbation following jet bath use].

A 49-year-old woman presented with exertional dyspnea. Chest CT revealed patchy areas of ground-glass attenuation and ill-defined centrilobular nodules scattered in both lungs. Bronchoalveolar lavage (BAL) fluid showed lymphocytosis. Transbronchial lung biopsy revealed bronchiolocentric alveolitis and well-formed non-necrotizing granulomas were present. She had used a jet bath before the onset of symptoms and mycobacterial culture revealed the presence of Mycobacterium avium complex (MAC) in sputum sample, BAL samples and jet bath water. Restriction fragment length polymorphism (RFLP) analysis revealed that the isolated MAC were essentially clonal. She had used the jet bath for the inhalation provocation study, and after the challenge she complained of dyspnea and have body temperature increased. We diagnosed hot tub lung due to Mycobacterium avium complex. Because avoidance of the jet bath caused improvement of her symptoms and reduced her fever and PaO2 increased by 10 Torr but did not improve the CT findings, antimycobacterial drugs were prescribed. The patient recovered fully. This case proves that the cause of hot tub lung is the use of jet bath through the inhalation provocation study.

[Case of pneumonia caused by beta-lactamase-producing and amoxicillin/clavulanate resistant strains of H. influenzae].

An 80-year-old woman presenting with fever and cough was given a diagnosis of community-acquired pneumonia. She was hospitalized and treated with ampicillin/sulbactam (ABPC/SBT) and clarithromycin (CAM). Gram stain images and sputum culture results led us to believe that the causative agent was Haemophilus influenzae. Drug sensitivity testing indicated that the H. influenzae was a beta-lactamase-positive, ABPC-resistant (BLPAR) strain. Treatment with ABPC/SBT was not clinically effective. We considered the possibility of beta-lactamase-positive amoxicillin/clavulanate-resistant (BLPACR) strains. Further testing revealed that the MIC of ABPC was 128 microg/ml, that of SBT/ABPC was 8 microg/ml, and that of AMPC/CVA was 4 microg/ml. Furthermore, genetic analysis indicated the H. influenzae to be a BLPACR-I strain. The poor clinical course eventually led to a diagnosis of BLPACR. When beta-lactamase-producing H. influenzae is cultured, the possibility of a BLPACR strain resistant to ABPC/SBT and AMPC/CVA must be considered.

[Lung cancer associated with rheumatoid arthritis and usual interstitial pneumonia].

UNLABELLED: To assess the effects of usual interstitial pneumonia (UIP) and smoking in rheumatoid arthritis (RA) patients regarding lung cancer risk, we studied 86 RA patients (14 patients with lung cancer, 58 patients with UIP (RA/ UIP), and 14 patients with both). Among the 28 RA patients with lung cancer, 14 patients (50%) had UIP. Compared to the lung cancer patients without UIP, the proportion of smokers (92.6 vs 50%, p = 0.0328) and total pack-years of smoking (57.1 +/- 37.1 vs 19.5 +/- 21.9, p = 0.003) were significantly higher in lung cancer patients with UIP. There was no significant difference in age, sex, and histological type and location of lung cancer between these two groups. Among the 72 RA/UIP patients, 14 patients (19.4%) had lung cancer. Compared to RA/UIP-only patients, the proportion of smokers (92.6 vs 46.6%, p = 0.002) and total pack-years of smoking (57.1 +/- 37.1 vs 25.4 37.4, p = 0.006) were significantly higher in RA/UIP patients with lung cancer. There was no significant difference in age, sex, and the duration of RA between these two groups. The odds ratio of smoking and total pack-years of smoking over 20 for the development of lung cancer in RA/UIP patients were 14.93 and 21.27, and the differences were statistically significant (p = 0.002 and p < 0.001, respectively). CONCLUSION: 50% of RA patients with lung cancer had RA/UIP and 19.4% of RA/UIP patients had lung cancer. These findings suggest that RA/UIP may be associated with increased risk of development of lung cancer in RA patients. In an RA cohort study to assess the development of lung cancer, RA patients should be divided into two groups, one with RA/UIP and another without RA/UIP. Smokers with RA/UIP should be recommended to cease smoking.

[Clinical features of mixed infections in patients with Streptococcus pneumoniae pneumonia].

We retrospectively analyzed the severity, the mortality and the initial antimicrobial therapy in 195 patients with Streptococcus pneumoniae pneumonia (SPP). Of these, 59 (30.3%) patients had mixed pneumonia. In patients with mixed SPP, the three most frequent pathogens were influenza virus (27 patients), Haemophilus infuluenzae (14 patients), and Mycoplasma pneumoniae (8 patients). Of these, 21 (35.5%) patients were classified as severe or very severe according to the Japanese Respiratory Society diagnostic criteria among 59 patients of mixed SPP. Severe and very severe pneumonia was significantly associated with mixed infections (P = 0.018). The initial antimicrobial therapy was classified as beta-Lactam alone (113 patients), combination therapy including a beta-Lactam (72 patients), and a fluoroquinolone alone (10 patients). If we limit out study to mild-moderate pneumonia, initial combination therapy was significantly effective in patients with mixed SPP. Even in pneumonia caused by Streptococcus pneumoniae, further efforts to identify etiology are necessary.

Development of sarcoidosis during etanercept therapy.

This report describes a 65-year-old woman who developed granulomatous lesions consistent with sarcoidosis during etanercept therapy for rheumatoid arthritis. Hilar and mediastinal lymphadenopathy and multiple nodules in both lung fields developed 21 months after administration of etanercept. Noncaseating epithelioid cell granulomas consistent with sarcoidosis were detected in a lung biopsy specimen and in the parietal pleura obtained via thoracotomy. Diseases showing similar histologic changes were excluded, and a diagnosis of sarcoidosis was made. Etanercept was discontinued, which resulted in symptomatic relief, improvement of oxygenation and radiologic findings. There is substantial evidence of tumor necrosis factor-alpha involvement in the induction and maintenance of granuloma formation; however, we should keep in mind that granulomatous disease, such as sarcoidosis, can develop during treatment with a tumor necrosis factor-alpha blocking agent, such as etanercept.

[A case of rheumatoid arthritis complicated with methotrexate-induced pneumonitis and pneumocystis pneumonia].

A 62-year-old woman with rheumatoid arthritis was given 4 mg/body methotrexate (MTX) every week and 5 mg prednisolone every day. She developed a severe cough starting in the evening after starting taking MTX and after a fever of 38 degrees and dyspnea appeared the patient was hospitalized. On admission, chest CT findings showed diffuse ground glass attenuation. Pathological findings of specimens obtained by transbronchial lung biopsy showed alveolitis with epithelioid cell granuloma. As a section of the specimen did not show cyst staining by Grocott stain, MTX-induced pneumonitis was diagnosed. The same day, methylprednisolone pulse therapy was started and trimethoprim-sulfamethoxazole (TMP-SMX) was given simultaneously, while MTX was discontinued. On hospital day 3, subsequent data showed a high serum level of beta-D glucan and a positive PCR result for Pneumocystis jiroveci in bronchoalveolar lavage fluid (BALF). Additional section of the specimen showed eosinophilic foamy areas on HE staining and cysts measuring 8 microm, consistent with the Pneumocystis jiroveci lesions by Grocott stain. We present a case of rheumatoid arthritis complicated by methotrexate-induced pneumonitis in which pneumocystis pneumonia was demonstrated by clinical and pathological findings.

Desquamative interstitial pneumonia with a remarkable increase in the number of BAL eosinophils.

A 57-year old man with desquamative interstitial pneumonia (DIP) showed a marked increase in eosinophils in the bronchoalveolar lavage (BAL) fluid. The patient was referred to our hospital for abnormal shadows on his chest X-ray with no symptoms in May 2007. Computed tomography (CT) showed patchy, peripheral predominate ground-glass opacity. The BAL fluid revealed an increase of the total number of cells, including markedly elevated levels of eosinophils (62.1%), in contrast with only a slight increase of peripheral blood eosinophils, or minimal eosinophils in the alveolar spaces and interstitium of the thoracoscopic lung biopsy specimen. Since the specimens showed findings compatible with a DIP pattern, we diagnosed the patient with DIP. Although it is a rare entity, we should therefore consider DIP in the differential diagnosis when we encounter patients with a marked increase in the number of BAL eosinophils.

[Pulmonary infections in patients with rheumatoid arthritis].

We studied 149 rheumatoid arthritis (RA) patients (mean age 68.0 years; 68 men, 81 women) with pulmonary infections. The mean age at the onset of RA and the duration of RA was 57.2 +/- 15.2 years and 10.9 +/- 11.5 years, respectively. Pulmonary infections included nontuberculous mycobacteriosis in 59 patients (Mycobacterium avium complex infection, 50 cases : Mycobacterium kansasii infection, 4 cases; others, 5 cases), pneumonia in 46 patients, pulmonary tuberculosis in 28 patients, pulmonary aspergillosis in 12 patients, pulmonary cryptococcosis in 5 patients, Pneumocystis jiroveci pneumonia in 5 patients, lung abscess in 9 patients, exacerbation of bronchiectasis in 7 patients, and empyema in 4 patients. One hundred percent of patients with exacerbation of bronchiectasis, 91.7% of patients with pulmonary aspergillosis, 87% of patients with pneumonia, and 81.4% of patients with nontuberculous mycobacteriosis had underlying lung diseases. The pulmonary infections during therapy with steroids were pulmonary tuberculosis (78.6%), pneumonia (65.2%), and pulmonary aspergillosis (58.3%), while the pulmonary infections during methotrexate treatment were Pneumocystis jiroveci pneumonia (80%), pulmonary cryptococcosis (40%), and pulmonary tuberculosis (28.6%). Pulmonary infections in RA patients who were taking TNFalpha inhibitors included 1 patient each with nontuberculous mycobacteriosis, pneumonia, pulmonary tuberculosis, and Pneumocystis jiroveci pneumonia. Among the RA patients with lung abscess, malignancy was noted in 55.6%, and diabetes mellitus in 22.2%. Pseudomonas aeruginosa was the second-most-common cause of pneumonia and cause of all exacerbations of bronchiectasis. As well as immunosuppressive medications (steroids, methotrexate, TNFalpha inhibitors) and systemic comorbid diseases, underlying lung diseases could be one of the risk factor for pulmonary infections in patients with RA. The dominant risk factor for each pulmonary infection in patients with RA might be different.

[Pneumocystis carinii pneumonia in a patient with hyper-IgE syndrome].

A 15-year-old girl with abnormal findings detected on a medical check-up chest x-ray film was admitted to our center. High-resolution computed tomography, performed upon hospitalization, demonstrated panlobular nodular darkening in left lung fields, and an expanding, blended, map-like darkening near the pleura. Since a Grocott stain-positive cyst was confirmed histopathologically by transbronchial lung biopsy, the patient was given a diagnosis of Pneumocystis carinii pneumonia. Drug therapy was initiated with sulfamethoxaxole trimethoprim (Baktar), and on the 58th day, chest CT confirmed that the darkening observed at admission had virtually disappeared. Underlying diseases, such as AIDS, malignant lymphoma and secondary immunodeficiency caused by immunosuppressive agents or adrenocorticosteroids, were excluded as the cause of P. carinii pneumonia based on clinical/laboratory findings. Under the suspicion of the possibility of primary immunodeficiency, various immunological competence tests were performed. However, no abnormal findings indicating cell-mediated immunity, humoral immunity, complement immune function, neutrophil phagocytic capacity, or bactericidal capacity were recognized. Since significant increase of serum IgE suggested hyper-IgE syndrome, IgE antibody specific to Staphylococcal enterotoxin A and B, and the exotoxins of Staphylococcus aureus were measured with positive results. Since all three diagnostic criteria for hyper-IgE syndrome (i.e., high serum IgE values, positive IgE antibody specific to Staphylococcal enterotoxin and recurrent infection) were fulfilled, hyper-IgE syndrome was diagnosed. This is a rare case of hyper-IgE syndrome as a result of P. carinii pneumonia.

Pulmonary Schizophyllum commune infection developing mucoid impaction of the bronchi.

A 54-year-old woman was admitted for cough, sputum, and an abnormal chest X-ray shadow. Bronchoscopy showed mucoid impaction of the bronchi (MIB). Histopathologic evidence of mucous plugs was consistent with one component of allergic bronchopulmonary mycosis. Schizophyllum commune (S. commune) was identified. Two attempts at removal of the mucous plugs were unsuccessful. Itraconazole was then administered, and the mucous plugs disappeared. There are few reports of MIB due to S. commune; we herein report a case of MIB due to S. commune infection.

[Clinical features and outcome in 84 patients with influenza pneumonia].

We examined the clinical features, illness types of pneumonia, efficacy of neuraminidase inhibitors and outcome in patients with influenza pneumonia. Eighty-four patients with influenza pneumonia, in whom the diagnosis was confirmed by serology or rapid diagnostic tests, were studied. Because neuraminidase inhibitors were given prior to the onset of pneumonia in some patients with secondary bacterial pneumonia, we examined the efficacy of neuraminidase inhibitors in patients other than the secondary bacterial pneumonia group. Influenza A was detected in 71% of the subjects, and influenza B in 29% who showed a clinical presentation and outcome similar to those patients with influenza A. Primary influenza viral pneumonia was observed in 27% of the subjects, mixed viral and bacterial pneumonia in 38%, secondary bacterial pneumonia in 18%, and unclassified type of pneumonia in 17%, respectively. Eighty-three percent of the subjects had underlying diseases. The overall mortality rate was 9.5%, and all 8 fatal cases had comorbidities. Thirty-nine percent were aged under 65 years and 3 fatal cases were aged under 65 years. The mortality rates of patients receiving or not receiving neuraminidase inhibitor were 4.9% and 14.3%, respectively. Due to the small number of patients and the fact that this case was not a controlled study, the efficacy of neuraminidase inhibitors for influenza pneumonia was not proved.

[Clinical study of 90 cases of Mycoplasma pneumoniae pneumonia].

We investigated 90 patients with Mycoplasma pneumoniae (M. pneumoniae) pneumonia. Forty-four patients were men, 46 were women and the mean age was 43.1 years old. Twenty-nine patients were smokers and 28 had underlying diseases. As for diagnostic method, 16 were culture positive, 71 had a fourfold increase in antibody titer to M. pneumoniae, and 3 were both culture positive and had a fourfold increase in antibody titer. Regarding the degree of severity, 21 patients were classified as severe according to Japanese Respiratory Society diagnostic criteria, 11 patients were diagnosed as severe according to American Thoracic Society diagnostic criteria. Partial pressure of arterial oxygen (PaO2) of 18 patients were <60mmHg, 5 patients were under mechanical ventilation, and 3 patients died. Three of 16 patients treated with only beta-lactum antibiotics recovered. The 3 patients who died were M. pneumoniae culture-positive and two patients had polymicrobial infections. Severe pneumonia associated with Mycoplasma pneumoniae infection is not unusual. If a rapid diagnosis kit or culture method of M. pneumoniae pneumonia is not introduced, the pathogen might be unknown in cases of rapid death due to M. pneumoniae pneumonia. These data suggest that the mortality rate of M. pneumoniae pneumonia might be underestimated without these detection tests.

[Etiology and outcome of community-acquired pneumonia in relation to age and severity in hospitalized adult patients].

The aim of this study was to determine the etiology and outcome of community-acquired pneumonia (CAP) in relation to age and severity in hospitalized patients. Overall, 652 consecutive patients with CAP were studied retrospectively during a 4-year period from 2002. Severity of pneumonia was classified according to the guidelines of the Japanese Respiratory Society (JRS 2005) and American Thoracic Society (ATS 2001). The etiology was identified in 401 of 652 (61.5%) cases. The four most frequent pathogens were Streptococcus pneumoniae (26.2%), influenza virus (12.4%), Mycoplasma pneumoniae (10.9%), and Haemophilus influenzae (5.9%). The most common pathogen in the younger (15-44 years) group and very severe patients (JRS) was Mycoplasma pneumoniae (38.4%) and influenza virus (28.6%), respectively. The three most frequent pathogens in severe CAP patients (ATS) were Streptococcus pneumoniae (29.0%), influenza virus (17.4%), and Legionella species (13.0%). The overall mortality was 6.4%. The mortality of CAP patients among aged 1544, 45-64, 65-74, and 75 years or older was 1.4%, 3.3%, 6.9% and 9.3%, respectively. The mortality of mild, moderate, severe, and very severe patients (RS) was 0%, 4.1%, 15.5%, and 53.6%, respectively. The mortality of non-severe and severe patients (ATS) was 1.8% and 23.9%, respectively. Age and severity had influence on the prevalence of the main microbial pathogens. Streptococcus pneumoniae remained the most important pathogen that needs consideration in initial antibiotic therapy in patients with CAP of all ages and severities. Pathogens identified in patients with severe CAP in Japan were similar to those of Western countries, except for the high incidence of the influenza virus.

[Pulmonary tuberculosis with cerebellar lesion in a patient after anti-TNF-alpha (infliximab) treatment for rheumatoid arthritis].

We report a case of pulmonary tuberculosis in a 51-year-old Japanese woman, who received treatment with infliximab for active rheumatoid arthritis. She had cough and sputum after the second infusion of the drug, small nodular lesions of right lung field and left lower lobe on her chest CT and a small nodular lesion of right cerebellar lobe on her cranial MRI were identified. Mycobacterium tuberculosis was cultured from her sputum. Therefore, we diagnosed her illness as pulmonary tuberculosis with a cerebellar lesion. The patient was treated with anti-tuberculosis drugs and showed marked improvement in lesions of the lung and brain. We considered this case a tuberculosis reactivation after infliximab treatment because of the short interval between the administration of infliximab and the occurrence of tuberculosis, and the complication of extrapulmonary lesion that suggested brain tuberculoma.

[Community-acquired pneumonia with rhabdomyolysis].

We assessed the frequency and etiology of rhabdomyolysis in patients with community-acquired pneumonia. In 594 patients with community-acquired pneumonia whose serum CPK were measured, 25 patients (2.4%) were found to have rhabdomyolysis. Including 4 patients with mixed infections, the etiologies in 25 patients with community-acquired pneumonia with rhabdomyolysis were as follows: Legionella species, 11 patients (44%); Influenza virus, 6 (24%); Streptococcus pneumoniae, 4 (16%); Chlamydia psittaci, 3 (12%); Mycoplasma pneumoniae, 2 (8%); unknown 3 patients (12%). The rates of rhabdomyolysis for each etiologic category were as follows: Legionella species, 26.8% (11/41); Chlamydia psittaci, 21.4% (3/14); Influenza virus, 9.5% (6/63) ; Streptococcus pneumoniae, 4.7% (4/85);Mycoplasma pneumoniae, 3.1% (2/65). Renal dysfunction with a serum creatinine concentration greater than 1.5 mg/dl occurred in 6 patients (24%). Our experience illustrates that 5 pathogens can cause rhabdomyolysis in patients with community-acquired pneumonia. Legionella species are the most common organisms followed by Influenza virus, Streptococcus pneumoniae, Chlamydia psittaci, Mycoplasma pneumoniae.

[Polymicrobial infections in patients with Legionella pneumonia].

We assessed the frequency and clinical significance of polymicrobial infections in 31 patients with sporadic community-acquired Legionella pneumonia. Twenty-six patients were men, 5 were women and mean age was 61 years. Eighteen patients were smokers, 6 patients were chronic alcoholics and 23 had underlying diseases. Regarding severity, the illnesses were mild (two patients), moderate (seven patients) and severe (twenty-two patients). In 9 (29%) of the patients, one other etiologic agent for community-acquired pneumonia was identified in addition to the Legionella species. The distribution of one other causal agent was as follows: Mycoplasma pneumoniae, 2 patients; Chlamydia pneumoniae, 2; Chlamydia psittaci, 1; Influenza virus, 1; Streptococcus pneumoniae, 1; Klebsiella pneumoniae, 1; Pseudomonas aeruginosa, 1 patient. Because an antimicrobial agent with activity against Legionella species can also provide coverage for Mycoplasma pneumoniae. Chlamydia pneumoniae, and Chlamydia psittaci, the patients with these coinfections improved without any complications. The patient with influenzavirus coinfection became seriously ill, and the condition was complicated by disseminated intravascular coagulation, renal failure and aspergillus bronchitis. The case of Pseudomonas aeruginosa coinfection was accompanied with a lung abscess and empyema. Our experience illustrates the importance of considering polymicrobial infections in patients with sporadic community-acquired Legionella pneumonia.

[Imaging diagnosis for intralobar pulmonary sequestration by subclassification of CT findings in bronchoalveolar structures].

We examined the chest CT findings in 12 cases of intralobar pulmonary sequestration. We classified 4 subtypes by evaluating bronchial and alveolar structures, thus: type A (3 cases), mild cylindrical dilatation of the bronchial structure and hyperlucent alveolar structure; type B (3 cases), marked cylindrical dilatation of the bronchial structure and hyperlucent alveolar structure; type C (2 cases), multicystic dilatation of the bronchial structure and alveolar structure without hyperlucency; and type D (4 cases), multicystic dilatation of the bronchial structure and absence of any alveolar structure. All 77 cases (present and previously reported cases) with CT-documented intralobar pulmonary sequestration could be classified into 4 subtypes: type A 9%, type B 34%, type C 19%, and type D 38%. We concluded that these 4 types were useful for the radiological diagnosis of intralobar pulmonary sequestration.