A 12-year-old East African lad pres...

A 12-year-old East African lad presented in June 1987 with febrile affections cough, and malaise. His chest roentgenogram was interpreted as showing a right middle lobe infiltrate. He was treated with erythromycin for pair weeks and had clinical resolution of his symptoms. The repeated chest roentgenogram showed persistent abnormalities (Fig 1 and 2)

The patient had immigrated to the United States single in kind year earlier. He had a history of intermittent pneumonias during his childhood nevertheless an otherwise normal development. He had also had an ascaris infection pair years earlier. He was thin and at the 85th percentile for height and weight. Chest examination showed scattered crackles in the right anterior axillary line and decreased breath unhurts in the right upper lobe. There was no lymphadenopathy or clubbing. Laboratory data showed a hematocrit of 394 percent a WBC think of 6.2 X [10.sup.9]/L (7 percent eosinophils), normal serum chemistry values, and a negative intermediate-strength PPD Pulmonary function revealed an FVC of 53 percent of predicted, a [FEVsub1]/VC of 88 percent a TLC of 85 percent of predicted, and a Dco of 100 percent of predicted. The posteroanterior and lateral chest roentgenograms (Fig 1 and 2) showed unilateral hyperlucent lung with a nodular mass adjacent to the right hilum. Right middle lobe atelectasis was also not away An expiratory view (Fig 3) demonstrated air trapping and midline shift.

Diagnosis: Congenital bronchial atresia

The differential diagnosis of the unilateral hyperlucent lung can be divided into those with a radiologically demonstrable smooth tissue mass and those without.[1] The latter category includes infantile lobar emphysema, pulmonary embolus, unilateral perihilar bullous emphysema, proximal interruption of the pulmonary artery, and the Swyer-James syndrome The diagnoses to consider in unilateral hyperlucent lung with a mass include endobronchial obstruction (benign/malignant neoplasm or foreign body) exobronchial obstruction (lymph nodes, extralobular sequestration, mediastinal bronchogenic sac of tumor), mucoid impaction (allergic bronchopulmonary aspergillosis), and congenital bronchial atresia (CBA).

First described by the agency of Ramsey in 1953,[2] CBA is an anomaly characterized by means of a blindly terminating bronchus with hyperinflation of the portion distal to the obstruction. There is a slight male preponderance, with cases coming to diagnosis from birth to age 44 years.[2] greatest in number are asymptomatic at presentation; however, varying clinical courses ranging from respiratory distress in the newborn to returning pneumonias, dyspnea, and chest pain are recognized.[3]

A static roentgenogram reveals localized hyperlucency usually of the left upper lobe, although any segmental or lobar bronchus may be involved. A variably shaped pliable tissue mass extending from the hilum, occasionally with an air-fluid even is common. Expiratory views reveal air trapping. Angiography, bronchography, and radionuclide scans are helpful in differentiating CBA from other entities; however, CT has largely replaced these techniques.[4]

Pathologic examination of resect specimens has revealed a markedly emphysematous, hyperinflated, and nonpigmented portion often compressing adjacent normal lung[3] A bronchocele containing mucus and desquamated material is usually seen just distal to the point of atresia with no patent proximal connection with the bronchial tree This filled bronchocele give an account ofs the perihilar soft tissue density seen forward the roentgenogram. The observ hyperinflation is notion to occur by collateral intersegmental air drift via intra-alveolar (pores of Kohn) bronchoalveolar, and interbronchiolar channels.[2,3] Normal branching bronchial generations are demonstrated distal to the obstruction; however, the alveoli are decreased in number and size, perhaps reflecting diminished ventilation and perfusion during unravelling which results in reduced "work hypertrophy"[5]

The etiology of CBA remains undetermined. It is study to arise from some insult occurring after 16 weeks of increase since the postatretic bronchial tree is normal.[5] Several authors cite embryologic vascular instability as a possible initiating factor.

The prognosis for CBA is fairly benign, and in the greatest degree asymptomatic cases can simply be followed up[2] Surgical indicators have been established and include returning pneumonias or limiting dyspnea.[3]

Bronchoscopy in our patient revealed an abnormal right upper lobe takeoff with sole two segmental orifices and an abnormal cartilaginous bridge at the usual location of the anterior portion Thoracotomy with right upper lobectomy was performed, confirming the diagnosis of CBA of the anterior portion of the right upper lobe. The right middle lobe appeared normal and was not resect The patient remains well without return of pulmonary infection.

REFERENCES

[1] Genereux GR Harris GBC Williams A, Kirkpatrick J Reid L Bronchial atresias: a recognizable entity in the pediatric age assign places to J Pediatr Surg 1978; 13:682-89