The pulmonary sequestration corresponds to pulmonary tissue intra or extra-lobar with systemic arterial nutrition and collateral bronchial ramification. It is infrequent and the intra-lobar identification depends on the correct clinical signs and morphology. The correct study includes imagiologic identification of the systemic artery and morphological characterization of parenchymal changes. These allow identification of abnormal pulmonary parenchyma in intra-lobar cases and were observed using histochemical and immunohistochemical routine methods, both in intra and extra-lobar cases. Four cases of intra-lobar sequestration and four cases of extra-lobar sequestration were studied with application of histochemical techniques--Movat's pentachrome stain and Verhoeff--and immunolabelling with CK7 and TTF1. The parenchymal inflammatory distortion by collagenization was constantly seen as was BALT hyperplasia and pleuritis. By using Movat's pentachrome stain we characterized the sequestration by identifying the artery and the parenchymal changes. The CK7 was useful in the identification of parenchymal damage, together with the antibody anti-TTF1 that had a variable expression, stronger in areas of inflammation because of PII hyperplasia.

Pulmonary sequestration: a single-institutional series composed of 27 cases.J Thorac Cardiovasc Surg. 2007 Apr;133(4):955-9.

OBJECTIVE: Large series about pulmonary sequestration from a single institute are rare in the literature. In this study, we aimed to evaluate diagnosis, treatment, and outcomes of pulmonary sequestration in a single institute. METHODS: Records of patients with pulmonary sequestration between January 1982 and January 2006 were reviewed retrospectively. Age, sex, symptoms, diagnostic procedures, operative findings, operative techniques, postoperative complications, and follow-up results were evaluated. RESULTS: Twenty-seven patients, 17 male and 10 female, with an average age of 23.3 were operated on for pulmonary sequestration. Twenty patients had preoperative symptoms including recurrent pneumonia attacks, chest pain, hemoptysis, and shortness of breath. Chest radiography, thoracic computed tomography, aortography, magnetic resonance imaging, and bronchoscopy were used as diagnostic methods. Of the cases, 19 (70%) were intralobar pulmonary sequestration and 8 (30%) were extralobar pulmonary sequestration. Surgical procedures were lower lobectomy in 18 and segmentectomy in 1 of the patients with intralobar pulmonary sequestration and simple mass excision in all of those with extralobar pulmonary sequestration. Postoperative histopathologic examinations excluded any other alternative diagnosis. Furthermore, it detected an aspergilloma ball in 1 of the intralobar pulmonary sequestration specimens. Two patients had a postoperative complication (prolonged air leak in 1 patient and empyema in the other). During the follow-up period (mean 2.3 years), none of the patients presented a problem. No mortality was encountered. CONCLUSION: Owing to the potentially severe complications they can cause, pulmonary sequestrations should be removed whenever they are diagnosed. Since careful dissection provides sufficient surgical comfort, preoperative identification of the aberrant vessels is not a rule for the success of the operation.

Infradiaphragmatic extralobar pulmonary sequestration.Rofo. 2006 Nov;178(11):1115-20.

PURPOSE: To demonstrate characteristic imaging findings in infradiaphragmatic extralobar pulmonary sequestration (IEPS) with special emphasis on ultrasound (US). MATERIALS AND METHODS: The imaging material (pre- and postnatal US in all cases, magnetic resonance imaging (MRI) in 2 cases) for 4 infants (3 girls, 1 boy) was reviewed. 2 patients underwent surgery (after birth and at 4 months of age, respectively) and the diagnosis of IEPS was confirmed. The other 2 patients were monitored conservatively using US for up to 15 months. RESULTS: All 4 left-side suprarenal masses exhibited the same characteristic sono-morphology, leading to the suspected diagnosis of IEPS. The masses were small (max. 10 ml), hyperechoic with cystic components and without calcifications, well demarcated and separate from the normal kidney and the suprarenal gland, and without any change in prenatal and directly postnatal size. Doppler US showed low-grade perfusion in all cases and an aberrant systemic artery originating from the abdominal aorta in 2 cases. MRI did not add any fundamental information. Despite the suspected imaging diagnosis of IEPS and negative urinalyses for neuroblastoma, 2 patients underwent surgery for histological confirmation. The lesions in the other 2 patients were monitored via US. A complete disappearance after 4 months in one patient and a continuous decrease in size over 15 months in the other patient were documented. CONCLUSION: Based on the characteristic findings of prenatal and postnatal US, IEPS can be diagnosed reliably. With the knowledge of its benign spontaneously regressing behavior, suspected suprarenal lesions should be treated conservatively via US monitoring.

Bronchopulmonary sequestration--a 12-year experience.Rev Port Pneumol. 2006 Sep-Oct;12(5):489-501.

Bronchopulmonary sequestration (BPS) is a rare malformation of the lower respiratory tract. It consists of a non-functioning mass of lung tissue that lacks normal communication with the tracheobronchial tree and that receives arterial blood supply from the systemic circulation. It is classified as intralobar (ILS) or extralobar (ELS) according to its location within or outside the normal lung. Most sequestrations are intralobar (75%) and occur predominantly in the left lower lobe.

Pulmonary sequestration--a review of 8 cases treated with lobectomy. Scand J Surg. 2006;95(3):190-4

BACKGROUND AND AIMS: Pulmonary sequestration (PS) is a rare congenital malformation where non-functioning lung tissue is separated from the bronchial tree and vascularised with an aberrant artery from the systemic circulation. The aim of this report was to study all patients who were treated for PS at Lund University Hospital between 1994 and 2004, with emphasis on clinical presentation of the disease and evaluate the results of surgical treatment. MATERIAL AND METHODS: 8 cases were identified, 7 females and one male, with a mean age of 7.3 years (range 25 days -17 years) at the time of diagnosis. RESULTS: Out of 8 patients, seven presented with respiratory symptoms and two with congestive heart failure. Five patients had other congenitial malformations; including scimitar syndrome and congenital heart disease. All the patients underwent a successful lobectomy. There were no major postoperative complications. At a medium follow-up of 77 months all of the fully treated children were doing well. CONCLUSION: Respiratory and cardiovascular symptoms are the most common symptoms related to PS. The wide range of clinical symptoms may cause diagnostic problems, especially in children and young adults with concomitant congenital heart disease. Therefore PS should be considered as a differential diagnosis in children with unexplained respiratory symptoms or with signs of congestive heart failure. In patients with PS, lobectomy seems to be a good therapeutic option.

Bronchial atresia is common to extralobar sequestration, intralobar sequestration, congenital cystic adenomatoid malformation, and lobar emphysema.Pediatr Dev Pathol. 2006 Sep-Oct;9(5):361-73.

Congenital cystic adenomatoid malformation (CCAM), intralobar sequestration (ILS), extralobar sequestration (ELS), and lobar emphysema (LE) are well-accepted entities; however, certain findings are common to all, particularly the parenchymal maldevelopment characterizing CCAM. Isolated reports have described bronchial atresia (BA) in some specimens in all 4 entities, but this finding has not been evaluated in a prospective manner. With the aid of a dissecting microscope, we prospectively examined 47 lung specimens resected during the past 4 years and submitted with the clinical impression of ELS (n=11), ILS (n=11), CCAM (n=20), LE (n=4), and airway-esophageal communication (n=1). Most lesions were detected by prenatal ultrasound and were resected during infancy. The clinical impression and pathologic findings were compared. Pathologic examination revealed atresia of a lobar, segmental, or subsegmental bronchus in 100% of ELS, 82% of ILS, 70% of CCAM, and 50% of LE (those clinically recognized to have BA or minor CCAM) cases. Parenchymal maldevelopment that characterizes CCAM was present in 100% of CCAM cases (as expected by definition) as well as in 91% of ELS, 91% of ILS, and 50% of LE (those with BA) cases. Bronchial atresia is present in all ELS, most ILS and CCAM, and some LE cases, and its detection is greatly enhanced with the dissecting microscope. Bronchial atresia and CCAM nearly always coexist. It may be that both have the same etiopathogenesis with anatomic differences accounted for by aberrant genetic programs or other insults, perhaps modified by time of onset or duration.

Intralobar pulmonary sequestration with high level of serum CEA; report of a case.Kyobu Geka. 2006 Jun;59(6):508-11.

We reported a case of intralobar pulmonary sequestration with a high level of the serum CEA. A 53-year-old woman whose chief complaint was cough was admitted to our hospital. Enhanced chest computed tomography (CT) revealed the mass in the left lower lung, lymph-nodes swelling, and the aberrant artery. Magnetic resonance angiography (MRA) conformed the aberrant artery from the descending aorta. The level of serum CEA elevated at 9.6 ng/ml. Left lower lobectomy was performed. A diagnosis of intralobar pulmonary sequestration (Pryce type II) was established in this case. Histopathologically, the peribronchial epithelial cells in pulmonary sequestration showed weak positive for anti-CEA monoclonal antibody. Postoperative course was uneventful and the serum CEA level was 3.5 ng/ml in the normal range at the postoperative 17th day.

Pulmonary sequestrations: from radiologic to preoperative diagnosis: 2 cases with review of the literature.Tunis Med. 2006 Feb;84(2):118-21.

Pulmonary sequestrations are defined by the presence of a non fonctional pulmonary parenchyma with an abnormal vascularisation. Their incidence ranges from 1.1% to 1.8% of all the malformations in the general population. Two types of sequestrations are described: Intralobar sequestrations: the most common, localised within a normal parenchyma. Extralobar sequestrations: totally separate from the lung with their own pleural covering. We report two cases of sequestrations. In the first case, the radioclinical presentation was strongly suggestive of this diagnosis in a 32-year old woman with recurrent hemoptysis, airspace opacity in the left retrocardiac region and a systemic vascularisation of this mass on tomodensitometry. Pathological studies after surgery confirmed the diagnosis of intralobar sequestration type I in the classification of PRYCE. In the second case a thoracoscopy performed on a 14-year-old boy who had a serohematic pleural effusion, revealed a left costodiaphragmatic mass. Surgical removal of this mass confirmed its extralobar pulmonary nature.

Spontaneous hemothorax: a rare but serious complication of intralobular pulmonary sequestration.Rev Pneumol Clin. 2006 Feb;62(1):30-3

Pulmonary sequestration is a rare congenital malformation characterized by a non-functional portion of pulmonary parenchyma devoid of any connection with the bronchial tree and pulmonary artery. If not identified antenatally or at birth, the sequestration may not be discovered until complications, mainly repeated infections, arise. Hemorrhage is another but much rarer complication which is generally severe. We report a new case of intralobular pulmonary sequestration revealed by hemoptysis then massive hemothroax with shock requiring emergency thoracotomy for hemostasis.

Extralobar pulmonary sequestration with aberrant lobulation of the lower lobe; report of a case.Kyobu Geka. 2005 Feb;58(2):161-4.

An adult case of extralobar pulmonary sequestration with aberrant lobulation of the right lower lobe is reported. A 32-year-old woman admitted to our hospital with a right intrathoracic tumor in the chest computed tomography (CT). Chest CT showed a mass lesion on the right diaphragm of a diameter 5 cm and abnormal fissure of the right lower lobe. Under the diagnosis of pulmonary sequestration without clearly thick vessels, video-assisted thoracoscopic surgery was performed. The mass existed between the right diaphragm and posterior lower lobe with a thin stalk, and the lower lobe had aberrant lobulation. The resected mass was histopathologically diagnosed as extralobar pulmonary sequestration.

Intralobar sequestration of the lung is a congenital anomaly: anatomopathological analysis of four cases diagnosed in fetal life.Pediatr Dev Pathol. 2003 Jul-Aug;6(4):314-21.

The origin of intralobar sequestration of the lung (ILS)-whether congenital or acquired--has often been controversial, since firm anatomical evidence of prenatal origin has been sparse. We describe four cases in which anomalous arterial supply from the aorta to abnormally echogenic lower lung lobes was demonstrated on routine antenatal ultrasound examination, and the diagnosis of ILS was subsequently confirmed by postmortem examination including bronchography of the fetuses at between 20 and 23 wk. One right-sided lesion was supplied from a branch of the coeliac axis, and three left-sided lesions were supplied from the thoracic aorta. In two cases, the arterial supply was shown to be multiple. All lesions were situated in the lower lobes. They showed a cystic transformation of the affected lung tissue which was histologically indistinguishable from cases diagnosed as congenital cystic adenomatoid lesion (CCAM) at the same gestational age, but clearly different from that seen in bronchial obstruction due to laryngeal stenosis at that age. Similar vascular lesions have been reported in otherwise normal lungs. The character of the anomalous arterial vessels is consistent with origin from the embryonic splanchnic plexus. The precise sequence of pathogenetic events is unclear but there appears to be a close relationship of this condition not only with CCAM but also with the condition of anomalous arterial supply to the lower lobe.