Congenital cystic adenomatoid malformation of the lung: indications and timing of surgery

Abstract

We review a single surgeon and surgical centre's experience with congenital cystic adenomatoid malformation of the lung (CCAML) in relation to clinical spectrum, operative experience, and postoperative course. A retrospective hospital record review was done on surgically treated cases of CCAML over a 10-year period, focusing on number with antenatal diagnosis, spectrum of postnatal presentation, type of surgery performed, and outcome. Forty-seven patients from birth to 14 years of age underwent surgery for CCAML. Antenatal diagnosis (ante) was made in 30 cases. Of these, 10 became symptomatic before surgery. Six of the 17 postnatally-diagnosed (pnd) cases were an asymptomatic incidental finding. Overall, 16 were symptomatic in the 1st year of life, and five were symptomatic beyond 1 year of age. Symptoms varied from respiratory distress (seven ante, six pnd) to chronic cough (three, and recurrent chest infection (three ante, two pnd). All preoperative diagnoses were confirmed with chest CT. Most patients (25) were operated on before 3 months of age. Eleven were operated on in the first 2 weeks of life as emergency surgery for respiratory distress. The most common lobe involved was the right upper lobe (16), and lobectomy was performed in 42 cases, segmentectomy in four, and pneumonectomy in one. Seventeen cases were extubated immediately postoperatively; 29 required postoperative ventilation overnight, and nine needed more prolonged ventilation. Early postoperative complications included pneumothorax (two), pleural effusion (one), and chylous effusion (one). Late complications included recurrence in three cases (all segmentectomy), who then subsequently underwent lobectomy. There was one death from respiratory failure. Because there is an increasing trend in the detection of asymptomatic antenatally-diagnosed CCAML, consideration of early surgical excision to prevent complications is suggested by our series. CT scanning is mandatory for postnatal evaluation because chest x-ray could be normal. Safe elective excision after 3 months is supported by our low morbidity and less need for postoperative ventilation. Lobectomy is the procedure of choice to prevent recurrence.

Malformações pulmonares congênitas

“…(4,35,36) A small number of patients present with a more aggressive form, which is represented by an extensive, rapidly growing lesion that can lead to hydrops fetalis caused by mediastinal shift, inferior vena cava obstruction, and cardiac compression, resulting in intrauterine death. (4,15,33) In such cases, drainage can be performed in utero by means of thoracentesis or thoracoamniotic shunt placement with cyst aspiration. (15,21) The combination of CCAM and certain other malformations, such as pulmonary sequestration, has been demonstrated in various studies, raising the hypothesis that type II CCAM and extralobar pulmonary sequestration have the same embryonic origin.…”

“…(29) According to one group of authors, CCAM probably results from arrested bronchial maturation and, at the same time, overgrowth of mesenchymal elements near gestational week 5 or 6. (4,20,33) Histologically, cartilage is absent, reflecting bronchial malformation; however, patients with CCAM present with small bronchial communications, which are very likely responsible for the infections, and hyperinflation. (27,33) Cystic formations are covered with columnar or cuboidal epithelium.…”

“…(15,26) In patients with CCAM, there is a broad spectrum of variation in terms of the evolution of the condition, which can be as severe as perinatal death (from hydrops fetalis or pulmonary hypoplasia) or as mild as asymptomatic lesions or spontaneous resolution of symptomatic lesions. (22,27,33,34) The most common symptoms are recurrent infections, (4,27,35) and there have been reports of malignant transformation (to of all CCAMs, (5,15,32,39) and can affect an entire lung or, more rarely, both lungs. (5) The cut-off surface of type III CCAM is firm and generally does not present with cystic lesions; when such lesions are present, they are no larger than 0.5 cm in diameter.…”

“…(5,15) Type III CCAM is the least common of the three, accounting for approximately 5-10% period, probably through a mechanism of apoptosis and lack of blood supply. (15,29,33,37) Patients with symptomatic CCAM can present with a history of recurrent pneumonia, cyanosis, respiratory difficulty, and pneumothorax. (15,28) In the prenatal phase, surgical intervention is still the best treatment option for the microcystic forms, which are associated with hydrops fetalis.…”

“…(21) The management of asymptomatic lesions is controversial; the exact length of the observation period, the type of resection, and the extent of the resection have yet to be determined. (5,8,15,33,38) However, most authors recommend resection because of the risk of infection or neoplastic transformation that such lesions carry, principally in cases of bronchioloalveolar carcinoma, myxosarcoma, pleuropulmonary blastoma, and rhabdomyosarcoma. (4,5,8,15,20,33,(36)(37)(38) Recently, one group of authors studied 129 cases of CCAM and found that the incidence of pleuropulmonary blastoma among the 54 patients who underwent surgery was 4%.…”