Retroperitoneal Pulmonary Choristoma in a Newborn Calf

Journal of Veterinary Diagnostic Investigation http://vdi.sagepub.com/ Retroperitoneal Pulmonary Choristoma in a Newborn Calf Patrizia Bassi, Arcangelo Gentile and Gianfranco Militerno J VET Diagn Invest 2010 22: 1008 DOI: 10.1177/104063871002200631 The online version of this article can be found at: http://vdi.sagepub.com/content/22/6/1008 Published by: http://www.sagepublications.com On behalf of: Official Publication of the American Association of Veterinary Laboratory Diagnosticians, Inc. Additional services and information for Journal of Veterinary Diagnostic Investigation can be found at: Email Alerts: http://vdi.sagepub.com/cgi/alerts Subscriptions: http://vdi.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav >> Version of Record - Nov 1, 2010 What is This? Downloaded from vdi.sagepub.com by guest on October 11, 2013 1008 Case Reports J Vet Diagn Invest 22:1008–1010 (2010) Retroperitoneal pulmonary choristoma in a newborn calf Patrizia Bassi,1 Arcangelo Gentile, Gianfranco Militerno Abstract. A newborn male Romagnola calf, who had died a few hours after birth, was submitted for postmortem examination. Necropsy revealed a 23 cm 3 22 cm 3 5 cm, pale pink, lobulated, elastic, partially fluctuant mass that protruded from the dorsal retroperitoneal space into the abdominal cavity, extending from the diaphragm to the left kidney. The mass consisted of mature pulmonary tissue and was consistent with a pulmonary choristoma. The gross and microscopic appearance of this rare tumor-like congenital lesion and the possible pathogenesis are discussed. Key words: Calf; cattle; pulmonary choristoma; tumor-like lesion. <!?show "fnote_aff1"$^!"content-markup(./author-grp[1]/aff|./author-grp[1]/dept-list)> A newborn male Romagnola calf, who had died a few hours after birth, underwent necropsy as part of the surveillance program for the so-called ‘‘congenital paunch calf syndrome.’’15 However, the lack of skeletal malformations, ascites, and liver lesions excluded this diagnosis at the initial postmortem examination. Necropsy showed a 23 cm 3 22 cm 3 5 cm, pale pink, lobulated, elastic, partially fluctuant mass that protruded from the dorsal retroperitoneal space into the abdominal cavity, extending from the diaphragm to the left kidney (Fig. 1). The mass was surrounded by a thick, white fibrous wall. It was adjacent to the renal fascia caudally and to the splenic capsule cranioventrally, slightly to the left. There were no adhesions, and the mass was not contiguous with any other abdominal organs or structures. Incision of the wall revealed that the mass did not have any parenchymal continuity with the kidney or the adrenal gland. On cut section, the parenchyma had a soft, elastic consistency. The cut surface was lobulated and pale pink. A cystic cavity 5 cm in diameter, containing a red–brown fluid, was present in the mass (Fig. 2). The total weight of the mass was 1.8 kg. On the basis of the above-mentioned findings, the mass was thought to be an embryonal neoplasm (i.e., nephroblastoma) with the gross appearance of pulmonary tissue but without any apparent communication with the lungs. Representative samples from the mass were collected, fixed in 10% buffered formalin, embedded in paraffin, and routinely processed for histologic examination. Fivemicron sections stained with hematoxylin and eosin revealed normal pulmonary architecture and structures (Fig. 3). Alveoli were dilated, but there was no evidence of protein-rich liquid within. Bronchioles were lined with a single layer of cuboidal and ciliated respiratory epithelium From the Departments of Veterinary Public Health and Animal Pathology (Bassi, Militerno) and Clinical Veterinary (Gentile), Faculty of Veterinary Medicine, Alma Mater Studiorum, University of Bologna, Ozzano Emilia, Bologna, Italy. 1 Corresponding Author: Patrizia Bassi, Department of Veterinary Public Health and Animal Pathology, Faculty of Veterinary Medicine, Alma Mater Studiorum–University of Bologna, via Tolara di Sopra 50, Ozzano Emilia (Bologna) 40064, Italy. [email protected] and were surrounded by smooth muscle fibers. There was no evidence of bronchi or cartilaginous rings. The interstitium consisted of connective tissue septa and blood vessels. On the basis of its microscopic appearance, the abdominal mass was diagnosed as a pulmonary choristoma. A choristoma is a rare congenital tumor-like lesion reported in human beings and other animal species consisting of histologically normal mature tissue located in an anatomic position different from its proper site.9 A pulmonary choristoma is a solitary nonfunctioning mass of pulmonary tissue7,9,10,14 that is composed of normal lung parenchyma but lacks communication with the tracheobronchial tree. It receives its arterial supply from the systemic circulation.5,7,13 In the literature, it is also reported as an ectopic or accessory lung,2,5,7,11–13 bronchopulmonary foregut malformation,7 and extralobar pulmonary sequestration.1,5,7,10,14 In contrast, the term intralobar pulmonary sequestration is used to indicate a nonfunctioning mass of lung tissue located within a normal lobe and lacking its own visceral pleura.5,10,14 Bronchogenic cysts represent supernumerary Figure 1. Abdominal cavity of the calf. Note the pulmonary choristoma (arrows) extending from the retroperitoneal region. The arrowhead indicates the kidney after incision of the choristoma wall. Case Reports 1009 Figure 3. Pulmonary choristoma. Note the alveoli and a central bronchiole lined with ciliated respiratory epithelium. Hematoxylin and eosin. Bar 5 100 mm. Figure 2. Pulmonary choristoma. Note the lobulated cut surface with a central cystic cavity. lung buds from the primitive foregut, but in contrast to sequestrations, the cysts only rarely contain distal lung parenchyma.6 Choristomas can be located in the thoracic cavity (in which case it is separate from the adjacent normal tissue of the lung), the diaphragm, the retroperitoneal and adrenal gland regions, or the subcutaneous tissue. In all these cases, the mass is covered by a distinct pleura. Choristomas occasionally communicate with the digestive tract, usually the esophagus.7,10 The content of the dilated alveoli is presumed to be entrapped fetal lung fluid. Physiologically, the fetal lung fluid produced by the lung epithelium moves from the potential air spaces to the upper airways, where it is either swallowed or released into the amniotic fluid.4 The lack of communication with the tracheobronchial structures would have prevented the removal of this liquid. As reported in the literature, the composition of normal fetal lung fluid, high in chloride and almost protein free,17 could explain its lack of affinity for hematoxylin and eosin stain. In the authors’ opinion, the fluid in the cystic cavity likely has the same origin as that in the alveoli. To the authors’ knowledge, pulmonary choristomas have been reported in cattle in the subcutaneous tissue at the level of the frontal region of the skull,11,13 the zone extending from the occipital bone to the first cervical vertebra,3 the midline of the lower cervical area,2 the neck,12 the shoulders,16 and the right side of the chest.1 The abdominal cavity is another location that has been reported.1,16 A choristoma is believed to be a malformation of the embryonal foregut. The most accepted theory states that an accessory lung bud develops from the caudal aspect of the primitive foregut and migrates caudally along the growing esophagus.2,6–8,11,12 If this accessory lung bud arises early in embryonic life, before the development of the pleura, it is enclosed within an adjacent lung and becomes an intralobar sequestration; if instead this accessory lung bud develops later, when the pleura has already formed, it grows separately from the adjacent lung, is covered with its own pleura, and forms an extralobar sequestration.7 Therefore, the type of bronchopulmonary foregut malformation depends on the stage of embryologic development at which the accessory tissue arises and the direction in which the aberrant pulmonary tissue grows.6 Other authors hypothesize that a choristoma originates from ectopic pluripotential cells that develop in the direction of the respiratory tissue.3,15,18 Another hypothesis suggests that a supernumerary tracheobronchial tube is formed directly from the primitive foregut of the embryo, cranially or caudally to the origin of the normal tracheobronchial tube.16 Prognosis depends on the location of the choristoma; it is favorable in the case of a subcutaneous location because it can easily be removed surgically.2,3,13 Theoretically, the diagnosis of a choristoma might be reached antemortem using ultrasonographic techniques, computed tomography, or magnetic resonance imaging, but to the authors’ knowledge, there have been no such reports in bovine medicine. The in vivo imaging diagnostics in the bovine cases reported until now are limited to radiologic examinations.2,3,11,13 However, a final diagnosis can be confirmed only by histopathologic examination. The present case of a pulmonary choristoma located in the retroperitoneal region is thought to add useful knowledge to the existing information available regarding bovine species. References 1. Brown PJ, Cooke PM, Lucke VN, et al.: 1988, Congenital bronchopulmonary foregut malformations in two young Friesian cattle. Vet Rec 122:208–209. 2. Canpolat I, Eröksüz Y: 2007, Pulmonary sequestration and bronchogenic cyst in a calf. Firat Üniversitesi Saglik Bilimleri Dergisi 21:281–284. 1010 Case Reports 3. Chauvet AE, Lipsitz D, Burek K, Bailey CS: 1994, Pulmonary choristoma in a calf. Can Vet J 35:441–442. 4. Clifton-Koeppel L: 2006, Respiratory review. Newborn Infant Nurs Rev 6:52–56. 5. Damani MN, Ganem JP, Freeman JA: 1999, Intra-abdominal pulmonary sequestration: a benign suprarenal mass. Urology 53:1228. 6. Eom DW, Kang GH, Kim JW, Ryu DS: 2007, Unusual bronchopulmonary foregut malformation associated with pericardial defect: bronchogenic cyst communicating with tubular esophageal duplication. J Korean Med Sci 22:564–567. 7. Heithoff KB, Sane SM, Williams HJ, et al.: 1976, Bronchopulmonary foregut malformations. A unifying etiological concept. AJR Am J Roentgenol 126:46–55. 8. Itoh H, Shitamura T, Kataoka H, et al.: 2002, Retroperitoneal bronchogenic cyst: report of a case and literature review. Pathol Int 49:152–155. 9. Kusewitt DF, Rush LJ: 2007, Neoplasia and tumor biology. In: Pathologic basis of veterinary disease, ed. McGavin MB, Zachary JF, 4th ed., pp. 253–298. Mosby, St. Louis, MO. 10. Langston C: 2003, New concepts in the pathology of congenital lung malformations. Semin Pediatr Surg 12:17–37. View publication stats 11. Lucas MJ, Johnson LW, Haley PJ: 1984, Ectopic lung tissue arising from the head of a neonatal calf. Agri Pract 5:45–48. 12. Maenhout D, Ducatelle R, Hoorens J: 1983, Een geval van ectopische long in de halsstreek van een kalf [A case of an ectopic lung in the neck region of a calf]. Vlaam Dierg 52:21–30, In Dutch. Abstract in English. 13. Medeiros de Oliveira D, Araújo Medeiros JM, de Araújo AL, et al.: 2009, Pulmonary choristoma associated with calf meningocele. Cienc Rural 39:2652–2654. 14. Reiss I, van de Ven CP, Tibboel D: 2008, Congenital lung malformations: diagnostic and therapeutic approaches. Intensivmedizin und Notfallmedizin 45:12–18. 15. Testoni S, Militerno G, Rossi M, Gentile A: 2009, Congenital facial deformities, ascites and hepatic fibrosis in Romagnola calves. Vet Rec 164:693–694. 16. Thomson RG: 1966, Congenital bronchial hypoplasia in calves. Pathol Vet 3:89–109. 17. Wilson SM, Olver RE, Walters DV: 2007, Developmental regulation of luminal lung fluid and electrolyte transport. Respir Physiol Neurobiol 159:247–255. 18. Young TL, Büchi ER, Kaufman LM, et al.: 1990, Respiratory epithelium in a cystic choristoma of the limbus. AMA Arch Opthalmol 108:1736–1739.