Fig 12.20 Extralobar sequestration. Photograph of the cut surface of a suprarenal mass, clinically thought to be neuroblastoma, from a 4-month-old girl. The specimen is a pyramidal mass 4.5cm in maximum dimension and has a spongy cut surface.

Fig 12.21 Extralobar sequestration. Photomicrograph of the same specimen as Fig 12.20. The lung shows cystic change resembling CPAM type 2. There is some fresh traumatic hemorrhage. There was also chronic inflammation. It contained striated muscle fibers. Cartilage-containing bronchi were also present.

Fig 12.22 Intralobar sequestration. Left lower lobe from a one-year-old boy. The site is typical for intralobar sequestration. A large elastic artery enters the medial aspect of the specimen at the medial diaphragmatic surface. The cut surface showed cystic change.

Fig 12.23 Intralobar sequestration. Photomicrograph of specimen Fig 12.22. There is extensive fresh hemorrhage and there is active inflammation. The bronchi and bronchioles are distended by purulent material. The arteries appear thick-walled.

Fig 12.24 Intralobar sequestration. Photomicrograph of the peripheral vasculature in the same case as Figs 12.22 and 12.23. There is muscularization of the intra-acinar arteries and there is also intimal cellular proliferation, both features indicating pulmonary arterial hypertension, presumably from exposure to the systemic arterial pressure of the anomalous systemic arterial supply. (EVG)

Fig 12.25 Congenital lobar overinflation. Resection of a hyperlucent left upper lobe in a 30-day-old female infant. The roughly triangular overdistended area of lung is evident to the right of the picture. The cut surface shows a few tiny apparent cysts beneath the pleura.

Fig 12.26 Congenital lobar overinflation. Photomicrograph from specimen in Fig 12.25. There is overdistension of alveoli and alveolar ducts (to four to five times the normal diameter). The magnitude of the distension may not be evident until compared with an age-matched control section of lung. Interstitial emphysema was also evident but no other abnormality. No bronchial obstruction could be demonstrated. (H&E)

Fig 12.27 Bronchogenic cyst. Intrapulmonary unilocular cyst with a thin wall and some obstructive changes in the surrounding lung.

Fig 12.28 Bronchogenic cyst. Photomicrograph of a section through the wall of a pulmonary bronchogenic cyst to demonstrate the respiratory epithelial lining and the presence of mucinous glands. No smooth muscle is evident in this field. Crucially for the diagnosis, hyaline cartilage is also present. In the absence of cartilage these cysts are better termed foregut cysts.

Fig 12.29 Pulmonary hydatid cyst. 9-year-old child with lung cyst. The photograph shows the excised lung tissue. The lung is consolidated and shows a cyst with a thick inflammatory grey wall. The lining white membrane (exocyst) has shrunken away from the wall. The contents are mucinous.

Fig 12.30 Pulmonary hydatid cyst. Photomicrograph of the lining membrane (exocyst) from a pulmonary hydatid cyst. The laminated eosinophilic nature of the specimen is very characteristic of hydatid disease. No scolices were identified in this case. There was a prominent eosinophilic infiltrate in the surrounding lung.

Fig 12.31 Pneumatocele. Right lower lobe of lung from a 6-year-old boy who developed pneumatocele after group A Streptococcal pneumonia. He developed broncho-pleural fistula, pneumothorax and pleuritis, necessitating surgical intervention. The probe extends from bottom left through the fistula into the incomplete lung cavity.

Fig 12.32 Persistent interstitial pulmonary emphysema. Teenage girl with congenital myopathy and recurrent pneumathoraces. Bullectomy right apex. Photomicrograph showing multiple irregular spaces lined by multinucleated foreign body giant cells. The reaction is typical of that which occurs with persistent air in the tissues.