Retropharyngeal Masses in Infants and Young Children Thomas A. McCook, MD, Alvin H. Felman, MD
\s=b\ Six patients are described who illustrate different causes of retropharyngeal mass lesions in infants and young children. Differential diagnosis, clinical history, physical examination, and adequate roentgenographic evaluation of the neck
important. (Am J Dis Child 133:41-43, 1979)
are
airway resulting Upper prevertebral urgent life-threatening
obstruction from a mass is an and often con¬ dition. Roentgenographs of this area usually pinpoint the site and extent of involvement, and for some conditions, they are sufficient for establishing the diagnosis. Our purpose is to present the roent¬ genographic and clinical features of six patients with retropharyngeal masses of different etiologies. A review of the literature and an addi¬ tional differential diagnosis are in¬ cluded (Table 1). REPORT OF CASES Case 1.—A 1.5 x 1.5-cm mass was dis¬ covered in the left side of the neck of a 3-week-old girl. This gradually increased in
From the Departments of Radiology and Pediatrics (Dr Felman), University of Florida College of Medicine in the J. Hillis Miller Health Center, Gainesville, Fla. Dr McCook is now with the Department of Radiology, Duke University Medical Center, Durham, NC. Reprint requests to Department of Radiology, Box J-374, J. Hillis Miller Health Center, Gainesville, FL 32610 (Dr Felman).
size and at 3 months of age she was admitted to the hospital in respiratory distress. A large cystic hygroma was resected and the patient was discharged in good condition. Two months later, with no external mass evident, her respiratory distress recurred. She was referred to Shands Teaching Hospital, Gainesville, Fla, where lateral roentgenographs of the neck showed a prevertebral mass from C-l to C-3, displacing the trachea anteriorly
(Fig 1). A recurrent cystic hygroma was surgically removed from the retropharyn¬ geal area and the infant was discharged in good condition. She remains asymptomatic
after two years. Case 2.-A palpable anterior cervical lymph node developed in a 6-month-old boy. It gradually enlarged over the next 12 months, at which time a biopsy specimen showed it to be a lymph node containing metastatic ganglioneuroblastoma. On re¬ ferral to our hospital, roentgenographs of the cervical spine disclosed a retropharyn¬ geal mass containing fine granular calcifi¬ cations extending from C-l to C-4 and displacing the larynx and trachea anterior¬ ly (Fig 2). A 4 x 6-cm ganglioneuroblasto¬ ma of the retropharyngeal space arising from the cervical sympathetic chain was removed along with perijugular lymph nodes up to the base of the skull. The child received radiation therapy and is free of disease after three years. Case 3.-A 6-month-old boy had coryza of two weeks' duration, low-grade fever, and four days of dyspnea, "noisy breathing," and occasional episodes of apnea. Results of physical examination showed he had edema of the pharynx without tonsillitis, and bilateral tender cervical swelling,
Downloaded From: http://archpedi.jamanetwork.com/ by a Monash University Library User on 06/17/2015
greater
on
the left. Hematocrit level
was
36%; the WBC count was 18,300/cu mm (72% lymphocytes, 24% polymorphonuclear leukocytes). Lateral neck roentgenographs disclosed a retropharyngeal mass displac¬ ing the trachea anteriorly (Fig 3). Emer¬
tracheostomy was performed be¬ of increasing dyspnea. The retropha¬ ryngeal mass was incised and proved to be an abscess caused by group A, /3-hemolytic streptococci. The child was discharged in excellent health after surgical drainage and penicillin therapy. Case 4.—A 15-day-old boy was trans¬ ferred to our hospital because of feeding difficulty since birth. He had been vomit¬ ing blood-tinged material for one day but there was no history of pharyngeal-esophageal instrumentation. Results of physical and laboratory examinations were normal.
gency cause
Table 1.—Origin of Retropharyngeal Masses in Infant and Young Child
the
Infection Abscess Inflammation with edema
Neoplasms Cystic hygroma Hemangioma Neuroblastoma Neurofibroma
Retropharyngeal goiter
Metabolic
Hypothyroidism (congenital myxed¬ ema)
Trauma
Foreign body, instrumentation, cer¬ vical spine injury Lymphadenopathy Histiocytosis X, lymphoma, tubercu¬ losis (scrofula)
1. Cystic lymphangioma. Mass is visible anterior to cervical verte¬ brae and bulges into hypopharynx (ar¬
Fig 1.—Case rows).
Fig 2.—Case 2. Neuroblastoma. Hypo¬ pharynx, partially outlined by swal¬ lowed barium, is displaced anteriorly. Fine, speckled, punctate calcific densi¬ ties are visible throughout retropharyn¬ geal mass.
3.—Case 3. Retropharyngeal abscess. Barium-filled hypopharynx is displaced anteri¬ orly by large homogeneous, prevertebral soft tissue mass. Barium is also present in upper
Fig
esophagus.
Fig 4.—Case 4. Left, Retropharyngeal fistula. Preliminary lateral roentgenogram shows air in prevertebral soft tissues. Right, Swallowed barium has entered this fistulous tract (arrows).
Plain roentgenographs and barium swal¬ low disclosed a fistulous tract extending from the hypopharynx to the retropharyn¬ geal soft tissues, with widening of this area (Fig 4). After placement of a feeding gastrostomy, the retropharyngeal fistula healed and the child is well four years later. Case 5.-A 6-week-old boy was referred to the hospital because of respiratory diffi¬ culty and noisy breathing since birth. On admission he showed substantial respirato¬ ry stridor and subcostal retractions. Re¬ sults of physical examination were other¬ wise unremarkable. The stridor was relieved by hyperextension, and it wors¬ ened with flexion of the neck. A retropha¬ ryngeal mass was seen on a lateral cervical roentgenograph (Fig 5). Bronchoscopy and laryngoscopy showed a bilateral, soft, easi¬ ly movable mass in the prevertebral area. Respiratory arrest requiring intubation occurred several hours later. Surgical exploration of the neck was performed and the isthmus of a grossly enlarged thyroid gland was removed. Pathologic examina¬ tion showed inactive follicles consistent with congenital goiter. Postoperative se¬ rum thyroxine iodine level was 7.2 ug/dl (normal, 3.8 to 8.3 ug/dl). The patient was discharged on a regimen of levothyroxine sodium (Synthroid) and is well two years
postoperatively. 5. Retropharyngeal goiter. Barium swallow shows hypopharynx dis¬ placed anteriorly by mass that proved at surgery to be thyroid tissue.
Fig 5.—Case
Fig
6—Case 6.
Hypothyroid. Homogene¬ ous, retropharyngeal soft tissue swelling is present.
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Case 6.—A 3-month-old girl was trans¬ ferred to our hospital in respiratory distress. There was a history of poor feed¬ ing, aphonia, and intermittent apneic
spells, some of which required mouth-tomouth resuscitation. In addition to upper airway stridor, the child showed many of the clinical features of hypothyroidism, including a wrinkled forehead, enlarged and thickened tongue, weakness of the extremities, hypothermia, and a hoarse cry. Results of a physical examination of the neck were normal. Roentgenographic evaluation disclosed widened retropharyn¬ geal soft tissue (Fig 6), absent ossification of the proximal humeral epiphyses, "beaked" appearance of L-2 and L-4 verte¬ bral bodies, and neonatal bone age. Serum thyroxine iodine level was 2.5 fig/dl (normal, 3.8 to 8.3 ug/dl), and the thyroid scan showed no uptake. Treatment was begun with desiccated thyroid, 65 mg/day, and within two days the respiratory distress subsided and the child showed substantial clinical improvement. She moved away and was lost to follow-up.
Roentgenographic
studies are im¬ portant in the evaluation of infants and children with cervical adenopa¬ mass
lesions,
or
respiratory
distress. Frontal and lateral roentgen¬ ograms of the neck and airway are the minimum studies needed and may be diagnostic. To determine if there is a fixed or a transient prevertebral thickening, barium swallow with fluoroscopy, in addition to demonstra¬ tion of a fistulous tract, if present, may be easier and less time-consum¬ ing procedures. Careful attention to positioning and technique is impor¬ tant since the thickness of the prever¬ tebral soft tissues in infants and small children can vary widely depending on the phase of respiration and the posi¬ tion of the neck.' Two criteria for diagnosis of wid¬ ened retropharyngeal spaces have been proposed. Hay3 in 1930, and later, Lusted and Keats,4 stated that in the first year of life, the normal thickness of the prevertebral tissues never exceeds 1.5 times the anteroposterior depth of C-4, and from 1 to 2 years of age, it does not exceed 0.5 times the anteroposterior depth of the body of that vertebra. We prefer the more -
usually present at birth, they are frequently located in the posteri¬ or cervical triangle, and they often fluctuate in size with crying or respi¬ are
most
rations. Extension into the neck or mediastinum is not uncommon. Histo¬
logically benign, they frequently recur and may cause difficulty with respira¬ tions or swallowing." Hemangiomas are
less
same
COMMENT
thy,
suggested by Ardran and Kemp,' whereby, in infants, "the thickness of the tissue between the pharyngeal lumen and the vertebrae should be about three quarters of the anteroposterior diameter of the body of an adjacent vertebra." Cystic hygroma of lymphangioma is the most common tumor of the retro¬ pharyngeal space in childhood.5 These recent criterion
common
but may
occur
in the
area.s
Primary neurogenic neoplasms aris¬ ing in the neck are uncommon but
instrumentation, and cervical spine trauma are all sources of retropharyn¬ geal inflammation. Congenital or acquired thyroid goi¬ ter
may obtain sufficient size
must be considered in the differential diagnosis of masses in this area.7
Congenital neurofibroma and primary
neuroblastoma of the vagus nerve or cervical sympathetic trunk are even " rarer but have been reported.8 Two patients with primary neuroblastoma of the retropharyngeal area seen at our institution in the last three years had calcifications in the tumors, a
finding strongly suggesting a neuro¬ genic origin. In one patient (case 2), surgery and radiation therapy were curative; the other patient died with widespread metastasis. Abscess in the retropharyngeal space is an infrequent but serious
condition that demands prompt recog¬ nition and treatment. Difficulty in swallowing, obstruction of the upper respiratory tract, and fever are the usual symptoms. Rupture into the
esophagus, mediastinum, or larynx, as
well as blood vessel erosion and severe
hemorrhage, are possible conse¬ quences of delayed treatment."' These infections may develop as complica¬ tions of pharyngeal and tonsillar inflammation to the
area.
or
from direct trauma
Foreign body ingestion,
Downloaded From: http://archpedi.jamanetwork.com/ by a Monash University Library User on 06/17/2015
to
displace the trachea anteriorly and cause respiratory distress. The diag¬ nosis may be made from plain roent¬ genograms, but confirmation is needed by radioisotope scanning.511 Swelling of the retropharyngeal soft tissues, with or without respiratory difficulty, should alert the physician to the possibility of infantile hypothy¬ roidism. In one study of 12 infants with confirmed hypothyroidism who had lateral neck roentgenograms tak¬ en because of respiratory difficulty or abnormal appearance of the face or skull, all were found to have thickened retropharyngeal soft tissues.'References 1. Ardran GM, Kemp FH: The mechanism of changes in form of cervical airway in infancy. Med Radiogr Photogr 44:26-38, 1968. 2. Brenner GH: Variations in the depth of the cervical prevertebral tissues in normal infants studied by cinefluorography. Am J Roentgenol
91:573-577, 1964.
3. Hay PD Jr: The neck, in Case JT (ed): Annals of Roentgenology. New York, Paul B Hoeber Inc, 1930, vol 9. 4. Lusted LB, Keats TE: Atlas of Roentgenogaphic Measurement, ed 3. Chicago, Year Book Medical Publisher Inc, 1972, chap 2, p 26. 5. Swischuck LE, Smith PC, Fagan CJ: Abnormalities of the pharynx and larynx in childhood. Semin Roentgenol, vol 9. 4:283-300, 1974. 6. Barnhart RA, Brown AK: Cystic hygroma of the neck. Arch Otolaryngol 86:100-104, 1967. 7. Rosenfield L, Grawes H, Lawrence R: Primary neurogenic tumors of the lateral neck. Ann Surg 167:847-855, 1968. 8. Steichen FM, Emhorn AH, Fellim A, et al: Congenital retropharyngeal neurofibroma causing laryngeal obstruction in a newborn. J Pediatr Surg 6:480-483, 1971. 9. Rosedale RS: Neuroblastoma of nodose ganglion of infant vagus nerve. Arch Otolaryngol 80:454-459, 1964. 10. Capitanio MA, Kirkpatrick JA Jr: Upper respiratory tract obstruction in infants and children. Radiol Clin North Amer 6:265-277, 1968. 11. Dunbar JS: Upper respiratory tract obstruction in infants and children. Am J Roentgenol 109:225-246, 1970. 12. Gr\l=u"\nebaumM, Noslsowity G: The retropharyngeal soft tissues in young infants with hypothyroidism. Am J Roentgenol 108:543-545, 1970.
\s=b\ Six patients are described who illustrate different causes of retropharyngeal mass lesions in infants and young children. Differential diagnosis, clinical history, physical examination, and adequate roentgenographic evaluation of the neck
important. (Am J Dis Child 133:41-43, 1979)
are
airway resulting Upper prevertebral urgent life-threatening
obstruction from a mass is an and often con¬ dition. Roentgenographs of this area usually pinpoint the site and extent of involvement, and for some conditions, they are sufficient for establishing the diagnosis. Our purpose is to present the roent¬ genographic and clinical features of six patients with retropharyngeal masses of different etiologies. A review of the literature and an addi¬ tional differential diagnosis are in¬ cluded (Table 1). REPORT OF CASES Case 1.—A 1.5 x 1.5-cm mass was dis¬ covered in the left side of the neck of a 3-week-old girl. This gradually increased in
From the Departments of Radiology and Pediatrics (Dr Felman), University of Florida College of Medicine in the J. Hillis Miller Health Center, Gainesville, Fla. Dr McCook is now with the Department of Radiology, Duke University Medical Center, Durham, NC. Reprint requests to Department of Radiology, Box J-374, J. Hillis Miller Health Center, Gainesville, FL 32610 (Dr Felman).
size and at 3 months of age she was admitted to the hospital in respiratory distress. A large cystic hygroma was resected and the patient was discharged in good condition. Two months later, with no external mass evident, her respiratory distress recurred. She was referred to Shands Teaching Hospital, Gainesville, Fla, where lateral roentgenographs of the neck showed a prevertebral mass from C-l to C-3, displacing the trachea anteriorly
(Fig 1). A recurrent cystic hygroma was surgically removed from the retropharyn¬ geal area and the infant was discharged in good condition. She remains asymptomatic
after two years. Case 2.-A palpable anterior cervical lymph node developed in a 6-month-old boy. It gradually enlarged over the next 12 months, at which time a biopsy specimen showed it to be a lymph node containing metastatic ganglioneuroblastoma. On re¬ ferral to our hospital, roentgenographs of the cervical spine disclosed a retropharyn¬ geal mass containing fine granular calcifi¬ cations extending from C-l to C-4 and displacing the larynx and trachea anterior¬ ly (Fig 2). A 4 x 6-cm ganglioneuroblasto¬ ma of the retropharyngeal space arising from the cervical sympathetic chain was removed along with perijugular lymph nodes up to the base of the skull. The child received radiation therapy and is free of disease after three years. Case 3.-A 6-month-old boy had coryza of two weeks' duration, low-grade fever, and four days of dyspnea, "noisy breathing," and occasional episodes of apnea. Results of physical examination showed he had edema of the pharynx without tonsillitis, and bilateral tender cervical swelling,
Downloaded From: http://archpedi.jamanetwork.com/ by a Monash University Library User on 06/17/2015
greater
on
the left. Hematocrit level
was
36%; the WBC count was 18,300/cu mm (72% lymphocytes, 24% polymorphonuclear leukocytes). Lateral neck roentgenographs disclosed a retropharyngeal mass displac¬ ing the trachea anteriorly (Fig 3). Emer¬
tracheostomy was performed be¬ of increasing dyspnea. The retropha¬ ryngeal mass was incised and proved to be an abscess caused by group A, /3-hemolytic streptococci. The child was discharged in excellent health after surgical drainage and penicillin therapy. Case 4.—A 15-day-old boy was trans¬ ferred to our hospital because of feeding difficulty since birth. He had been vomit¬ ing blood-tinged material for one day but there was no history of pharyngeal-esophageal instrumentation. Results of physical and laboratory examinations were normal.
gency cause
Table 1.—Origin of Retropharyngeal Masses in Infant and Young Child
the
Infection Abscess Inflammation with edema
Neoplasms Cystic hygroma Hemangioma Neuroblastoma Neurofibroma
Retropharyngeal goiter
Metabolic
Hypothyroidism (congenital myxed¬ ema)
Trauma
Foreign body, instrumentation, cer¬ vical spine injury Lymphadenopathy Histiocytosis X, lymphoma, tubercu¬ losis (scrofula)
1. Cystic lymphangioma. Mass is visible anterior to cervical verte¬ brae and bulges into hypopharynx (ar¬
Fig 1.—Case rows).
Fig 2.—Case 2. Neuroblastoma. Hypo¬ pharynx, partially outlined by swal¬ lowed barium, is displaced anteriorly. Fine, speckled, punctate calcific densi¬ ties are visible throughout retropharyn¬ geal mass.
3.—Case 3. Retropharyngeal abscess. Barium-filled hypopharynx is displaced anteri¬ orly by large homogeneous, prevertebral soft tissue mass. Barium is also present in upper
Fig
esophagus.
Fig 4.—Case 4. Left, Retropharyngeal fistula. Preliminary lateral roentgenogram shows air in prevertebral soft tissues. Right, Swallowed barium has entered this fistulous tract (arrows).
Plain roentgenographs and barium swal¬ low disclosed a fistulous tract extending from the hypopharynx to the retropharyn¬ geal soft tissues, with widening of this area (Fig 4). After placement of a feeding gastrostomy, the retropharyngeal fistula healed and the child is well four years later. Case 5.-A 6-week-old boy was referred to the hospital because of respiratory diffi¬ culty and noisy breathing since birth. On admission he showed substantial respirato¬ ry stridor and subcostal retractions. Re¬ sults of physical examination were other¬ wise unremarkable. The stridor was relieved by hyperextension, and it wors¬ ened with flexion of the neck. A retropha¬ ryngeal mass was seen on a lateral cervical roentgenograph (Fig 5). Bronchoscopy and laryngoscopy showed a bilateral, soft, easi¬ ly movable mass in the prevertebral area. Respiratory arrest requiring intubation occurred several hours later. Surgical exploration of the neck was performed and the isthmus of a grossly enlarged thyroid gland was removed. Pathologic examina¬ tion showed inactive follicles consistent with congenital goiter. Postoperative se¬ rum thyroxine iodine level was 7.2 ug/dl (normal, 3.8 to 8.3 ug/dl). The patient was discharged on a regimen of levothyroxine sodium (Synthroid) and is well two years
postoperatively. 5. Retropharyngeal goiter. Barium swallow shows hypopharynx dis¬ placed anteriorly by mass that proved at surgery to be thyroid tissue.
Fig 5.—Case
Fig
6—Case 6.
Hypothyroid. Homogene¬ ous, retropharyngeal soft tissue swelling is present.
Downloaded From: http://archpedi.jamanetwork.com/ by a Monash University Library User on 06/17/2015
Case 6.—A 3-month-old girl was trans¬ ferred to our hospital in respiratory distress. There was a history of poor feed¬ ing, aphonia, and intermittent apneic
spells, some of which required mouth-tomouth resuscitation. In addition to upper airway stridor, the child showed many of the clinical features of hypothyroidism, including a wrinkled forehead, enlarged and thickened tongue, weakness of the extremities, hypothermia, and a hoarse cry. Results of a physical examination of the neck were normal. Roentgenographic evaluation disclosed widened retropharyn¬ geal soft tissue (Fig 6), absent ossification of the proximal humeral epiphyses, "beaked" appearance of L-2 and L-4 verte¬ bral bodies, and neonatal bone age. Serum thyroxine iodine level was 2.5 fig/dl (normal, 3.8 to 8.3 ug/dl), and the thyroid scan showed no uptake. Treatment was begun with desiccated thyroid, 65 mg/day, and within two days the respiratory distress subsided and the child showed substantial clinical improvement. She moved away and was lost to follow-up.
Roentgenographic
studies are im¬ portant in the evaluation of infants and children with cervical adenopa¬ mass
lesions,
or
respiratory
distress. Frontal and lateral roentgen¬ ograms of the neck and airway are the minimum studies needed and may be diagnostic. To determine if there is a fixed or a transient prevertebral thickening, barium swallow with fluoroscopy, in addition to demonstra¬ tion of a fistulous tract, if present, may be easier and less time-consum¬ ing procedures. Careful attention to positioning and technique is impor¬ tant since the thickness of the prever¬ tebral soft tissues in infants and small children can vary widely depending on the phase of respiration and the posi¬ tion of the neck.' Two criteria for diagnosis of wid¬ ened retropharyngeal spaces have been proposed. Hay3 in 1930, and later, Lusted and Keats,4 stated that in the first year of life, the normal thickness of the prevertebral tissues never exceeds 1.5 times the anteroposterior depth of C-4, and from 1 to 2 years of age, it does not exceed 0.5 times the anteroposterior depth of the body of that vertebra. We prefer the more -
usually present at birth, they are frequently located in the posteri¬ or cervical triangle, and they often fluctuate in size with crying or respi¬ are
most
rations. Extension into the neck or mediastinum is not uncommon. Histo¬
logically benign, they frequently recur and may cause difficulty with respira¬ tions or swallowing." Hemangiomas are
less
same
COMMENT
thy,
suggested by Ardran and Kemp,' whereby, in infants, "the thickness of the tissue between the pharyngeal lumen and the vertebrae should be about three quarters of the anteroposterior diameter of the body of an adjacent vertebra." Cystic hygroma of lymphangioma is the most common tumor of the retro¬ pharyngeal space in childhood.5 These recent criterion
common
but may
occur
in the
area.s
Primary neurogenic neoplasms aris¬ ing in the neck are uncommon but
instrumentation, and cervical spine trauma are all sources of retropharyn¬ geal inflammation. Congenital or acquired thyroid goi¬ ter
may obtain sufficient size
must be considered in the differential diagnosis of masses in this area.7
Congenital neurofibroma and primary
neuroblastoma of the vagus nerve or cervical sympathetic trunk are even " rarer but have been reported.8 Two patients with primary neuroblastoma of the retropharyngeal area seen at our institution in the last three years had calcifications in the tumors, a
finding strongly suggesting a neuro¬ genic origin. In one patient (case 2), surgery and radiation therapy were curative; the other patient died with widespread metastasis. Abscess in the retropharyngeal space is an infrequent but serious
condition that demands prompt recog¬ nition and treatment. Difficulty in swallowing, obstruction of the upper respiratory tract, and fever are the usual symptoms. Rupture into the
esophagus, mediastinum, or larynx, as
well as blood vessel erosion and severe
hemorrhage, are possible conse¬ quences of delayed treatment."' These infections may develop as complica¬ tions of pharyngeal and tonsillar inflammation to the
area.
or
from direct trauma
Foreign body ingestion,
Downloaded From: http://archpedi.jamanetwork.com/ by a Monash University Library User on 06/17/2015
to
displace the trachea anteriorly and cause respiratory distress. The diag¬ nosis may be made from plain roent¬ genograms, but confirmation is needed by radioisotope scanning.511 Swelling of the retropharyngeal soft tissues, with or without respiratory difficulty, should alert the physician to the possibility of infantile hypothy¬ roidism. In one study of 12 infants with confirmed hypothyroidism who had lateral neck roentgenograms tak¬ en because of respiratory difficulty or abnormal appearance of the face or skull, all were found to have thickened retropharyngeal soft tissues.'References 1. Ardran GM, Kemp FH: The mechanism of changes in form of cervical airway in infancy. Med Radiogr Photogr 44:26-38, 1968. 2. Brenner GH: Variations in the depth of the cervical prevertebral tissues in normal infants studied by cinefluorography. Am J Roentgenol
91:573-577, 1964.
3. Hay PD Jr: The neck, in Case JT (ed): Annals of Roentgenology. New York, Paul B Hoeber Inc, 1930, vol 9. 4. Lusted LB, Keats TE: Atlas of Roentgenogaphic Measurement, ed 3. Chicago, Year Book Medical Publisher Inc, 1972, chap 2, p 26. 5. Swischuck LE, Smith PC, Fagan CJ: Abnormalities of the pharynx and larynx in childhood. Semin Roentgenol, vol 9. 4:283-300, 1974. 6. Barnhart RA, Brown AK: Cystic hygroma of the neck. Arch Otolaryngol 86:100-104, 1967. 7. Rosenfield L, Grawes H, Lawrence R: Primary neurogenic tumors of the lateral neck. Ann Surg 167:847-855, 1968. 8. Steichen FM, Emhorn AH, Fellim A, et al: Congenital retropharyngeal neurofibroma causing laryngeal obstruction in a newborn. J Pediatr Surg 6:480-483, 1971. 9. Rosedale RS: Neuroblastoma of nodose ganglion of infant vagus nerve. Arch Otolaryngol 80:454-459, 1964. 10. Capitanio MA, Kirkpatrick JA Jr: Upper respiratory tract obstruction in infants and children. Radiol Clin North Amer 6:265-277, 1968. 11. Dunbar JS: Upper respiratory tract obstruction in infants and children. Am J Roentgenol 109:225-246, 1970. 12. Gr\l=u"\nebaumM, Noslsowity G: The retropharyngeal soft tissues in young infants with hypothyroidism. Am J Roentgenol 108:543-545, 1970.
