Ann Otol Rhinol LaryngollOl:1992
SPONTANEOUS REGRESSION OF JUVENILE NASOPHARYNGEAL ANGIOFIBROMA JOSEPH E. DoHAR, MD
ARNDT J. DUVALL Ill, MD MINNEAPoLIS, MINNEsOTA
There is debate concerning the natural history of juvenile nasopharyngeal angiofibromas, especially whether or not they can spontaneously regress. Often claimed, spontaneous regression has not been well documented. To our knowledge, this is the first report in which a biopsy-proven juvenile nasopharyngeal angiofibroma spontaneously resolved. A second, less well-documented case is discussed. KEY WORDS - nasopharyngeal neoplasms, sclerosing angioma.
Juvenile nasopharyngeal angiofibroma (JNA) is a benign tumor typically affecting adolescent boys. Generally, JNAs are believed to behave in a locally invasive manner and to locally recur in up to 25% of cases.l-? The characteristic geographic pattern of growth has been well outlined by Neel et al. 3 Despite these descriptions of this tumor's usual pattern of behavior, there is nonetheless debate concerning the natural history of this tumor in terms of its ability to malignantly degenerate,2,4-12 present with distant metastasis, 13,14 and, as discussed here, spontaneously resolve. We present a patient with a biopsy-proven recurrent JNA who demonstrates no evidence of tumor on clinical examination or computed tomography (CT) scan 15 years later.
involved the left side of the nasopharynx with extension to the posterior inferior turbinate and the posterior nasal septum, through the pterygomaxillary fissure into the pharyngomaxillary space, and through the anterior wall of the sphenoid sinus. Pathologic analysis of the tissue demonstrated recurrent JNA. Postoperatively, the patient did well until May 1975, when he experienced progressively worsening left nasal obstruction. Physical examination revealed a mass broadly attached to the left superior and lateral nasopharyngeal walls. Biopsy of this mass revealed recurrent JNA. The patient was not significantly bothered by his unilateral nasal obstruction and was therefore managed expectantly. In May 1979, he continued to complain ofleft-sided nasal obstruction, and physical examination revealed a significant septal deviation obstructing the left side of the nose along with persistence of the nasopharyngeal mass, unchanged in appearance since 1975. He underwent septoplasty and a repeat biopsy that again revealed recurrent JNA. He was subsequently lost to followup but returned to the clinic in November 1990 for an unrelated otolaryngologic problem. Examination of his nasopharynx ,atthat time revealed no evidence of tumor and he denied any complaints of nasal obstruction or epistaxis. Nasopharyngeal imaging via highresolution CT scanning with contrast in April 1991 provided radiographic confirmation oftumor resolution (see Figure).
CASE REPORT
A 13-year-old boy presented in September 1969 with a several-year history of severe bilateral nasal obstruction and recurrent epistaxis. He underwent surgical resection of his JNA via a transpalatal approach. He presented again in May 1971with epistaxis and on physical examination was noted to have a recurrence in the nasopharynx. This was initially treated with chemical cautery, but because ofpersisting epistaxis as well as a persisting nasopharyngeal mass, surgical resection was again performed, this time via a transnasal approach. He presented again in December 1972 with recurrence of epistaxis and a left-sided nasopharyngeal mass. He was placed on a regimen of2.5 mg ofPremarin per day, which seemed to reduce the frequency of his nosebleeds. The nasopharyngeal mass, however, continued to grow. At this point, the patient was referred to the University of Minnesota Hospital and Clinic. In April 1973 the patient underwent a third resection of the tumor via an intraoral tripartite approach's accompanied by ligation of the left external carotid artery. The tumor
DISCUSSION
The natural history of JNA is not completely understood. Although this tumor has been said to regress and spontaneously involute at or about the age of puberty, there is little authenticated documentation that untreated lesions do so. Ringertzl'' in 1938 stated that spontaneous regression of these tumors usually occurs when the patient reaches the age of 20
From the Department of Otolaryngology, University of Minnesota Hospital and Clinic, Minneapolis, Minnesota.
469
Downloaded from aor.sagepub.com at CARLETON UNIV on June 20, 2015
470
Dohar & Duvall, Juvenile Nasopharyngeal Angiofibroma
Enhanced computed tomogram from 1991 demonstrating no tumor in nasopharynx at level of 1975 recurrence. Diverticulum on left lateral nasopharyngeal wall and absence of left pterygoid plates are result of 1973 resection.
to 25 by both resorption and disintegration with breaking off of the peripheral processes of the tumor, although he offered no support for his contention. In 1948, Martin et al!? stated that it is probable that some cases of nasopharyngeal fibroma of moderate size occur and regress spontaneously. They supported their statement with the case of a I5-year-old boy who was completely asymptomatic and on physical examination was incidentally noted to have a nasopharyngeal mass. Over 2 1/2 years the tumor was not noted to regress, and there was never tissue confirmation of the diagnosis. Dane'" in 1954 reported a JNA in the process of regression. The spontaneous regression in this case, however, was assumed, with the only documentation of the regression being the patient's history. Witt et alII described a case that they termed a spontaneous regression over 16 months, but
the patient had been treated with two surgical procedures and two courses of radiotherapy. It has been well documented that radiotherapy can continue to affect JNAs for up to several years.'? Stansbie and Phelps-? reported in 1986 the involution of residual JNA documented by means of serial CT scans over a 3-year period. There was no tissue confirmation of the suspected recurrence. It has been our experience that occasional recurrent JNAs are often difficult to distinguish from fibrosis on CT scan. Further, Bremer et al 21reported two instances in which they reexplored patients on the basis of a tumor blush noted on angiography and in both cases found no gross tumor at the time ofexploration. These experiences call into question the reliability of radiographic imaging in diagnosing recurrent JNA. Finally, Jacobsson et al 22 described the regression of a JNA that recurred following surgical resection. The recurrent tumor was treated with embolization of all branches of the external carotid artery, and over 6 years it was followed up with serial CT scans and noted to regress. Because of the questionable documentation in the literature for spontaneous regression of JNAs, some authors have denied that it can occur at alL2,23 We believe that the case described in this paper provides evidence that JNAs can spontaneously regress. Further, we have a second case ofa 13-year-old boy who, after a surgical resection of his initial tumor, developed a recurrence that was followed clinically and noted to progressively decrease in size. Correspondence with his mother in 1973 and with the patient in 1990 revealed that he was having no clinical difficulty and was seeking no further medical treatment for this problem. We present this case as an aside because of lack of objective documentation of spontaneous resolution. These cases lead us to conclude that JNAs, in at least a minority of instances, can spontaneously resolve. To our knowledge, ours represents the only documented biopsy-proven case of JNA with spontaneous resolution.
REFERENCES 1. Goepfert H, Cangir A, Lee Y-Y. Chemotherapy for aggressivejuvenile nasopharyngeal angiofibroma. Arch Otolaryn-
6. Donald Pl. Sarcomatous degeneration in a nasopharyngeal angiofibroma. Otolaryngol Head Neck Surg 1979;87:42-6.
goI1985;111:285-9. 2. Gisselsson L, Lindgren M, Stenram U. Sarcomatous transformation of a juvenile nasopharyngeal angiofibroma. Acta Pathol 1958;42: 305-12.
7. Figi FA, Davis RE. The management of nasopharyngeal fibromas. Laryngoscope 1950;60:794-814.
3. Neel HB,WhickerJH, Devine KD. Juvenile angiofibroma - review of 120 cases. Am J Surg 1973;126:547-60. 4. Batsakis JG, KJoop CT, Newman W. Fibrosarcoma arising in a juvenile nasopharyngeal angiofibroma following extensive radiation therapy. Am Surg 1956;21:786-93. 5. Chen KT, Bauer FW. Sarcomatous transformation of nasopharyngeal angiofibroma. Cancer 1982;49:369-71.
8. Makek MS, Andrews JC, Fisch U. Malignant transformation of a nasopharyngeal angiofibroma. Laryngoscope 1989;99: 1088-92. 9. Massoud GE, Awwad HK. Nasopharyngeal fibroma: its malignant potentials and radiation therapy. Clin Radiol 1960;11: 156-61. 10. Handousa A, Farid H, Elwi AM. Nasopharyngeal fibroma: a clinico-pathological study of 70 cases. J Laryngol Oto1 1954;68:647-66.
Downloaded from aor.sagepub.com at CARLETON UNIV on June 20, 2015
Dohar & Duvall, Juvenile Nasopharyngeal Angiofibroma 11. Witt TR, Shah 1P, Sternberg S. Juvenile nasopharyngeal angiofibroma: a 30-yearclinical review. AmJ Surg 1983; 146:521-
471
angiofibroma. Ann Surg 1948;127:513-36.
5.
18. Dane WHoJuvenile nasopharyngeal angiofibroma in stale of regression. Ann Otol Rhinol LaryngoI1954;63:997-1014.
12. Spagnolo DV, Papadimitriou JM, Archer M. Postirradiation malignant fibrous histiocytoma arising in juvenile nasopharyngeal angiofibroma and producing alpha-I-antitrypsin. Histopathology 1984;8:339-52.
19. McGahan RA, Durrance FY, Parke RB Jr, Easley JO, Chou U. The treatment of advanced juvenile nasopharyngeal angiofibroma. Int J Radiat Oncol BioI Phys 1989;17:1067-72.
13. Perko M, Uehlinger E, Hgorting-Hansen E. Nasopharyngeal angiofibroma of the maxilla. J Oral Surg 1969;27:645-9. 14. Hormia M, Koskinen O. Metastasizing nasopharyngeal angiofibroma. A case report. Arch OtolaryngoI1969;89:523-6. 15. Duvall AJ III, Moreano AB. Juvenile nasopharyngeal angiofibroma: diagosis and treatment. Otolaryngol Head Neck Surg 1987;97:534-40. 16. Ringertz N. Pathology of malignant tumors arising in the nasal and paranasal cavities and maxilla. Acta Otolaryngol [Suppl] (Stockh) 1938(suppl 27): 158-61. 17. Martin H, Ehrlich HE, Abels JC. Juvenile nasopharyngeal
20. Stansbie 1M, Phelps PD. Involution of residual juvenile nasopharyngeal angiofibroma (a case report). 1 Laryngol Otol 1986; 100:599-603. 21. Bremer JW, Neel HB ill, DeSanto LW, Jones GC. Angiofibroma: treatment trends in 150 patients during 40 years. Laryngoscope 1986;96:1321-9. 22. Jacobsson M, Petruson B, Ruth M, Svendsen P. Involution of juvenile nasopharyngeal angiofibroma with intracranial extension. Arch Otolaryngol Head Neck Surg 1989;115:238-9. 23. Chandler JR, Goulding R, Moskowitz L, Quencer RM. Nasopharyngeal angiofibromas: staging and management. Ann Otol Rhinol LaryngoI1984;93:322-9.
ADDENDUM Subsequent to the writing and submission of this article, L. S. Weprin and P. T. Siemers reported a case wherein a JNA spontaneously regressed over a 12-year period without any treatment (Spontaneous Regression of Juvenile Nasopharyngeal Angiofibroma, Arch Otolaryngol Head Neck Surg 1991;117:796-9). The JNA had been diagnosed by biopsy in a child 11 years of age. We believe that this case offers further support that JNA, in a minority of cases, can spontaneously involute.
7m WORLD CONGRESS FOR BRONCHOLOGY & BRONCHOESOPHAGOLOGY The 7th World Congresses for Broncology & Bronchoesophagology will be held Sept 28-0ct 2, 1992, at the Mayo Clinic and Mayo Medical Center in Rochester, Minnesota. For further information, contact Udaya B. S. Prakash, MD, Secretary-General & Director, 7th WeB & WCBE, East-18, Mayo Clinic, Rochester, MN 55905.
THE DEAFNESS RESEARCH FOUNDATION 1993 RESEARCH GRANTS AVAILABLE The Deafness Research Foundation invites applications for 1993 grant support of research projects directed to any aspect of the ear, eg, investigation of function, physiology, biochemistry, genetics, anatomy, or pathology. Grant support is given for one year, in an amount that cannot exceed $15,000, but can competitively be renewed for one or two additional years. Applications are reviewed for the scientific merit of the proposed investigations and for their direct or potential clinical value. The deadlines for applications for 1993 grant support are as follows: first year applications should be postmarked by July 15, 1992, and renewal applications should be postmarked by August 15,1992. For information and applications, contact Wesley H. Bradley, MD, Medical Director, The Deafness Research Foundation, 9 East 38th Street, New York, NY 10016; telephone (212) 684-6556; fax (212) 779-2125.
Downloaded from aor.sagepub.com at CARLETON UNIV on June 20, 2015
SPONTANEOUS REGRESSION OF JUVENILE NASOPHARYNGEAL ANGIOFIBROMA JOSEPH E. DoHAR, MD
ARNDT J. DUVALL Ill, MD MINNEAPoLIS, MINNEsOTA
There is debate concerning the natural history of juvenile nasopharyngeal angiofibromas, especially whether or not they can spontaneously regress. Often claimed, spontaneous regression has not been well documented. To our knowledge, this is the first report in which a biopsy-proven juvenile nasopharyngeal angiofibroma spontaneously resolved. A second, less well-documented case is discussed. KEY WORDS - nasopharyngeal neoplasms, sclerosing angioma.
Juvenile nasopharyngeal angiofibroma (JNA) is a benign tumor typically affecting adolescent boys. Generally, JNAs are believed to behave in a locally invasive manner and to locally recur in up to 25% of cases.l-? The characteristic geographic pattern of growth has been well outlined by Neel et al. 3 Despite these descriptions of this tumor's usual pattern of behavior, there is nonetheless debate concerning the natural history of this tumor in terms of its ability to malignantly degenerate,2,4-12 present with distant metastasis, 13,14 and, as discussed here, spontaneously resolve. We present a patient with a biopsy-proven recurrent JNA who demonstrates no evidence of tumor on clinical examination or computed tomography (CT) scan 15 years later.
involved the left side of the nasopharynx with extension to the posterior inferior turbinate and the posterior nasal septum, through the pterygomaxillary fissure into the pharyngomaxillary space, and through the anterior wall of the sphenoid sinus. Pathologic analysis of the tissue demonstrated recurrent JNA. Postoperatively, the patient did well until May 1975, when he experienced progressively worsening left nasal obstruction. Physical examination revealed a mass broadly attached to the left superior and lateral nasopharyngeal walls. Biopsy of this mass revealed recurrent JNA. The patient was not significantly bothered by his unilateral nasal obstruction and was therefore managed expectantly. In May 1979, he continued to complain ofleft-sided nasal obstruction, and physical examination revealed a significant septal deviation obstructing the left side of the nose along with persistence of the nasopharyngeal mass, unchanged in appearance since 1975. He underwent septoplasty and a repeat biopsy that again revealed recurrent JNA. He was subsequently lost to followup but returned to the clinic in November 1990 for an unrelated otolaryngologic problem. Examination of his nasopharynx ,atthat time revealed no evidence of tumor and he denied any complaints of nasal obstruction or epistaxis. Nasopharyngeal imaging via highresolution CT scanning with contrast in April 1991 provided radiographic confirmation oftumor resolution (see Figure).
CASE REPORT
A 13-year-old boy presented in September 1969 with a several-year history of severe bilateral nasal obstruction and recurrent epistaxis. He underwent surgical resection of his JNA via a transpalatal approach. He presented again in May 1971with epistaxis and on physical examination was noted to have a recurrence in the nasopharynx. This was initially treated with chemical cautery, but because ofpersisting epistaxis as well as a persisting nasopharyngeal mass, surgical resection was again performed, this time via a transnasal approach. He presented again in December 1972 with recurrence of epistaxis and a left-sided nasopharyngeal mass. He was placed on a regimen of2.5 mg ofPremarin per day, which seemed to reduce the frequency of his nosebleeds. The nasopharyngeal mass, however, continued to grow. At this point, the patient was referred to the University of Minnesota Hospital and Clinic. In April 1973 the patient underwent a third resection of the tumor via an intraoral tripartite approach's accompanied by ligation of the left external carotid artery. The tumor
DISCUSSION
The natural history of JNA is not completely understood. Although this tumor has been said to regress and spontaneously involute at or about the age of puberty, there is little authenticated documentation that untreated lesions do so. Ringertzl'' in 1938 stated that spontaneous regression of these tumors usually occurs when the patient reaches the age of 20
From the Department of Otolaryngology, University of Minnesota Hospital and Clinic, Minneapolis, Minnesota.
469
Downloaded from aor.sagepub.com at CARLETON UNIV on June 20, 2015
470
Dohar & Duvall, Juvenile Nasopharyngeal Angiofibroma
Enhanced computed tomogram from 1991 demonstrating no tumor in nasopharynx at level of 1975 recurrence. Diverticulum on left lateral nasopharyngeal wall and absence of left pterygoid plates are result of 1973 resection.
to 25 by both resorption and disintegration with breaking off of the peripheral processes of the tumor, although he offered no support for his contention. In 1948, Martin et al!? stated that it is probable that some cases of nasopharyngeal fibroma of moderate size occur and regress spontaneously. They supported their statement with the case of a I5-year-old boy who was completely asymptomatic and on physical examination was incidentally noted to have a nasopharyngeal mass. Over 2 1/2 years the tumor was not noted to regress, and there was never tissue confirmation of the diagnosis. Dane'" in 1954 reported a JNA in the process of regression. The spontaneous regression in this case, however, was assumed, with the only documentation of the regression being the patient's history. Witt et alII described a case that they termed a spontaneous regression over 16 months, but
the patient had been treated with two surgical procedures and two courses of radiotherapy. It has been well documented that radiotherapy can continue to affect JNAs for up to several years.'? Stansbie and Phelps-? reported in 1986 the involution of residual JNA documented by means of serial CT scans over a 3-year period. There was no tissue confirmation of the suspected recurrence. It has been our experience that occasional recurrent JNAs are often difficult to distinguish from fibrosis on CT scan. Further, Bremer et al 21reported two instances in which they reexplored patients on the basis of a tumor blush noted on angiography and in both cases found no gross tumor at the time ofexploration. These experiences call into question the reliability of radiographic imaging in diagnosing recurrent JNA. Finally, Jacobsson et al 22 described the regression of a JNA that recurred following surgical resection. The recurrent tumor was treated with embolization of all branches of the external carotid artery, and over 6 years it was followed up with serial CT scans and noted to regress. Because of the questionable documentation in the literature for spontaneous regression of JNAs, some authors have denied that it can occur at alL2,23 We believe that the case described in this paper provides evidence that JNAs can spontaneously regress. Further, we have a second case ofa 13-year-old boy who, after a surgical resection of his initial tumor, developed a recurrence that was followed clinically and noted to progressively decrease in size. Correspondence with his mother in 1973 and with the patient in 1990 revealed that he was having no clinical difficulty and was seeking no further medical treatment for this problem. We present this case as an aside because of lack of objective documentation of spontaneous resolution. These cases lead us to conclude that JNAs, in at least a minority of instances, can spontaneously resolve. To our knowledge, ours represents the only documented biopsy-proven case of JNA with spontaneous resolution.
REFERENCES 1. Goepfert H, Cangir A, Lee Y-Y. Chemotherapy for aggressivejuvenile nasopharyngeal angiofibroma. Arch Otolaryn-
6. Donald Pl. Sarcomatous degeneration in a nasopharyngeal angiofibroma. Otolaryngol Head Neck Surg 1979;87:42-6.
goI1985;111:285-9. 2. Gisselsson L, Lindgren M, Stenram U. Sarcomatous transformation of a juvenile nasopharyngeal angiofibroma. Acta Pathol 1958;42: 305-12.
7. Figi FA, Davis RE. The management of nasopharyngeal fibromas. Laryngoscope 1950;60:794-814.
3. Neel HB,WhickerJH, Devine KD. Juvenile angiofibroma - review of 120 cases. Am J Surg 1973;126:547-60. 4. Batsakis JG, KJoop CT, Newman W. Fibrosarcoma arising in a juvenile nasopharyngeal angiofibroma following extensive radiation therapy. Am Surg 1956;21:786-93. 5. Chen KT, Bauer FW. Sarcomatous transformation of nasopharyngeal angiofibroma. Cancer 1982;49:369-71.
8. Makek MS, Andrews JC, Fisch U. Malignant transformation of a nasopharyngeal angiofibroma. Laryngoscope 1989;99: 1088-92. 9. Massoud GE, Awwad HK. Nasopharyngeal fibroma: its malignant potentials and radiation therapy. Clin Radiol 1960;11: 156-61. 10. Handousa A, Farid H, Elwi AM. Nasopharyngeal fibroma: a clinico-pathological study of 70 cases. J Laryngol Oto1 1954;68:647-66.
Downloaded from aor.sagepub.com at CARLETON UNIV on June 20, 2015
Dohar & Duvall, Juvenile Nasopharyngeal Angiofibroma 11. Witt TR, Shah 1P, Sternberg S. Juvenile nasopharyngeal angiofibroma: a 30-yearclinical review. AmJ Surg 1983; 146:521-
471
angiofibroma. Ann Surg 1948;127:513-36.
5.
18. Dane WHoJuvenile nasopharyngeal angiofibroma in stale of regression. Ann Otol Rhinol LaryngoI1954;63:997-1014.
12. Spagnolo DV, Papadimitriou JM, Archer M. Postirradiation malignant fibrous histiocytoma arising in juvenile nasopharyngeal angiofibroma and producing alpha-I-antitrypsin. Histopathology 1984;8:339-52.
19. McGahan RA, Durrance FY, Parke RB Jr, Easley JO, Chou U. The treatment of advanced juvenile nasopharyngeal angiofibroma. Int J Radiat Oncol BioI Phys 1989;17:1067-72.
13. Perko M, Uehlinger E, Hgorting-Hansen E. Nasopharyngeal angiofibroma of the maxilla. J Oral Surg 1969;27:645-9. 14. Hormia M, Koskinen O. Metastasizing nasopharyngeal angiofibroma. A case report. Arch OtolaryngoI1969;89:523-6. 15. Duvall AJ III, Moreano AB. Juvenile nasopharyngeal angiofibroma: diagosis and treatment. Otolaryngol Head Neck Surg 1987;97:534-40. 16. Ringertz N. Pathology of malignant tumors arising in the nasal and paranasal cavities and maxilla. Acta Otolaryngol [Suppl] (Stockh) 1938(suppl 27): 158-61. 17. Martin H, Ehrlich HE, Abels JC. Juvenile nasopharyngeal
20. Stansbie 1M, Phelps PD. Involution of residual juvenile nasopharyngeal angiofibroma (a case report). 1 Laryngol Otol 1986; 100:599-603. 21. Bremer JW, Neel HB ill, DeSanto LW, Jones GC. Angiofibroma: treatment trends in 150 patients during 40 years. Laryngoscope 1986;96:1321-9. 22. Jacobsson M, Petruson B, Ruth M, Svendsen P. Involution of juvenile nasopharyngeal angiofibroma with intracranial extension. Arch Otolaryngol Head Neck Surg 1989;115:238-9. 23. Chandler JR, Goulding R, Moskowitz L, Quencer RM. Nasopharyngeal angiofibromas: staging and management. Ann Otol Rhinol LaryngoI1984;93:322-9.
ADDENDUM Subsequent to the writing and submission of this article, L. S. Weprin and P. T. Siemers reported a case wherein a JNA spontaneously regressed over a 12-year period without any treatment (Spontaneous Regression of Juvenile Nasopharyngeal Angiofibroma, Arch Otolaryngol Head Neck Surg 1991;117:796-9). The JNA had been diagnosed by biopsy in a child 11 years of age. We believe that this case offers further support that JNA, in a minority of cases, can spontaneously involute.
7m WORLD CONGRESS FOR BRONCHOLOGY & BRONCHOESOPHAGOLOGY The 7th World Congresses for Broncology & Bronchoesophagology will be held Sept 28-0ct 2, 1992, at the Mayo Clinic and Mayo Medical Center in Rochester, Minnesota. For further information, contact Udaya B. S. Prakash, MD, Secretary-General & Director, 7th WeB & WCBE, East-18, Mayo Clinic, Rochester, MN 55905.
THE DEAFNESS RESEARCH FOUNDATION 1993 RESEARCH GRANTS AVAILABLE The Deafness Research Foundation invites applications for 1993 grant support of research projects directed to any aspect of the ear, eg, investigation of function, physiology, biochemistry, genetics, anatomy, or pathology. Grant support is given for one year, in an amount that cannot exceed $15,000, but can competitively be renewed for one or two additional years. Applications are reviewed for the scientific merit of the proposed investigations and for their direct or potential clinical value. The deadlines for applications for 1993 grant support are as follows: first year applications should be postmarked by July 15, 1992, and renewal applications should be postmarked by August 15,1992. For information and applications, contact Wesley H. Bradley, MD, Medical Director, The Deafness Research Foundation, 9 East 38th Street, New York, NY 10016; telephone (212) 684-6556; fax (212) 779-2125.
Downloaded from aor.sagepub.com at CARLETON UNIV on June 20, 2015
