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Posterior mediastinal accessory thymus
BRIEF C L I N I C A L A N D LABORATORY OBSERVATIONS
Articles in this section should require less than three JOURNAL pages: text, less than 1,000 words; 1 or 2 illustrations and/or tables; up to 10 references.
Posterior mediastinal accessory thymus Michel Saade, M.D., Dana M. Whitten, M.D.,* Thomas F. Necheles, M.D., Lucian Leape, M.D., and Donald Darling, M . D . , Boston, Mass.
Two
C H I L D R E N , each with p o s t e r i o r m e d i a s t i n a l m a s s ,
u n d e r w e n t a t h o r a c o t o m y for s u s p e c t e d n e o p l a s m . A c c e s sory t h y m i c tissue, s e p a r a t e
from
a normal
bilobed
t h y m u s in the usual position, was f o u n d in e a c h child. Ectopic t h y m i c tissue s h o u l d be i n c l u d e d in t h e d i f f e r e n tial diagnosis o f a p o s t e r i o r m e d i a s t i n a l m a s s in a child. CASE REPORTS
Case 1. Patient C. C., a 9-week-old male infant, was admitted for a posterior mediastinal mass detected on chest roentgenogram during an evaluation because of low-set ears. He was the product of a term, uncomplicated pregnancy. Height, weight and skull circumference were in the ninetieth percentile and examination was otherwise normal. The hemoglobin concentration was 9.4 gm/dl, the hematocrit value, 26.5%, and the white blood count, 8,300, with 86% lymphocytes, 6% polymorphonucleocytes, 5% monocytes, and 3% eosinophils. Serum concentrations of calcium and phosphorus were normal. A urine spot specimen for VMA was 6/~g/mg creatinine (normal less than 30 t~g/mg creatinine). The chest roentgenogram (Fig. 1) showed a right superior mediastinal mass posterior to the thymus at the level of the great vessels. Results of IVP, barium swallow, electrocardiogram, and chromosome analysis were normal. A three-day course of prednisone, 15 mg/day, failed to reduce the size of the mass. At thoracotomy the mass was found to be From the Department o f Pediatrics, Tufts-New England Medical Center, and the Boston Floating Hospital. Supported in part by The American Cancer Society (Dr. Whitten). *Reprint address: Box 209, New England Medical Center Hospitals, 171 Harrison Ave. Boston, Mass. 02111.
Fig. 1. Chest roentgenogram Case 1, showing the right border of the normal thymus (single arrows) and the separate overlapping accessory gland (double arrow). located posterior to the superior vena cava and superior to the azygos vein. Grossly it resembled the normal thymus which was separate and in its normal location. It measured 7 x 6 x 4 cm, was multilobular, and was completely resected following frozen section examination. Normal thymic tissue was found on histologic examination.
Abbreviations used VMA: vanilmandelic acid IVP: intravenous pyelogram
Case 2. Patient W. J., a 9-month-old male, was admitted because of a posterior mediastinal mass found on chest radiography performed because of recurrent cough and wheezing present for seven months. Height, weight, and skull circumference were normal for age. Injected nasal mucosa and bilateral pulmonary rhonchi were found; the examination was otherwise normal. The hemoglobin concentration was 13.2 gm/dl, the white
The Journal o f P E D I A T R l C S
71
72
Brief clinical and laboratory observations
Table I. Entities usually considered in the differential diagnosis of posterior mediastinal mass Neurogenic neoplasm Mesenteric cyst Esophageal cyst Mediastinal abscess Extramedullary hematopoiesis Intrathoracic meningocele Bronchoesophageal cyst Lymphoma Aneurysm of descending aorta Thoracic duct cyst Spinal neoplastic process Mesenchymal tumor
blood count, 13,500, with 65% lymphocytes,20% polymorphonu cleocytes, 2% bands, 2% metamyelocytes,2% monoeytes, and 6% eosinophils. Serum concentrations of calcium and phosphorus were normal. The urine spot examination for VMA was 15/~g/mg creatinine. The chest roentgenogram showed a posterior superior mediasfinal mass separate from a normal thymic shadow. Results of an WP, bone survey, and Gallium scan were normal. At thoracotomy a 3 • 5 • 2 cm mass resembling normal thymic tissue was located posterior to the superior vena cava lying along the right side of the trachea. After a normal thymus gland was identified in its usual location, the mass was removed. Histologic examination revealed thymic tissue in involution. DISCUSSION Ectopic thymic tissue has been identified in the cavum t y m p a n i / a t the angle of the mandible,~in the neck ~-7and
The Journal of Pediatrics January 1976
in the pharynx? A thymoma, arising in the posterior mediastinum, has been reported. 9 Entities usually included in the differential diagnosis of posterior mediastinal mass of childhood are listed in Table I. 1~ Posterior mediastinal ectopic thymic tissue in the presence of thymus in the normal location is not readily explained by the embryologic development of this organ? ~Accessory thymic tissue must be considered when evaluating a mass in the posterior mediastinum.
REFERENCES 1. HagensEW: Malformation of the auditory apparatus in the newborn, associated with ectopic thymus, Arch Otolarygol 15:671, 1932. 2. Finch DRA and Gough MH: Ectopic thymic tissue presenting as a lateral cervical swelling, Br J Surg 59:885, 1972. 3. Sharp EW: A case of persistent aberrant thymus, Lancet 1:436, 1906. 4. Lewis MR: Persistence of the thymus in the cervical area, PEDIATR61:887, 1962. 5. Casfleman B: Tumors of the thymus gland, Atlas, Armed Forces Institute of Pathology, Sec. 5, Fascicle 19:7, 1955. 6. AnaheimEE, and Gemson BL: Persistent cervical thymus gland, thymecotomy, Surgery 27:603, 1950. 7. Barrick B, and O'Kell RT: Thymic cysts and remnant cervical thymus, J Pediatr Surg 4:355, 1969. 8. Epstein HC, and Loeb WJ: Thymic tumor of the pharynx, PEDIATR47:105, 1955. 9. Cooper GN Jr, and Narodick BG: Posterior mediastinal thymoma. J Thorac Cardiovasc Surg 63:561, 1972. 10. Felson B: The mediastinum, in Chest roentgenology, Philadelphia, 1973, W. B. Saunders Company. 11. Patten BN: Human embryology,New York, 1946, Blakiston Company, pp 536-537.
Countercurrent immunoe lectrop horesis for the diagnosis of pneumococcal pneumonia in children
THE DIAGNOSIS of pneumoccal pneumonia is often difficult to establish in children, since sputum for culture may not be obtainable and since pneumococci are often found in the nasopharynx of asymptomatic children. The diagnosis is secure if the organism is grown from blood or pleural fluid, but these cultures are often negative. Other invasive techniques, such as lung and transtracheal aspi-
Richard H. Miehaels, M.D.,* and Cindy S.
raUon, may increase diagnostic accuracy, but pediatricians have usually reserved them for situations where there is the greatest need to know the etiology. Furthermore, children with pneumococcal pneumonia may already be receiving antibiotics which interfere with the culture of these very susceptible organisms. The detection of specific bacterial polysaccharide antigens in body fluids by countercurrent immunoelectrophoresis has been found
Poziviak, Pittsburgh, Pa.
From the Department of Pediatrics, University of Pittsburgh School of Medicine, and Children's Hospital of Pittsburgh. *Reprint address: Children's Hospital of Pinsburgh, Pittsburgh, Pa. 15213.
Abbreviation used CIE: countercurrent immunoeleetrophoresis
[
Articles in this section should require less than three JOURNAL pages: text, less than 1,000 words; 1 or 2 illustrations and/or tables; up to 10 references.
Posterior mediastinal accessory thymus Michel Saade, M.D., Dana M. Whitten, M.D.,* Thomas F. Necheles, M.D., Lucian Leape, M.D., and Donald Darling, M . D . , Boston, Mass.
Two
C H I L D R E N , each with p o s t e r i o r m e d i a s t i n a l m a s s ,
u n d e r w e n t a t h o r a c o t o m y for s u s p e c t e d n e o p l a s m . A c c e s sory t h y m i c tissue, s e p a r a t e
from
a normal
bilobed
t h y m u s in the usual position, was f o u n d in e a c h child. Ectopic t h y m i c tissue s h o u l d be i n c l u d e d in t h e d i f f e r e n tial diagnosis o f a p o s t e r i o r m e d i a s t i n a l m a s s in a child. CASE REPORTS
Case 1. Patient C. C., a 9-week-old male infant, was admitted for a posterior mediastinal mass detected on chest roentgenogram during an evaluation because of low-set ears. He was the product of a term, uncomplicated pregnancy. Height, weight and skull circumference were in the ninetieth percentile and examination was otherwise normal. The hemoglobin concentration was 9.4 gm/dl, the hematocrit value, 26.5%, and the white blood count, 8,300, with 86% lymphocytes, 6% polymorphonucleocytes, 5% monocytes, and 3% eosinophils. Serum concentrations of calcium and phosphorus were normal. A urine spot specimen for VMA was 6/~g/mg creatinine (normal less than 30 t~g/mg creatinine). The chest roentgenogram (Fig. 1) showed a right superior mediastinal mass posterior to the thymus at the level of the great vessels. Results of IVP, barium swallow, electrocardiogram, and chromosome analysis were normal. A three-day course of prednisone, 15 mg/day, failed to reduce the size of the mass. At thoracotomy the mass was found to be From the Department o f Pediatrics, Tufts-New England Medical Center, and the Boston Floating Hospital. Supported in part by The American Cancer Society (Dr. Whitten). *Reprint address: Box 209, New England Medical Center Hospitals, 171 Harrison Ave. Boston, Mass. 02111.
Fig. 1. Chest roentgenogram Case 1, showing the right border of the normal thymus (single arrows) and the separate overlapping accessory gland (double arrow). located posterior to the superior vena cava and superior to the azygos vein. Grossly it resembled the normal thymus which was separate and in its normal location. It measured 7 x 6 x 4 cm, was multilobular, and was completely resected following frozen section examination. Normal thymic tissue was found on histologic examination.
Abbreviations used VMA: vanilmandelic acid IVP: intravenous pyelogram
Case 2. Patient W. J., a 9-month-old male, was admitted because of a posterior mediastinal mass found on chest radiography performed because of recurrent cough and wheezing present for seven months. Height, weight, and skull circumference were normal for age. Injected nasal mucosa and bilateral pulmonary rhonchi were found; the examination was otherwise normal. The hemoglobin concentration was 13.2 gm/dl, the white
The Journal o f P E D I A T R l C S
71
72
Brief clinical and laboratory observations
Table I. Entities usually considered in the differential diagnosis of posterior mediastinal mass Neurogenic neoplasm Mesenteric cyst Esophageal cyst Mediastinal abscess Extramedullary hematopoiesis Intrathoracic meningocele Bronchoesophageal cyst Lymphoma Aneurysm of descending aorta Thoracic duct cyst Spinal neoplastic process Mesenchymal tumor
blood count, 13,500, with 65% lymphocytes,20% polymorphonu cleocytes, 2% bands, 2% metamyelocytes,2% monoeytes, and 6% eosinophils. Serum concentrations of calcium and phosphorus were normal. The urine spot examination for VMA was 15/~g/mg creatinine. The chest roentgenogram showed a posterior superior mediasfinal mass separate from a normal thymic shadow. Results of an WP, bone survey, and Gallium scan were normal. At thoracotomy a 3 • 5 • 2 cm mass resembling normal thymic tissue was located posterior to the superior vena cava lying along the right side of the trachea. After a normal thymus gland was identified in its usual location, the mass was removed. Histologic examination revealed thymic tissue in involution. DISCUSSION Ectopic thymic tissue has been identified in the cavum t y m p a n i / a t the angle of the mandible,~in the neck ~-7and
The Journal of Pediatrics January 1976
in the pharynx? A thymoma, arising in the posterior mediastinum, has been reported. 9 Entities usually included in the differential diagnosis of posterior mediastinal mass of childhood are listed in Table I. 1~ Posterior mediastinal ectopic thymic tissue in the presence of thymus in the normal location is not readily explained by the embryologic development of this organ? ~Accessory thymic tissue must be considered when evaluating a mass in the posterior mediastinum.
REFERENCES 1. HagensEW: Malformation of the auditory apparatus in the newborn, associated with ectopic thymus, Arch Otolarygol 15:671, 1932. 2. Finch DRA and Gough MH: Ectopic thymic tissue presenting as a lateral cervical swelling, Br J Surg 59:885, 1972. 3. Sharp EW: A case of persistent aberrant thymus, Lancet 1:436, 1906. 4. Lewis MR: Persistence of the thymus in the cervical area, PEDIATR61:887, 1962. 5. Casfleman B: Tumors of the thymus gland, Atlas, Armed Forces Institute of Pathology, Sec. 5, Fascicle 19:7, 1955. 6. AnaheimEE, and Gemson BL: Persistent cervical thymus gland, thymecotomy, Surgery 27:603, 1950. 7. Barrick B, and O'Kell RT: Thymic cysts and remnant cervical thymus, J Pediatr Surg 4:355, 1969. 8. Epstein HC, and Loeb WJ: Thymic tumor of the pharynx, PEDIATR47:105, 1955. 9. Cooper GN Jr, and Narodick BG: Posterior mediastinal thymoma. J Thorac Cardiovasc Surg 63:561, 1972. 10. Felson B: The mediastinum, in Chest roentgenology, Philadelphia, 1973, W. B. Saunders Company. 11. Patten BN: Human embryology,New York, 1946, Blakiston Company, pp 536-537.
Countercurrent immunoe lectrop horesis for the diagnosis of pneumococcal pneumonia in children
THE DIAGNOSIS of pneumoccal pneumonia is often difficult to establish in children, since sputum for culture may not be obtainable and since pneumococci are often found in the nasopharynx of asymptomatic children. The diagnosis is secure if the organism is grown from blood or pleural fluid, but these cultures are often negative. Other invasive techniques, such as lung and transtracheal aspi-
Richard H. Miehaels, M.D.,* and Cindy S.
raUon, may increase diagnostic accuracy, but pediatricians have usually reserved them for situations where there is the greatest need to know the etiology. Furthermore, children with pneumococcal pneumonia may already be receiving antibiotics which interfere with the culture of these very susceptible organisms. The detection of specific bacterial polysaccharide antigens in body fluids by countercurrent immunoelectrophoresis has been found
Poziviak, Pittsburgh, Pa.
From the Department of Pediatrics, University of Pittsburgh School of Medicine, and Children's Hospital of Pittsburgh. *Reprint address: Children's Hospital of Pinsburgh, Pittsburgh, Pa. 15213.
Abbreviation used CIE: countercurrent immunoeleetrophoresis
[