Limited Pulmonary
Resections for Congenital Cystic Adenomatoid Malformation of the Lung
By Steven
J. Mentzer,
Robert
M. Filler, and James
Phillips
Toronto, Ontario l Congenital cystic adenomatoid malformations (CAMS) are rare lung lesions characterized by the presence of a multicystic mass of pulmonary tissue. To clarify the surgical management of CAM of the lung, we reviewed our institutional experience with 34 patients with histologically documented CAM. Symptoms developed in the first 2 days of life in 20 patients; 14 patients developed symptoms a median of 69 days (range, 22 days to 15 years) after birth. A diagnosis of CAM was confirmed at thoracotomy in all patients. Four patients were treated with a limited pulmonary resection for disease confined to one lobe. Seven patients underwent a composite resection involving a lobectomy plus limited resection of the second lobe. One patient underwent pneumonectomy for a severely malformed lung. The remainder of the patients were treated with anatomic lobectomy. The only recurrence was a patient who had a partial cystectomy performed at the initial operation. We conclude that in the appropriate malformation subtype, limited pulmonary reactions can preserve lung tissue and may prevent subsequent complications of CAM. Copyrig& o 1992 by W.B. Saunders Company INDEX WORDS: tion.
Congenital
cystic adenomatoid
malforma-
C tion (CAM) is a rare lesion characterized ONGENITAL
cystic adenomatoid
malformaby the presence of a multicystic mass of pulmonary tissue.’ The malformation appears to be related to the abnormal development of lobar and segmental bronchi. These lung bud anomalies are believed to perturb the development of mature alveoli and result in a cystic mass of immature lung tissue.2-4 A clinically relevant feature of CAM is the communication between bronchiole-like structures and the cysts. Airway contiguity and the absence of supporting cartilage can result in significant air trapping in the newborn period. Expansion of the cyst and compression of surrounding lung may cause life-threatening respiratory distress. 5-9The malformed lung also has abnormal mucociliary clearance and immune func-
tion. In childhood and adolescence, the immature lung tissue is associated with recurrent infections.2J0-12 The potential for life-threatening complications has led to the suggestion that lobectomy or pneumonectomy should be the standard surgical management of CAM.6J3-16In many patients, however, the malformation may only involve an anatomic subdivision of a lobe. Limited resection, defined as a partial lobectomy or incomplete excision, may be an option in these patients. To determine the role of limited resections in the management of patients with CAM, we reviewed our experience with 34 patients. MATERIALS
AND
METHODS
The medical records of all patients presenting to the Hospital for Sick Children with a diagnosis of lung cyst from January 1, 1961 to July 1, 1989 were reviewed. The histopathology in 40 patients with lung cysts suggested a diagnosis of congenital CAM of the lung. Six patients were excluded because inflammatory changes precluded differentiation from postinflammatory pneumatocele. The remaining 34 patients form the basis of this report. The histology of the congenital CAM of the lung was classified according to Stocker et al.’ Briefly, type I CAM describes lungs with multiple cysts often greater than 1 cm. The walls are lined with ciliated epithelium with some smooth muscle and immature alveolus-like structures. Type II describes lungs with cysts less than 1 cm. The thin wall contains cylindrical to cuboidal epithelium with irregular smooth muscle bundles. Type III describes lungs with small cysts ( 3,000 g
Classification Type
1
II
Type
Ill
0
0
1
16
4
2
6
4
0
22
8
3
15
NOTE. The pathology of one case from 1973 could not be reexam-
85
ined for classification; therefore, the total number classified is 33.
Apgars* 27
7
21
>7
3
9
3
9
Polyhydramminos
*The Apgar score at 1 minute for one patient was not recorded; therefore, the scores reflect a total of 33 patients.
lems were polyhydramnios in 3 patients and prematurity (29 and 34 weeks) in 2 patients (Table 1). The median gestational age was 40 weeks (range, 29 to 41 weeks) and the mean birth weight was 3,385 + 537 g. Eleven patients were born with Apgar scores less than 8 at 1 minute. Four patients were born with other congenital anomalies: microcephaly and deafness, contralateral lung hypoplasia, pectus excavaturn, and extralobar sequestration. Presentation and Diagnosis of CAM
Symptoms developed in the first 2 days of life in 20 patients (Table 2). The most common signs were tachypnea, cyanosis, and chest wall retractions. One patient developed neonatal pneumonia. Chest radiography demonstrated a large cyst with mediastinal displacement in 15 of the 20 newborn patients. The clinical differential diagnoses included diaphragmatic hernia and congenital lobar emphysema. Sixteen of the 20 symptomatic newborn patients were diagnosed and treated within 4 days of developing symptoms, In 3 infants with persistent tachypnea the diagnosis was made at 74,131, and 158 days of age; one patient with recurrent pneumonias from birth was diagnosed at 5 years of age.
The remaining 14 patients developed symptoms a median of 69 days (range, 22 days to 15 years) after birth (Table 2). The presentation of these 14 patients included cough, tachypnea, pneumonia, and obstructive emphysema. Histopathology
All 34 patients had histopathologic findings consistent with CAM; in 33 patients, the histopathology was classified according to Stocker et al.’ The majority of cases were type I: 67% type I, 24% type II, and 9% type III. The 11 patients with type II and III CAM presented earlier (median, 4 days) than patients with type I CAM (median, 30 days). The patients with type I and type II CAM presented with similar signs and symptoms; the 3 patients with type III CAM presented with respiratory distress. Thoracotomy for CAM
The diagnosis of CAM was confirmed at thoracotomy in all 34 patients. Twenty-two patients underwent lobectomy. Seven patients underwent a composite resection involving lobectomy and limited resection of an involved second lobe. Two patients underwent segmentectomy and two patients had a partial cystectomy. One patient with involvement of the entire right lung required pneumonectomy (Tables 3 and 4). There were four postoperative deaths, all newborns who died of respiratory failure within 48 hours of surgery. One patient had type III CAM with severe
Table 2. Presentation of Patients With CAM Presentation
Symptoms*
Early (0 to 2 days) (n = 20)
Late
( > 2 weeks)
(n = 14)
Tachypnea
Table 4. Review of Pulmonary Resections for CAM
No. (%)
Mentzer
17 (85)
et al
Chest wall retraction
6 (40)
Cyanosis
4 (20)
Pneumonectomy
Pneumonia
1 (5)
Lobectomy
Tachypnea
4 129)
Segment/wedge*
Pneumonia
3 (21)
Cyst excision
Poor feeding
2 (14)
Total
Asymptomatic
2 (14)
Obstructive emphysema
1 (71
Cough
1 (7)
*The major symptoms leading to a diagnosis of CAM are listed. In several patients, more than one symptom major was present.
Wolf et aI8
Nishibayashi et aI6
1 (0)
3 (0)
22 (0)
22 (3)
15 (0)
9 (0)
4 (6)
3 (1)
2 (1) 34
29
2 (1) 20
NOTE. Number indicates the number of cases performed series;
( ) denotes
Lilly et al’9
2 (0) 2 in each
the number of local failures in each group.
*Refers to segmentectomy
or wedge resection of the involved lung
tissue. Seven patients had lobectomy plus limited resection of a second lobe.
1412
MENTZER, FILLER, AND PHILLIPS
hypoplasia of the contralateral lung; the other three deaths had type I (2) and type II (1) CAM. There were no perioperative complications in the remaining 30 patients. One patient who had undergone partial cystectomy recurred within 2 months of the initial operation. The patient underwent completion lobectomy without further problems. The other patient who had undergone partial cystectomy or “unroofing” of the cyst was asymptomatic 6 years after the initial operation. The median postoperative follow-up was 30 months. All surviving patients were active without respiratory symptoms except for one patient who subsequently developed asthma. DISCUSSION
The management of CAM of the lung has remained unclear because of the rarity of the malformation; approximately 200 cases have been reported in the literature. In this report, we describe our surgical management of an additional 34 cases of CAM. Eleven cases were treated with limited resection defined as a partial lobectomy or incomplete excision. There was one recurrence in a patient who had undergone a partial cystectomy. Stocker et al have speculated that the extent and histological types of CAM may correspond to perturbations at various times in developed.? For example, the embryonic respiratory tree begins to develop at day 26 with the elongation of the laryngotracheal groove and the formation of the major bronchi. By 35 to 45 days’ gestation, the segmental and subsegmental bronchi have formed. Prior to 35 days, an arrest in the developing lung bud would result in a “failure of maturation” of the entire lobe and a histological appearance typical of the type III malformation.2 In contrast, the histological maturation observed in type I malformations (eg, thick wall of smooth muscle, mucin glands, rudimentary cartilage plates) suggests a later developmental perturbation, perhaps as late as the seventh week of gestation.’ A developmental anomaly in the later stages of lung maturation would indicate possible involvement of a lobar subdivision. Whether the timing of the defect and the anatomic extent of the malformation are related remains unanswered by the present data. It is clear that type I malformations may involve multiple segments in more than one lobe. This was observed in six patients in the present series. Furthermore, there is at least one report of a type III malformation confined to a single atretic bronchopulmonary segment.18 These observations suggest that the extent and histological types of CAM are determined by multiple factors; the timing
of the developmental perturbation alone cannot predict the anatomy of the malformation. The extent of the malformation may not be easily assessed by radiographs or at operation. A large cyst may compress the surrounding lung tissue and complicate any anatomic assessment. The uncertainty regarding the extent of the malformation and a desire to preserve the uninvolved lung tissue has led to attempts at partial cystectomy or “unroofing” of the cyst. A potential advantage of “unroofing” the cyst is that it may decompress the underlying lung tissue and permit the reexpansion of the normal lung that would otherwise be resected. The disadvantage of “unroofing” the cyst is the 50% incidence of local recurrence (2 of 4 cases) (Table 4). We can speculate that the risk of local recurrences may be acceptable in circumstances when the CAM involves more than one lobe or when the function of the remaining lung is uncertain. The potential symptomatic recurrence of CAM suggests that the malformed lung should be completely removed at the initial operation. When the malformation involves a subdivision of a lobe, complete resection may involve a segmentectomy or wedge resection. Segmentectomy is performed by sequential division of the segmental vein, artery, and bronchus. As noted elsewhere,” the segmental vein can be absent in CAM. Of interest, the segmental bronchus was also absent in one case reported by Lilly et a119; nonetheless, there were no problems with differentiation of the pulmonary segments. With the increased used of stapling devices, wedge resections have become popular in pulmonary resections for neoplasms and congenital lung disease. Although the data are preliminary, we suspect that wedge resections removing all grossly involved lung tissue will prevent recurrent symptoms. We have not judged the risk of neoplasm2” or recurrence to be sufficient to warrant the routine intraoperative evaluation of microscopic margins. The advantage of a limited resection is the preservation of normally functioning lung tissue, especially when more than the lobe is involved. Frenckner and Freyschuss have reported follow-up pulmonary function results after lobectomy for CAM.21 The authors noted that, despite the removal of an average of 20% of the total lung volume, the spirometry values were approximately 90% of predicted. This finding indicates some functional compensation for the removed lung tissue. The relative importance of preserving lung tissue by limited resection depends on a judgment of the potential function of the remaining lung tissue and the risk of subsequent lung disease.
LIMITED PULMONARY
RESECTIONS FOR CAM
1413
REFERENCES 1. Becker MR, Schindera F, Maier WA: Congenital cystic adenomatoid malformation of the lung. Prog Pediatr Surg 21:112117,1987 2. Stocker JT, Madewell JE, Drake RM: Congenital cystic adenomatoid malformation of the lung: Classification and morphologic spectrum. Hum Path01 8:155-171, 1977 3. Olson JL. Mendelsohn G: Congenital cystic adenomatoid malformation of the lung. Arch Path01 Lab Med iO2:248-251,1978 4. Ostor AG, Fortune DW: Congenital cystic adenomatoid malformation of the lung. Am J Clin Path01 70:595-604, 1978 5. Walker J, Cudmore RE: Respiratory problems and cystic adenomatoid malformation of lung. Arch Dis Child 65:649-650, 1990 6. Nishibayashi SW, Andrassy RJ, Woolley MM: Congenital cystic adenomatoid malformation: A 30-year experience. J Pediatr Surg 16:704-706, 1981 7. Bale PM: Congenital cystic malformation of the lung. A form of congenital bronchiolar (“adenomatoid”) malformation. Am J Clin Path01 71:411-420, 1979 8. Wolf SA, Hertzler JH, Philippart Al: Cystic adenomatoid dysplasia of the lung. J Pediatr Surg 1.5:925-930,198O 9. Haller JA Jr, Golladay ES, Pickard LR, et al: Surgical management of lung bud anomalies: Lobar emphysema, bronchogenic cyst, cystic adenomatoid malformation, and intralobar pulmonary sequestration. Ann Thorac Surg 28:33-43,1979 10. Heij HA, Ekkelkamp S, Vos A: Diagnosis of congenital cystic adenomatoid malformation of the lung in newborn infants and children. Thorax 45:122-125. 1990 Il. Adzick NS, Harrison MR. Glick PL, et al: Fetal cystic adenomatoid malformation: Prenatal diagnosis and natural history. J Pediatr Surg 20~483-488,1985
12. Wexler HA, Dapena MV: Congenital cystic adenomatoid malformation. A report of three unusual cases. Radiology 126:737741,1978 13. Bailey PV, Tracy T Jr, Connors RH, et al: Congenital bronchopulmonary malformations. Diagnostic and therapeutic considerations. J Thorac Cardiovasc Surg 99:597-602, 1990 14. Wesley JR, Heidelberger KP, DiPietro MA, et al: Diagnosis and management of congenital cystic disease of the lung in children. J Pediatr Surg 21:202-207, 1986 15. Schneider JR, StCyr JA, Thompson TR, et al: The changing spectrum of cystic pulmonary lesions requiring surgical resection in infants. J Thorac Cardiovasc Surg 89:332-339, 1985 16. Halloran LG. Silverberg SG, Salzberg AM: Congenital cystic adenomatoid malformation of the lung. A surgical emergency. Arch Surg 104:715-719,1972 17. Harrison MR, Adzick NS, Jennings RW, et al: Antenatal intervention for congenital cystic adenomatoid malformation. Lancet 336:965-967, 1990 18. Cachia R, Sobonya RE: Congenital cystic adenomatoid malformation of the lung with bronchial atresia. Hum Path01 12:947-950, 1981 19. Lilly JR, Wesenberg RL, Shikes RH: Segmental lung resection in the first year of life. Ann Thorac Surg 22:16-22. 1976 20. Ueda K, Gruppo R, Unger F, et al: Rhabdomyosarcoma of lung arising in congenital cystic adenomatoid malformation. Cancer 40:383-388,1977 21. Frenckner B. Freyschuss U: Pulmonary function after lobectomy for congenital lobar emphysema and congenital cystic adenomatoid malformation. A follow-up study. Stand J Thorac Cardiovast Surg 16:293-298. 1982
Resections for Congenital Cystic Adenomatoid Malformation of the Lung
By Steven
J. Mentzer,
Robert
M. Filler, and James
Phillips
Toronto, Ontario l Congenital cystic adenomatoid malformations (CAMS) are rare lung lesions characterized by the presence of a multicystic mass of pulmonary tissue. To clarify the surgical management of CAM of the lung, we reviewed our institutional experience with 34 patients with histologically documented CAM. Symptoms developed in the first 2 days of life in 20 patients; 14 patients developed symptoms a median of 69 days (range, 22 days to 15 years) after birth. A diagnosis of CAM was confirmed at thoracotomy in all patients. Four patients were treated with a limited pulmonary resection for disease confined to one lobe. Seven patients underwent a composite resection involving a lobectomy plus limited resection of the second lobe. One patient underwent pneumonectomy for a severely malformed lung. The remainder of the patients were treated with anatomic lobectomy. The only recurrence was a patient who had a partial cystectomy performed at the initial operation. We conclude that in the appropriate malformation subtype, limited pulmonary reactions can preserve lung tissue and may prevent subsequent complications of CAM. Copyrig& o 1992 by W.B. Saunders Company INDEX WORDS: tion.
Congenital
cystic adenomatoid
malforma-
C tion (CAM) is a rare lesion characterized ONGENITAL
cystic adenomatoid
malformaby the presence of a multicystic mass of pulmonary tissue.’ The malformation appears to be related to the abnormal development of lobar and segmental bronchi. These lung bud anomalies are believed to perturb the development of mature alveoli and result in a cystic mass of immature lung tissue.2-4 A clinically relevant feature of CAM is the communication between bronchiole-like structures and the cysts. Airway contiguity and the absence of supporting cartilage can result in significant air trapping in the newborn period. Expansion of the cyst and compression of surrounding lung may cause life-threatening respiratory distress. 5-9The malformed lung also has abnormal mucociliary clearance and immune func-
tion. In childhood and adolescence, the immature lung tissue is associated with recurrent infections.2J0-12 The potential for life-threatening complications has led to the suggestion that lobectomy or pneumonectomy should be the standard surgical management of CAM.6J3-16In many patients, however, the malformation may only involve an anatomic subdivision of a lobe. Limited resection, defined as a partial lobectomy or incomplete excision, may be an option in these patients. To determine the role of limited resections in the management of patients with CAM, we reviewed our experience with 34 patients. MATERIALS
AND
METHODS
The medical records of all patients presenting to the Hospital for Sick Children with a diagnosis of lung cyst from January 1, 1961 to July 1, 1989 were reviewed. The histopathology in 40 patients with lung cysts suggested a diagnosis of congenital CAM of the lung. Six patients were excluded because inflammatory changes precluded differentiation from postinflammatory pneumatocele. The remaining 34 patients form the basis of this report. The histology of the congenital CAM of the lung was classified according to Stocker et al.’ Briefly, type I CAM describes lungs with multiple cysts often greater than 1 cm. The walls are lined with ciliated epithelium with some smooth muscle and immature alveolus-like structures. Type II describes lungs with cysts less than 1 cm. The thin wall contains cylindrical to cuboidal epithelium with irregular smooth muscle bundles. Type III describes lungs with small cysts ( 3,000 g
Classification Type
1
II
Type
Ill
0
0
1
16
4
2
6
4
0
22
8
3
15
NOTE. The pathology of one case from 1973 could not be reexam-
85
ined for classification; therefore, the total number classified is 33.
Apgars* 27
7
21
>7
3
9
3
9
Polyhydramminos
*The Apgar score at 1 minute for one patient was not recorded; therefore, the scores reflect a total of 33 patients.
lems were polyhydramnios in 3 patients and prematurity (29 and 34 weeks) in 2 patients (Table 1). The median gestational age was 40 weeks (range, 29 to 41 weeks) and the mean birth weight was 3,385 + 537 g. Eleven patients were born with Apgar scores less than 8 at 1 minute. Four patients were born with other congenital anomalies: microcephaly and deafness, contralateral lung hypoplasia, pectus excavaturn, and extralobar sequestration. Presentation and Diagnosis of CAM
Symptoms developed in the first 2 days of life in 20 patients (Table 2). The most common signs were tachypnea, cyanosis, and chest wall retractions. One patient developed neonatal pneumonia. Chest radiography demonstrated a large cyst with mediastinal displacement in 15 of the 20 newborn patients. The clinical differential diagnoses included diaphragmatic hernia and congenital lobar emphysema. Sixteen of the 20 symptomatic newborn patients were diagnosed and treated within 4 days of developing symptoms, In 3 infants with persistent tachypnea the diagnosis was made at 74,131, and 158 days of age; one patient with recurrent pneumonias from birth was diagnosed at 5 years of age.
The remaining 14 patients developed symptoms a median of 69 days (range, 22 days to 15 years) after birth (Table 2). The presentation of these 14 patients included cough, tachypnea, pneumonia, and obstructive emphysema. Histopathology
All 34 patients had histopathologic findings consistent with CAM; in 33 patients, the histopathology was classified according to Stocker et al.’ The majority of cases were type I: 67% type I, 24% type II, and 9% type III. The 11 patients with type II and III CAM presented earlier (median, 4 days) than patients with type I CAM (median, 30 days). The patients with type I and type II CAM presented with similar signs and symptoms; the 3 patients with type III CAM presented with respiratory distress. Thoracotomy for CAM
The diagnosis of CAM was confirmed at thoracotomy in all 34 patients. Twenty-two patients underwent lobectomy. Seven patients underwent a composite resection involving lobectomy and limited resection of an involved second lobe. Two patients underwent segmentectomy and two patients had a partial cystectomy. One patient with involvement of the entire right lung required pneumonectomy (Tables 3 and 4). There were four postoperative deaths, all newborns who died of respiratory failure within 48 hours of surgery. One patient had type III CAM with severe
Table 2. Presentation of Patients With CAM Presentation
Symptoms*
Early (0 to 2 days) (n = 20)
Late
( > 2 weeks)
(n = 14)
Tachypnea
Table 4. Review of Pulmonary Resections for CAM
No. (%)
Mentzer
17 (85)
et al
Chest wall retraction
6 (40)
Cyanosis
4 (20)
Pneumonectomy
Pneumonia
1 (5)
Lobectomy
Tachypnea
4 129)
Segment/wedge*
Pneumonia
3 (21)
Cyst excision
Poor feeding
2 (14)
Total
Asymptomatic
2 (14)
Obstructive emphysema
1 (71
Cough
1 (7)
*The major symptoms leading to a diagnosis of CAM are listed. In several patients, more than one symptom major was present.
Wolf et aI8
Nishibayashi et aI6
1 (0)
3 (0)
22 (0)
22 (3)
15 (0)
9 (0)
4 (6)
3 (1)
2 (1) 34
29
2 (1) 20
NOTE. Number indicates the number of cases performed series;
( ) denotes
Lilly et al’9
2 (0) 2 in each
the number of local failures in each group.
*Refers to segmentectomy
or wedge resection of the involved lung
tissue. Seven patients had lobectomy plus limited resection of a second lobe.
1412
MENTZER, FILLER, AND PHILLIPS
hypoplasia of the contralateral lung; the other three deaths had type I (2) and type II (1) CAM. There were no perioperative complications in the remaining 30 patients. One patient who had undergone partial cystectomy recurred within 2 months of the initial operation. The patient underwent completion lobectomy without further problems. The other patient who had undergone partial cystectomy or “unroofing” of the cyst was asymptomatic 6 years after the initial operation. The median postoperative follow-up was 30 months. All surviving patients were active without respiratory symptoms except for one patient who subsequently developed asthma. DISCUSSION
The management of CAM of the lung has remained unclear because of the rarity of the malformation; approximately 200 cases have been reported in the literature. In this report, we describe our surgical management of an additional 34 cases of CAM. Eleven cases were treated with limited resection defined as a partial lobectomy or incomplete excision. There was one recurrence in a patient who had undergone a partial cystectomy. Stocker et al have speculated that the extent and histological types of CAM may correspond to perturbations at various times in developed.? For example, the embryonic respiratory tree begins to develop at day 26 with the elongation of the laryngotracheal groove and the formation of the major bronchi. By 35 to 45 days’ gestation, the segmental and subsegmental bronchi have formed. Prior to 35 days, an arrest in the developing lung bud would result in a “failure of maturation” of the entire lobe and a histological appearance typical of the type III malformation.2 In contrast, the histological maturation observed in type I malformations (eg, thick wall of smooth muscle, mucin glands, rudimentary cartilage plates) suggests a later developmental perturbation, perhaps as late as the seventh week of gestation.’ A developmental anomaly in the later stages of lung maturation would indicate possible involvement of a lobar subdivision. Whether the timing of the defect and the anatomic extent of the malformation are related remains unanswered by the present data. It is clear that type I malformations may involve multiple segments in more than one lobe. This was observed in six patients in the present series. Furthermore, there is at least one report of a type III malformation confined to a single atretic bronchopulmonary segment.18 These observations suggest that the extent and histological types of CAM are determined by multiple factors; the timing
of the developmental perturbation alone cannot predict the anatomy of the malformation. The extent of the malformation may not be easily assessed by radiographs or at operation. A large cyst may compress the surrounding lung tissue and complicate any anatomic assessment. The uncertainty regarding the extent of the malformation and a desire to preserve the uninvolved lung tissue has led to attempts at partial cystectomy or “unroofing” of the cyst. A potential advantage of “unroofing” the cyst is that it may decompress the underlying lung tissue and permit the reexpansion of the normal lung that would otherwise be resected. The disadvantage of “unroofing” the cyst is the 50% incidence of local recurrence (2 of 4 cases) (Table 4). We can speculate that the risk of local recurrences may be acceptable in circumstances when the CAM involves more than one lobe or when the function of the remaining lung is uncertain. The potential symptomatic recurrence of CAM suggests that the malformed lung should be completely removed at the initial operation. When the malformation involves a subdivision of a lobe, complete resection may involve a segmentectomy or wedge resection. Segmentectomy is performed by sequential division of the segmental vein, artery, and bronchus. As noted elsewhere,” the segmental vein can be absent in CAM. Of interest, the segmental bronchus was also absent in one case reported by Lilly et a119; nonetheless, there were no problems with differentiation of the pulmonary segments. With the increased used of stapling devices, wedge resections have become popular in pulmonary resections for neoplasms and congenital lung disease. Although the data are preliminary, we suspect that wedge resections removing all grossly involved lung tissue will prevent recurrent symptoms. We have not judged the risk of neoplasm2” or recurrence to be sufficient to warrant the routine intraoperative evaluation of microscopic margins. The advantage of a limited resection is the preservation of normally functioning lung tissue, especially when more than the lobe is involved. Frenckner and Freyschuss have reported follow-up pulmonary function results after lobectomy for CAM.21 The authors noted that, despite the removal of an average of 20% of the total lung volume, the spirometry values were approximately 90% of predicted. This finding indicates some functional compensation for the removed lung tissue. The relative importance of preserving lung tissue by limited resection depends on a judgment of the potential function of the remaining lung tissue and the risk of subsequent lung disease.
LIMITED PULMONARY
RESECTIONS FOR CAM
1413
REFERENCES 1. Becker MR, Schindera F, Maier WA: Congenital cystic adenomatoid malformation of the lung. Prog Pediatr Surg 21:112117,1987 2. Stocker JT, Madewell JE, Drake RM: Congenital cystic adenomatoid malformation of the lung: Classification and morphologic spectrum. Hum Path01 8:155-171, 1977 3. Olson JL. Mendelsohn G: Congenital cystic adenomatoid malformation of the lung. Arch Path01 Lab Med iO2:248-251,1978 4. Ostor AG, Fortune DW: Congenital cystic adenomatoid malformation of the lung. Am J Clin Path01 70:595-604, 1978 5. Walker J, Cudmore RE: Respiratory problems and cystic adenomatoid malformation of lung. Arch Dis Child 65:649-650, 1990 6. Nishibayashi SW, Andrassy RJ, Woolley MM: Congenital cystic adenomatoid malformation: A 30-year experience. J Pediatr Surg 16:704-706, 1981 7. Bale PM: Congenital cystic malformation of the lung. A form of congenital bronchiolar (“adenomatoid”) malformation. Am J Clin Path01 71:411-420, 1979 8. Wolf SA, Hertzler JH, Philippart Al: Cystic adenomatoid dysplasia of the lung. J Pediatr Surg 1.5:925-930,198O 9. Haller JA Jr, Golladay ES, Pickard LR, et al: Surgical management of lung bud anomalies: Lobar emphysema, bronchogenic cyst, cystic adenomatoid malformation, and intralobar pulmonary sequestration. Ann Thorac Surg 28:33-43,1979 10. Heij HA, Ekkelkamp S, Vos A: Diagnosis of congenital cystic adenomatoid malformation of the lung in newborn infants and children. Thorax 45:122-125. 1990 Il. Adzick NS, Harrison MR. Glick PL, et al: Fetal cystic adenomatoid malformation: Prenatal diagnosis and natural history. J Pediatr Surg 20~483-488,1985
12. Wexler HA, Dapena MV: Congenital cystic adenomatoid malformation. A report of three unusual cases. Radiology 126:737741,1978 13. Bailey PV, Tracy T Jr, Connors RH, et al: Congenital bronchopulmonary malformations. Diagnostic and therapeutic considerations. J Thorac Cardiovasc Surg 99:597-602, 1990 14. Wesley JR, Heidelberger KP, DiPietro MA, et al: Diagnosis and management of congenital cystic disease of the lung in children. J Pediatr Surg 21:202-207, 1986 15. Schneider JR, StCyr JA, Thompson TR, et al: The changing spectrum of cystic pulmonary lesions requiring surgical resection in infants. J Thorac Cardiovasc Surg 89:332-339, 1985 16. Halloran LG. Silverberg SG, Salzberg AM: Congenital cystic adenomatoid malformation of the lung. A surgical emergency. Arch Surg 104:715-719,1972 17. Harrison MR, Adzick NS, Jennings RW, et al: Antenatal intervention for congenital cystic adenomatoid malformation. Lancet 336:965-967, 1990 18. Cachia R, Sobonya RE: Congenital cystic adenomatoid malformation of the lung with bronchial atresia. Hum Path01 12:947-950, 1981 19. Lilly JR, Wesenberg RL, Shikes RH: Segmental lung resection in the first year of life. Ann Thorac Surg 22:16-22. 1976 20. Ueda K, Gruppo R, Unger F, et al: Rhabdomyosarcoma of lung arising in congenital cystic adenomatoid malformation. Cancer 40:383-388,1977 21. Frenckner B. Freyschuss U: Pulmonary function after lobectomy for congenital lobar emphysema and congenital cystic adenomatoid malformation. A follow-up study. Stand J Thorac Cardiovast Surg 16:293-298. 1982
