A Rare Intrapericardial
Mass in a Neonate
By A.H. Hayashi, D.R. McLean, A. Peliowski, A.J. Tierney, and N.N. Finer Edmonton, Alberta 0 We describe a rare case of a neonate born with an intrapericardial mass composed of extralobar pulmonary sequestration and a cyst of bronchogenic origin. After an uneventful delivery, this full-term newborn was noted to be grunting and indrawing. He remained tachypneic despite adequate management for bilateral pneumothoraces. Diagnostic studies showed a 3 x 3 x 4 cm diameter cystic lesion in the anterior mediastinum causing posterior-lateral displacement of the superior vena cava. The heart itself was structurally normal. Bronchoscopy and esophagoscopy failed to detect any structural abnormalities. At 3 weeks of age, sternotomy and resection of the lesion was performed. The mass was clearly intrapericardial and consisted of sequestrated pulmonary tissue with a unilocular mucus filled bronchogenic cyst. Small systemic tributaries fed the lesion from the posterior-superior aspect. There was no connection with the heart or great vessels. Postoperative recovery was uneventful. Copyright o 1992 by W.B. Saunders Company INDEX WORDS: Pulmonary sequestration, chogenic cyst; intrapericardial mass.
extralobar;
bron-
I
NTRAPERICARDIAL masses are very uncommon lesions. We have recently encountered a neonate born with a complex intrapericardial mass of bronchopulmonary origin. CASE REPORT This 4.25-kg native Canadian boy was born at term to a 39year-old mother (gravida 3, para 3). The pregnancy was uneventful. No prenatal ultrasound was performed. The Apgars were 5 and 9 following spontaneous vaginal delivery; however, he was grunting and indrawing. He initially settled with oxygen, but became dusky after his first feed. A chest x-ray showed bilateral pneumothoraces that were subsequently managed with bilateral chest drains and he was intubated and transported to our facility. He arrived stable on 60% oxygen and was easily extubed later that day. A repeat chest x-ray demonstrated bilateral upper lobe atelectasis. Mediastinal structures were positioned in the midline. An echocardiogram showed a 3 x 3 x 4 cm solitary cystic mass in the anterior-superior mediastinum. A thoracic computed tomography (CT) scan confirmed these findings and also demonstrated posteriorlateral displacement of the superior vena cava. No structural abnormality was identified at bronchoscopy and esophagoscopy. Despite being hemodynamically stable, tachypnea remained a constant feature. At 3 weeks of age, sternotomy and resection of the lesion was performed. The mass was clearly intrapericardial and anterior to the right atrium and great vessels. No pericardial defect was present. Twenty milliliters of clear yellow pericardial fluid was suctioned. The mass was attached along the superior pericardium to the distal trachea by a solid fibrocartilagenous stalk and fed by several systemic tributaries posterior-laterally. There was no connection with the heart or great vessels. The mass was dark red, pyramidal in shape, with a smooth glistening surface and had the consistency of liver. A large 3.5-cm diameter solitary mucus-filled cyst was eccentrically located along the superior JournalofPediafric Surgery, Vol27, No 10 (October), 1992: pp 1361-1363
aspect of this mass. The baby’s postoperative recovery was uneventful.
Pathologic Examination Gross examination showed a purple, pyramid-shaped specimen invested in pleura weighing 30 g and measuring 5.0 x 3.5 x 3.0 cm. Cut surfaces showed a stalk of cartilaginous tissue present at the apex followed by a 3.5-cm diameter cyst with a thin trabeculated wall containing opaque white mucoid material. Lung parenchyma was located toward the base of the lesion (Fig 1). Microscopic examination showed the cyst to be lined by pseudostratified respiratory epithelium (Fig 2). Large plates of cartilage and mucous glands were identified toward the stalk suggestive of a bronchus. Progressive loss of cartilage was identified toward the body of the cyst. The sequestrated component showed intrapulmonary bronchi, a mild proliferation of bronchioles, and slight dilatation of alveoli (Fig 3). There was no evidence of gastrointestinal tissue nor were there ectodermal elements to suggest a teratoma. DISCUSSION
Intrapericardial masses are uncommon congenital anomalies; intrapericardial sequestrations are particularly rare. Teratomas are the most common tumor in this location in the pediatric age group.’ Deenadayalu et al reviewed 31 intrapericardial teratomas and 21 intrapericardial bronchogenic cystsS2 They determined that some previous cases of bronchogenic cysts were misinterpreted and reported as being teratomas. Only two reports of intrapericardial pulmonary sequestrations have been reported.3,4 This number may actually be greater since some intrapericardial sequestrations may have also been misclassified as teratoma or “teratoid” tumors.3 To our knowledge, our case represents the first intrapericardial pulmonary sequestration associated with a bronchogenic cyst. Pulmonary sequestration and bronchogenic cysts constitute part of a spectrum of congenital bronchopulmonary malformations. As illustrated in this case, and as reported by others, bronchogenic cysts may coexist with sequestrations.5-s Many theories have been proposed to explain the etiology of such anoma-
From the Departments of Surgery, Pathology and Neonatology, Royal Alexandra Hospital, Edmonton, Alberta. Presented at the 23rd Annual Meeting of the Canadian Association of Paediatric Surgeons, Quebec City, Quebec, September 19-22. 1991. Address reprint requests to A.H. Hayashi, MD, Allin Clinic, Department of Surgery, 10155-120 St, Edmonton, Alberta T5K U2, Canada. Copyright o 1992 by WB. Saunders Company 0022-346819212710-0030$03.0010 1361
1362
HAYASHI ET AL
i
Fig 2. The proximal portion of the cyst shows large plates of cartilage with mucous glands. The mucosa (upper left) consists of ciliated pseudostratified respiratory epithelium.
lies. Most support a unified concept where bronchopulmonary malformations arise from abnormal lung bud development.6%9-i1 The embryogenesis of intrapericardial bronchopulmonary malformations can be explained as follows. The lung bud develops at the caudal end of the laryngotracheal tube and grows into the pericardioperitoneal canals (primitive pleural cavities) during the 5th week of development.i2 The primitive heart and lungs at this stage, share a common coelomic cavity and are in close proximity.2 The pleuropericardial membranes begin to appear laterally as ridges of mesenchyme at about the same time.12 By the 6th or 7th week, the pleuropericardial membranes fuse in the midline creating separate pleural and pericardial cavities.12 In the present infant, the separation of lung bud tissue and inclusion within the-pericardial sac must have taken place during this time interval. Timing of embryologic alterations to the lung bud
INTRAPERICARDIAL
1363
MASS IN A NEONATE
during this period may determine the type of intrapericardial lesion. Bronchogenic cysts are believed to originate early in lung bud development, before the bronchi are formed.” Extralobar sequestrations are thought to develop later in time,1°J3 perhaps near the time of pericardial closure, from a supernumerary bud arising caudal to the normally located lung bud. This reasoning may explain why the incidence of intrapericardial bronchogenic cysts significantly outnumber sequestrations. Approximately 50% of patients with intrapericardial tumors present during infancy.2 All infants are symptomatic with signs of respiratory distress or cardiac tamponade. 2,4Echocardiogram and CT scans are sufficient to establish the diagnosis. Once the
diagnosis is determined, management is surgical. This is best approached through a midline sternotomy. Tumor adherence around the root of the aorta has been described and should lead one to proceed in this area with caution.? We have presented a unique case in that the mass described was intrapericardial in location, and consisted of a combination of sequestered lung and bronchogenic cyst. The differential diagnosis of these rare intrapericardial masses in the pediatric age group includes teratomas, hemangiomas, fibromas, and pericardial cysts.r4 ACKNOWLEDGMENT Special thanks to Lisa Hassell for preparation of this manuscript.
REFERENCES 1. Dehner LP: Mediastinum, lungs, and cardiovascular system, in Pediatric Surgical Pathology (ed 2). Baltimore, MD, Williams & Wilkins, 1987, pp 229-333 2. Deenadayalu RP, Tuuri D, Dewall RA, et al: Intrapericardial teratoma and bronchogenic cyst. Review of literature and report of successful surgery in infant with intrapericardial teratoma. J Thorac Cardiovasc Surg 67~945952.1974 3. Baar HS, D’Abreu AL: Duplications of the foregut. Br J Surg 37:220-230,1949 4. Levi A, Findler M, Dolfin T, et al: Intrapericardial extralobar pulmonary sequestration in a neonate. Chest 98:1014-1015, 1990 5. Stocker JT, Kagan-Hallet K: Extralobar pulmonary sequestration. Am J Clin Path01 72:917-925, 1979 6. Demos NJ, Teresi A: Congenital lung malformations. A unified concept and a case report. J Thorac Cardiovasc Surg 70:260-264, 1975 7. Ramenofsky ML, Leape LL, McCauley RGK: Bronchogenic cyst. J Pediatr Surg 14:219-224,1979 8. Gerle RD, Jaretzki A, Ashley CA, et al: Congenital broncho-
pulmonary foregut malformation. Pulmonary sequestration communicating with the gastrointestinal tract. N Engl J Med 278:14131419.1968 9. Luck SR, Reynolds M, Raffensperger JG: Congenital bronchopulmonary malformations. Curr Prob Surg 23:246-314, 1986 10. Heithoff KB, Sane SM, Williams HJ, et al: Bronchopulmonary foregut malformations. A unifying etiological concept. AJR Am J Roentgen01 126:46-55, 1976 11. Sieber WK: Lung cysts, sequestration, and bronchopulmonary dysplasia, in Welch KJ, Randolph JG, Ravitch MM, et al (eds): Pediatric Surgery (ed 4). Chicago, IL, Year Book. 1986, pp 645-654 12. Moore KL: The Developing Human (ed 3). Philadelphia, PA, Saunders, 1982 13. Bailey PV. Tracy T, Connors RH, et al: Congenitaly bronchopulmonary malformations. Diagnostic and therapeutic considerations. J Thorac Cardiovasc Surg 99:597-603, 1990 14. McAllister HA: Primary tumors and cysts of the heart and pericardium. Curr Prob Cardiol4:8-27,1979
Mass in a Neonate
By A.H. Hayashi, D.R. McLean, A. Peliowski, A.J. Tierney, and N.N. Finer Edmonton, Alberta 0 We describe a rare case of a neonate born with an intrapericardial mass composed of extralobar pulmonary sequestration and a cyst of bronchogenic origin. After an uneventful delivery, this full-term newborn was noted to be grunting and indrawing. He remained tachypneic despite adequate management for bilateral pneumothoraces. Diagnostic studies showed a 3 x 3 x 4 cm diameter cystic lesion in the anterior mediastinum causing posterior-lateral displacement of the superior vena cava. The heart itself was structurally normal. Bronchoscopy and esophagoscopy failed to detect any structural abnormalities. At 3 weeks of age, sternotomy and resection of the lesion was performed. The mass was clearly intrapericardial and consisted of sequestrated pulmonary tissue with a unilocular mucus filled bronchogenic cyst. Small systemic tributaries fed the lesion from the posterior-superior aspect. There was no connection with the heart or great vessels. Postoperative recovery was uneventful. Copyright o 1992 by W.B. Saunders Company INDEX WORDS: Pulmonary sequestration, chogenic cyst; intrapericardial mass.
extralobar;
bron-
I
NTRAPERICARDIAL masses are very uncommon lesions. We have recently encountered a neonate born with a complex intrapericardial mass of bronchopulmonary origin. CASE REPORT This 4.25-kg native Canadian boy was born at term to a 39year-old mother (gravida 3, para 3). The pregnancy was uneventful. No prenatal ultrasound was performed. The Apgars were 5 and 9 following spontaneous vaginal delivery; however, he was grunting and indrawing. He initially settled with oxygen, but became dusky after his first feed. A chest x-ray showed bilateral pneumothoraces that were subsequently managed with bilateral chest drains and he was intubated and transported to our facility. He arrived stable on 60% oxygen and was easily extubed later that day. A repeat chest x-ray demonstrated bilateral upper lobe atelectasis. Mediastinal structures were positioned in the midline. An echocardiogram showed a 3 x 3 x 4 cm solitary cystic mass in the anterior-superior mediastinum. A thoracic computed tomography (CT) scan confirmed these findings and also demonstrated posteriorlateral displacement of the superior vena cava. No structural abnormality was identified at bronchoscopy and esophagoscopy. Despite being hemodynamically stable, tachypnea remained a constant feature. At 3 weeks of age, sternotomy and resection of the lesion was performed. The mass was clearly intrapericardial and anterior to the right atrium and great vessels. No pericardial defect was present. Twenty milliliters of clear yellow pericardial fluid was suctioned. The mass was attached along the superior pericardium to the distal trachea by a solid fibrocartilagenous stalk and fed by several systemic tributaries posterior-laterally. There was no connection with the heart or great vessels. The mass was dark red, pyramidal in shape, with a smooth glistening surface and had the consistency of liver. A large 3.5-cm diameter solitary mucus-filled cyst was eccentrically located along the superior JournalofPediafric Surgery, Vol27, No 10 (October), 1992: pp 1361-1363
aspect of this mass. The baby’s postoperative recovery was uneventful.
Pathologic Examination Gross examination showed a purple, pyramid-shaped specimen invested in pleura weighing 30 g and measuring 5.0 x 3.5 x 3.0 cm. Cut surfaces showed a stalk of cartilaginous tissue present at the apex followed by a 3.5-cm diameter cyst with a thin trabeculated wall containing opaque white mucoid material. Lung parenchyma was located toward the base of the lesion (Fig 1). Microscopic examination showed the cyst to be lined by pseudostratified respiratory epithelium (Fig 2). Large plates of cartilage and mucous glands were identified toward the stalk suggestive of a bronchus. Progressive loss of cartilage was identified toward the body of the cyst. The sequestrated component showed intrapulmonary bronchi, a mild proliferation of bronchioles, and slight dilatation of alveoli (Fig 3). There was no evidence of gastrointestinal tissue nor were there ectodermal elements to suggest a teratoma. DISCUSSION
Intrapericardial masses are uncommon congenital anomalies; intrapericardial sequestrations are particularly rare. Teratomas are the most common tumor in this location in the pediatric age group.’ Deenadayalu et al reviewed 31 intrapericardial teratomas and 21 intrapericardial bronchogenic cystsS2 They determined that some previous cases of bronchogenic cysts were misinterpreted and reported as being teratomas. Only two reports of intrapericardial pulmonary sequestrations have been reported.3,4 This number may actually be greater since some intrapericardial sequestrations may have also been misclassified as teratoma or “teratoid” tumors.3 To our knowledge, our case represents the first intrapericardial pulmonary sequestration associated with a bronchogenic cyst. Pulmonary sequestration and bronchogenic cysts constitute part of a spectrum of congenital bronchopulmonary malformations. As illustrated in this case, and as reported by others, bronchogenic cysts may coexist with sequestrations.5-s Many theories have been proposed to explain the etiology of such anoma-
From the Departments of Surgery, Pathology and Neonatology, Royal Alexandra Hospital, Edmonton, Alberta. Presented at the 23rd Annual Meeting of the Canadian Association of Paediatric Surgeons, Quebec City, Quebec, September 19-22. 1991. Address reprint requests to A.H. Hayashi, MD, Allin Clinic, Department of Surgery, 10155-120 St, Edmonton, Alberta T5K U2, Canada. Copyright o 1992 by WB. Saunders Company 0022-346819212710-0030$03.0010 1361
1362
HAYASHI ET AL
i
Fig 2. The proximal portion of the cyst shows large plates of cartilage with mucous glands. The mucosa (upper left) consists of ciliated pseudostratified respiratory epithelium.
lies. Most support a unified concept where bronchopulmonary malformations arise from abnormal lung bud development.6%9-i1 The embryogenesis of intrapericardial bronchopulmonary malformations can be explained as follows. The lung bud develops at the caudal end of the laryngotracheal tube and grows into the pericardioperitoneal canals (primitive pleural cavities) during the 5th week of development.i2 The primitive heart and lungs at this stage, share a common coelomic cavity and are in close proximity.2 The pleuropericardial membranes begin to appear laterally as ridges of mesenchyme at about the same time.12 By the 6th or 7th week, the pleuropericardial membranes fuse in the midline creating separate pleural and pericardial cavities.12 In the present infant, the separation of lung bud tissue and inclusion within the-pericardial sac must have taken place during this time interval. Timing of embryologic alterations to the lung bud
INTRAPERICARDIAL
1363
MASS IN A NEONATE
during this period may determine the type of intrapericardial lesion. Bronchogenic cysts are believed to originate early in lung bud development, before the bronchi are formed.” Extralobar sequestrations are thought to develop later in time,1°J3 perhaps near the time of pericardial closure, from a supernumerary bud arising caudal to the normally located lung bud. This reasoning may explain why the incidence of intrapericardial bronchogenic cysts significantly outnumber sequestrations. Approximately 50% of patients with intrapericardial tumors present during infancy.2 All infants are symptomatic with signs of respiratory distress or cardiac tamponade. 2,4Echocardiogram and CT scans are sufficient to establish the diagnosis. Once the
diagnosis is determined, management is surgical. This is best approached through a midline sternotomy. Tumor adherence around the root of the aorta has been described and should lead one to proceed in this area with caution.? We have presented a unique case in that the mass described was intrapericardial in location, and consisted of a combination of sequestered lung and bronchogenic cyst. The differential diagnosis of these rare intrapericardial masses in the pediatric age group includes teratomas, hemangiomas, fibromas, and pericardial cysts.r4 ACKNOWLEDGMENT Special thanks to Lisa Hassell for preparation of this manuscript.
REFERENCES 1. Dehner LP: Mediastinum, lungs, and cardiovascular system, in Pediatric Surgical Pathology (ed 2). Baltimore, MD, Williams & Wilkins, 1987, pp 229-333 2. Deenadayalu RP, Tuuri D, Dewall RA, et al: Intrapericardial teratoma and bronchogenic cyst. Review of literature and report of successful surgery in infant with intrapericardial teratoma. J Thorac Cardiovasc Surg 67~945952.1974 3. Baar HS, D’Abreu AL: Duplications of the foregut. Br J Surg 37:220-230,1949 4. Levi A, Findler M, Dolfin T, et al: Intrapericardial extralobar pulmonary sequestration in a neonate. Chest 98:1014-1015, 1990 5. Stocker JT, Kagan-Hallet K: Extralobar pulmonary sequestration. Am J Clin Path01 72:917-925, 1979 6. Demos NJ, Teresi A: Congenital lung malformations. A unified concept and a case report. J Thorac Cardiovasc Surg 70:260-264, 1975 7. Ramenofsky ML, Leape LL, McCauley RGK: Bronchogenic cyst. J Pediatr Surg 14:219-224,1979 8. Gerle RD, Jaretzki A, Ashley CA, et al: Congenital broncho-
pulmonary foregut malformation. Pulmonary sequestration communicating with the gastrointestinal tract. N Engl J Med 278:14131419.1968 9. Luck SR, Reynolds M, Raffensperger JG: Congenital bronchopulmonary malformations. Curr Prob Surg 23:246-314, 1986 10. Heithoff KB, Sane SM, Williams HJ, et al: Bronchopulmonary foregut malformations. A unifying etiological concept. AJR Am J Roentgen01 126:46-55, 1976 11. Sieber WK: Lung cysts, sequestration, and bronchopulmonary dysplasia, in Welch KJ, Randolph JG, Ravitch MM, et al (eds): Pediatric Surgery (ed 4). Chicago, IL, Year Book. 1986, pp 645-654 12. Moore KL: The Developing Human (ed 3). Philadelphia, PA, Saunders, 1982 13. Bailey PV. Tracy T, Connors RH, et al: Congenitaly bronchopulmonary malformations. Diagnostic and therapeutic considerations. J Thorac Cardiovasc Surg 99:597-603, 1990 14. McAllister HA: Primary tumors and cysts of the heart and pericardium. Curr Prob Cardiol4:8-27,1979
