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Pleomorphic adenoma originated from the inferior nasal turbinate
Auris Nasus Larynx 30 (2003) 417 /420 www.elsevier.com/locate/anl
Pleomorphic adenoma originated from the inferior nasal turbinate H. Halis Unlu a,*, Onur Celik a, M. Akif Demir b, Gorkem Eskiizmir a a
Department of Otorhinolaryngology, Celal Bayar University, Posta kutusu: 141, TR-45010 Manisa, Turkey b Department of Pathology, Celal Bayar University, Manisa, Turkey Received 27 January 2003; received in revised form 6 May 2003; accepted 16 May 2003
Abstract Although pleomorphic adenoma is the most common benign neoplasm of the salivary glands, it has also been reported to be present in the neck, ear, mediastinum, external nose and nasal cavity. Intranasal localization of this lesion is very rare and mainly originates from the nasal septum. From wherever the lesion originates, the main treatment modality should be surgical. We presented a very rare case of intranasal pleomorphic adenoma originated from the inferior nasal turbinate. Due to the expansile nature of the lesion, a midfacial degloving approach was preferred. # 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: Pleomorphic adenoma; Inferior nasal turbinate; Salivary glands
1. Introduction Salivary gland tumors represent 3% of all head and neck tumors. Among these 85/90% originate from the major salivary glands. Pleomorphic adenoma is the most common benign salivary gland tumor. Although parotid gland constitutes 60% of all pleomorphic adenomas, minor salivary glands constitutes only 8% of them [1]. The potential risk of malignancy transformation of the pleomorphic adenoma is not very high and estimated amount is about 6% [2]. But the risk of malignancy transformation is increased with the delayed diagnosis of the tumor. When the duration of time following tumor formation is less than 5 years, the risk of malignant transformation is about 2%; however, this rate dramatically increases to 10%, when this duration becomes more than 15 years. These kinds of malignant tumors generally have an aggressive prognosis with a 5year mortality rate of about 30/50%. Histopathologically, pleomorphic adenoma possesses a lobular structure with a loose chondromyxoid stroma. The cellular structure is formed of small circular epithelial cells with spindle shaped myoepithelial cells.
* Corresponding author. Tel.: /90-236-237-8367; fax: /90-236237-0213. E-mail address: [email protected] (H.H. Unlu).
Pleomorphic adenomas of minor salivary glands can be seen any location where minor salivary glands are scattered through such as neck, ear, mediastinum, external nose and nasal cavity [3]. However, the lesions detected in nasal cavity are extremely rare. Furthermore, many of the reported intranasal pleomorphic adenomas are originated from the nasal septum. We present a rare case of an intranasal pleomorphic adenoma originated from the inferior nasal turbinate. To our best knowledge, only two other cases have been reported in English literature [4,5]. The clinical, histopathological and radiological properties and treatment modalities of the pleomorphic adenoma originated from inferior turbinate were discussed.
2. Case report A 39-year-old woman presented with a 2-year history of nasal dripping and obstruction. She was previously misdiagnosed as allergic rhinitis and treated with momethasone furoate and fexofenadine. In spite of this medical therapy, her complaints were not relieved. Anterior rhinoscopic examination of the patient revealed a vascularized mass obstructing the right nasal cavity. Endoscopic examination of the right nasal cavity showed that the mass seemed to originate from lateral
0385-8146/03/$ - see front matter # 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0385-8146(03)00090-7
418
H.H. Unlu et al. / Auris Nasus Larynx 30 (2003) 417 /420
nasal wall and protrude to the right nasal cavity. Paranasal computerized tomographic and magnetic resonance imaging evaluations revealed a well circumscribed solid and expansile polypoid lesion which was originated from the inferior turbinate, and obstructed the right nasal cavity. The lesion displaced the lateral nasal wall laterally and did not show any evidence of destruction of the bony structure of the right maxillary sinus (Fig. 1a and b). Later, punch biopsy was made. Histopathological examination revealed that mature respiratory epithelium was covering the surface in the routine sections of formalin fixed-paraffin embedded material and below the epithelium, a tumoral lesion that had biphasic appearance resulting from the admixture of neoplastic epithelium and stroma was seen. Tumoral cells did not show cellular atypia. The epithelial component composed of monotonous round cells was
of ductal nature or forming solid cellular sheets. Also foci of squamous metaplasia were observed. Myoepithelial cells with their clear cytoplasms were the other component of ductal structures. The stroma had myxoid appearance. Neither clear-cut cartilaginous defferantiation nor significant mitotic activity was seen. Depending on the typical findings the lesion was reported as pleomorphic adenoma (benign mixed tumor) (Fig. 2). Due to the expansile nature of the lesion, a midfacial degloving approach was performed. Intraoperatively it was detected that, the mass was originated from the middle 1/3 of the inferior turbinate. Moreover, the mass did not extend into the right maxillary sinus. The mass was removed with total excision of the inferior turbinate. The histopathological examination of the specimen confirmed the preoperative diagnosis with the epithelial and myxoid components. The patient was discharged without any complication 6 days after the surgery and informed about the risk of recurrence. She was followed-up after surgery for 2 years and 6 months.
3. Discussion
Fig. 1. Coronal (a) and axial (b) magnetic resonance imaging show a well circumscribed solid mass 3.5 cm in size, filling the right nasal cavity. The inferior and middle turbinate can not be seen and there is no defect or displacement of the nasal septum. Note a hypoplastic right maxillary sinus and enlarged nasal cavity.
Ferlito [6] established heterotopic salivary gland tissues in head and neck like pituitary gland, external acoustic meatus, nasal cavity, the capsule of thyroid and parathyroid glands, sternoclavicular joint, mandibula and cervical soft tissues. All of these heterotopic salivary gland tissues have a potential development of pleomorphic adenoma. It is suggested that beneath the mature heterotopic salivary gland tissues, pleomorphic adenoma may develop from the embryonic ectodermal epithelial cells or the vomeronasal organ of Jacobson [7]. Compango, Suzuki and Wakami presented their series of pleomorphic adenoma located in nasal cavity [8 /10]. The most common site of origin was the bony cartilaginous septum. Although the vast majority of minor mucous and serous glands are located on the lateral nasal wall, pleomorphic adenomas in the nasal cavity are mostly originated from the nasal septum [11]. However, the reason for that still remains unclear. As previously stated, a careful review of the literature has revealed that inferior turbinate is a highly unusual site for such neoplasms [4,5]. Baraka et al. presented a case of pleomorphic adenoma, originating from the anterior edge of the inferior turbinate, measuring 1 /1.5 cm and obstructing the right nasal cavity [5]. In our case, the tumor was originated from the middle 1/3 of the right inferior turbinate and about 3.5 cm in diameter. Due to its expansile nature, the nasal cavity was completely filled. In Compango, Suzuki and Wakami’s series, the rate of malignancy transformation was 2.5 /10% and had a female predominance [8 /10]. It was stated that the most
H.H. Unlu et al. / Auris Nasus Larynx 30 (2003) 417 /420
419
Fig. 2. Pleomerphic adenoma demonstrating respiratory epithelium on the mucosal surface (thick arrow), borders of the tumor (thin arrows) and squamous differantiation in the tumor, /40, H&E (a); higher magnification of the squamous area (notched arrow), /200, H&E (b); ductular structures and myoepithelial cell rich stroma, /200, H&E (c); ductal lamina containing secretory material (thin arrow) and myoepithelial cells surrounding ductular structures (thick arrows) and myxoid stroma (star), /200, H&E (d).
frequent complaints were nasal obstruction (in 70% of cases) and epistaxis (in 60% of cases). Although the gender, symptomatology and prognosis of the represented case report correlates with the literature, the origin of the tumor is atypical. Wherever the lesion is originated, main treatment modality should be surgical; the total excision of the tumor with tumor negative surgical borders. For this purpose, approaches depend on the size and location and include lateral rhinotomy, transnasal or facial degloving [10,12,13]. However, some intranasal benign tumors, which were successfully treated by endoscopic transnasal surgery have been reported in the literature [14]. Although the postoperative follow-up period was not sufficient, Yiotakis et al. reported a case of pleomorphic adenoma of the nasal septum managed by endoscopic resection [11]. In our case the size of the tumor was not suitable for endoscopic resection. So due to the expansile nature and tendency of the tumor to bleed and to recur, we preferred midfacial degloving approach. This surgical technique has an advantage of wide exposure of the mass and direct approach to the
nasal cavity. Furthermore, it has a cosmetic advantage in comparison to other approaches. In the investigations of Bataskis with 945 tumors originated from the minor salivary glands, he concluded that the minor salivary gland tumors of sinonasal mucosa generally had an agressive prognosis without a relation in their histopathological composition [15]. However, a generalization about all the minor salivary gland tumors of sinonasal mucosa may not be valid for the pleomorphic adenoma. Compango and Wong applied surgical treatment to 40 intranasal pleomorphic adenoma cases and followed them for a 7.5-year period. The rate of recurrence was reported as 5% [8]. According to Krolls and Boyers, intranasal mixed tumors have a relatively low recurrence rate comparing with parotid gland and intraoral mixed tumors [16]. The recurrence rate for parotid mixed tumors was reported in the recent literature ranges between 0 and 43.8% [17]. Some authors proposed that the potential risk of recurrence was decreased in relation to a diminished amount of the myxoid stroma of the tumor [8]. Due to the nonaggressive nature of the tumor, its total excision may result in a
420
H.H. Unlu et al. / Auris Nasus Larynx 30 (2003) 417 /420
lower risk of recurrence. It is well known that insufficient resection will cause a recurrence. The recurrence rate of pleomorphic adenoma depends almost on the adequacy of the primary excision. Recurrence is very high if the tumor is removed by a simple enucleation. This is because small inconspicuous nodules attached by threadlike filaments of neoplastic tissue may be present surrounding the main mass. If the tumor is enucleated, these small remnants will be left behind and will provide the nidus of recurrence. Unfortunately, surgery for recurrent tumor often fails [18]. Most of these recurrences will appear during the first 18 months after surgery, but it is possible to re-emerge over an exceedingly long period (50 years or more) [19]. However, in our reported case, there was no evidence of recurrence after 2.5 years postoperatively; longer follow-up was needed due to the possibility of late recurrences.
References [1] Prager DA, Weiss MH, Buchalter WL, Jacobs M. Pleomorphic adenoma of the nasal cavity. Ann Otol Rhinol Laryngol 1991;100(7):600. [2] Shaheen OH. Benign salivary gland tumours, In: Kerr AG, editors. Scott Brown’s Otolaryngology. 6th ed. London: Butterworth Heinemann, 1997; pp. 5/20/1 /18. [3] Badia L, Weir JN, Robinson AC. Heterotopic pleomorphic adenoma of the external nose. J Laryngol Otol 1996;110:376 /8. [4] Carriero E, Almadori G, Cadoni G. Pleomorphic adenoma of the lower turbinates: clinical case and review of literature. Acta Otorhinolaryngol Ital 1997;17(5):377 /81. [5] Baraka ME, Sadek SA, Salem MH. Pleomorphic adenoma of the inferior turbinate. J Laryngol Otol 1984;98(9):925 /8.
[6] Ferlito A, Baldan M, Andretta M, Blandamura S, Pesavento G, Piazza M. Implantation of parotid pleomorphic adenoma in the upper neck. ORL J Otorhinolaryngol Relat Spec 1991;53(3):165 / 76. [7] Clark M, Fatterpekar GM, Mukherji SK, Buenting J. CT of intranasal pleomorphic adenoma. Neuroradiology 1999;41(8):591 /3. [8] Compango J, Wong RT. Intranasal mixed tumors (pleomorphic adenomas). A clinicopathologic study of 40 cases. Am J Clin Pathol 1977;68:213 /8. [9] Suzuki K, Moribe K, Baba S. A rare case of pleomorphic adenoma of lateral wall of nasal cavity */with special reference of statistical observation of pleomorphic adenoma of nasal cavity in Japan. J Otolaryngol Jpn 1990;93(5):740 /5. [10] Wakami S, Muraoka M, Nakai Y. Two cases of pleomorphic adenoma of the nasal cavity. J Otolaryngol Jpn 1996;99(1):38 /45. [11] Yiotakis I, Dinopoulou D, Ferekidis E, Manolopoulos L, Adamopoulos G. Pleomorphic adenoma of the nose. Rhinology 2001;39:55 /7. [12] Worthington P. Pleomorphic adenoma of the nasal septum. Br J Oral Surg 1977;14(3):245 /52. [13] Castello E, Caligo G, Pallestrini EA. Case report: pleomorphic adenoma of the lateral nasal wall. Acta Otorhinolaryngol Ital 1996;16(5):433 /7. [14] Unlu HH, Unlu Z, Ayhan S, Egrilmez M. Osteochondroma of the posterior nasal septum managed by endoscopic transnasal transseptal approach. J Laryngol Otol 2002;116(11):955 /7. [15] Batsakis JG. Tumors of the head and neck, clinical and pathological considerations. Baltimore: Williams and Wilkins, 1974:84. [16] Krolls SO, Boyers RC. Mixed tumors of salivary glands. Long term follow-up. Cancer 1972;30:276 /81. [17] Ayoub OM, Bhatia K, Mal RH. Pleomorphic adenoma of the parotid gland: is long term follow-up needed. Auris Nasus Larynx 2002;29:283 /5. [18] Malett KJ, Harrison MS. The recurrences of salivary gland tumours. J Laryngol Otol 1971;85:439 /48. [19] Rosai J, editor. Ackermans surgical pathology, vol. I, 8th ed. St Louis, MO: Mosby Year Book, 1996:820 /1.
Pleomorphic adenoma originated from the inferior nasal turbinate H. Halis Unlu a,*, Onur Celik a, M. Akif Demir b, Gorkem Eskiizmir a a
Department of Otorhinolaryngology, Celal Bayar University, Posta kutusu: 141, TR-45010 Manisa, Turkey b Department of Pathology, Celal Bayar University, Manisa, Turkey Received 27 January 2003; received in revised form 6 May 2003; accepted 16 May 2003
Abstract Although pleomorphic adenoma is the most common benign neoplasm of the salivary glands, it has also been reported to be present in the neck, ear, mediastinum, external nose and nasal cavity. Intranasal localization of this lesion is very rare and mainly originates from the nasal septum. From wherever the lesion originates, the main treatment modality should be surgical. We presented a very rare case of intranasal pleomorphic adenoma originated from the inferior nasal turbinate. Due to the expansile nature of the lesion, a midfacial degloving approach was preferred. # 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: Pleomorphic adenoma; Inferior nasal turbinate; Salivary glands
1. Introduction Salivary gland tumors represent 3% of all head and neck tumors. Among these 85/90% originate from the major salivary glands. Pleomorphic adenoma is the most common benign salivary gland tumor. Although parotid gland constitutes 60% of all pleomorphic adenomas, minor salivary glands constitutes only 8% of them [1]. The potential risk of malignancy transformation of the pleomorphic adenoma is not very high and estimated amount is about 6% [2]. But the risk of malignancy transformation is increased with the delayed diagnosis of the tumor. When the duration of time following tumor formation is less than 5 years, the risk of malignant transformation is about 2%; however, this rate dramatically increases to 10%, when this duration becomes more than 15 years. These kinds of malignant tumors generally have an aggressive prognosis with a 5year mortality rate of about 30/50%. Histopathologically, pleomorphic adenoma possesses a lobular structure with a loose chondromyxoid stroma. The cellular structure is formed of small circular epithelial cells with spindle shaped myoepithelial cells.
* Corresponding author. Tel.: /90-236-237-8367; fax: /90-236237-0213. E-mail address: [email protected] (H.H. Unlu).
Pleomorphic adenomas of minor salivary glands can be seen any location where minor salivary glands are scattered through such as neck, ear, mediastinum, external nose and nasal cavity [3]. However, the lesions detected in nasal cavity are extremely rare. Furthermore, many of the reported intranasal pleomorphic adenomas are originated from the nasal septum. We present a rare case of an intranasal pleomorphic adenoma originated from the inferior nasal turbinate. To our best knowledge, only two other cases have been reported in English literature [4,5]. The clinical, histopathological and radiological properties and treatment modalities of the pleomorphic adenoma originated from inferior turbinate were discussed.
2. Case report A 39-year-old woman presented with a 2-year history of nasal dripping and obstruction. She was previously misdiagnosed as allergic rhinitis and treated with momethasone furoate and fexofenadine. In spite of this medical therapy, her complaints were not relieved. Anterior rhinoscopic examination of the patient revealed a vascularized mass obstructing the right nasal cavity. Endoscopic examination of the right nasal cavity showed that the mass seemed to originate from lateral
0385-8146/03/$ - see front matter # 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0385-8146(03)00090-7
418
H.H. Unlu et al. / Auris Nasus Larynx 30 (2003) 417 /420
nasal wall and protrude to the right nasal cavity. Paranasal computerized tomographic and magnetic resonance imaging evaluations revealed a well circumscribed solid and expansile polypoid lesion which was originated from the inferior turbinate, and obstructed the right nasal cavity. The lesion displaced the lateral nasal wall laterally and did not show any evidence of destruction of the bony structure of the right maxillary sinus (Fig. 1a and b). Later, punch biopsy was made. Histopathological examination revealed that mature respiratory epithelium was covering the surface in the routine sections of formalin fixed-paraffin embedded material and below the epithelium, a tumoral lesion that had biphasic appearance resulting from the admixture of neoplastic epithelium and stroma was seen. Tumoral cells did not show cellular atypia. The epithelial component composed of monotonous round cells was
of ductal nature or forming solid cellular sheets. Also foci of squamous metaplasia were observed. Myoepithelial cells with their clear cytoplasms were the other component of ductal structures. The stroma had myxoid appearance. Neither clear-cut cartilaginous defferantiation nor significant mitotic activity was seen. Depending on the typical findings the lesion was reported as pleomorphic adenoma (benign mixed tumor) (Fig. 2). Due to the expansile nature of the lesion, a midfacial degloving approach was performed. Intraoperatively it was detected that, the mass was originated from the middle 1/3 of the inferior turbinate. Moreover, the mass did not extend into the right maxillary sinus. The mass was removed with total excision of the inferior turbinate. The histopathological examination of the specimen confirmed the preoperative diagnosis with the epithelial and myxoid components. The patient was discharged without any complication 6 days after the surgery and informed about the risk of recurrence. She was followed-up after surgery for 2 years and 6 months.
3. Discussion
Fig. 1. Coronal (a) and axial (b) magnetic resonance imaging show a well circumscribed solid mass 3.5 cm in size, filling the right nasal cavity. The inferior and middle turbinate can not be seen and there is no defect or displacement of the nasal septum. Note a hypoplastic right maxillary sinus and enlarged nasal cavity.
Ferlito [6] established heterotopic salivary gland tissues in head and neck like pituitary gland, external acoustic meatus, nasal cavity, the capsule of thyroid and parathyroid glands, sternoclavicular joint, mandibula and cervical soft tissues. All of these heterotopic salivary gland tissues have a potential development of pleomorphic adenoma. It is suggested that beneath the mature heterotopic salivary gland tissues, pleomorphic adenoma may develop from the embryonic ectodermal epithelial cells or the vomeronasal organ of Jacobson [7]. Compango, Suzuki and Wakami presented their series of pleomorphic adenoma located in nasal cavity [8 /10]. The most common site of origin was the bony cartilaginous septum. Although the vast majority of minor mucous and serous glands are located on the lateral nasal wall, pleomorphic adenomas in the nasal cavity are mostly originated from the nasal septum [11]. However, the reason for that still remains unclear. As previously stated, a careful review of the literature has revealed that inferior turbinate is a highly unusual site for such neoplasms [4,5]. Baraka et al. presented a case of pleomorphic adenoma, originating from the anterior edge of the inferior turbinate, measuring 1 /1.5 cm and obstructing the right nasal cavity [5]. In our case, the tumor was originated from the middle 1/3 of the right inferior turbinate and about 3.5 cm in diameter. Due to its expansile nature, the nasal cavity was completely filled. In Compango, Suzuki and Wakami’s series, the rate of malignancy transformation was 2.5 /10% and had a female predominance [8 /10]. It was stated that the most
H.H. Unlu et al. / Auris Nasus Larynx 30 (2003) 417 /420
419
Fig. 2. Pleomerphic adenoma demonstrating respiratory epithelium on the mucosal surface (thick arrow), borders of the tumor (thin arrows) and squamous differantiation in the tumor, /40, H&E (a); higher magnification of the squamous area (notched arrow), /200, H&E (b); ductular structures and myoepithelial cell rich stroma, /200, H&E (c); ductal lamina containing secretory material (thin arrow) and myoepithelial cells surrounding ductular structures (thick arrows) and myxoid stroma (star), /200, H&E (d).
frequent complaints were nasal obstruction (in 70% of cases) and epistaxis (in 60% of cases). Although the gender, symptomatology and prognosis of the represented case report correlates with the literature, the origin of the tumor is atypical. Wherever the lesion is originated, main treatment modality should be surgical; the total excision of the tumor with tumor negative surgical borders. For this purpose, approaches depend on the size and location and include lateral rhinotomy, transnasal or facial degloving [10,12,13]. However, some intranasal benign tumors, which were successfully treated by endoscopic transnasal surgery have been reported in the literature [14]. Although the postoperative follow-up period was not sufficient, Yiotakis et al. reported a case of pleomorphic adenoma of the nasal septum managed by endoscopic resection [11]. In our case the size of the tumor was not suitable for endoscopic resection. So due to the expansile nature and tendency of the tumor to bleed and to recur, we preferred midfacial degloving approach. This surgical technique has an advantage of wide exposure of the mass and direct approach to the
nasal cavity. Furthermore, it has a cosmetic advantage in comparison to other approaches. In the investigations of Bataskis with 945 tumors originated from the minor salivary glands, he concluded that the minor salivary gland tumors of sinonasal mucosa generally had an agressive prognosis without a relation in their histopathological composition [15]. However, a generalization about all the minor salivary gland tumors of sinonasal mucosa may not be valid for the pleomorphic adenoma. Compango and Wong applied surgical treatment to 40 intranasal pleomorphic adenoma cases and followed them for a 7.5-year period. The rate of recurrence was reported as 5% [8]. According to Krolls and Boyers, intranasal mixed tumors have a relatively low recurrence rate comparing with parotid gland and intraoral mixed tumors [16]. The recurrence rate for parotid mixed tumors was reported in the recent literature ranges between 0 and 43.8% [17]. Some authors proposed that the potential risk of recurrence was decreased in relation to a diminished amount of the myxoid stroma of the tumor [8]. Due to the nonaggressive nature of the tumor, its total excision may result in a
420
H.H. Unlu et al. / Auris Nasus Larynx 30 (2003) 417 /420
lower risk of recurrence. It is well known that insufficient resection will cause a recurrence. The recurrence rate of pleomorphic adenoma depends almost on the adequacy of the primary excision. Recurrence is very high if the tumor is removed by a simple enucleation. This is because small inconspicuous nodules attached by threadlike filaments of neoplastic tissue may be present surrounding the main mass. If the tumor is enucleated, these small remnants will be left behind and will provide the nidus of recurrence. Unfortunately, surgery for recurrent tumor often fails [18]. Most of these recurrences will appear during the first 18 months after surgery, but it is possible to re-emerge over an exceedingly long period (50 years or more) [19]. However, in our reported case, there was no evidence of recurrence after 2.5 years postoperatively; longer follow-up was needed due to the possibility of late recurrences.
References [1] Prager DA, Weiss MH, Buchalter WL, Jacobs M. Pleomorphic adenoma of the nasal cavity. Ann Otol Rhinol Laryngol 1991;100(7):600. [2] Shaheen OH. Benign salivary gland tumours, In: Kerr AG, editors. Scott Brown’s Otolaryngology. 6th ed. London: Butterworth Heinemann, 1997; pp. 5/20/1 /18. [3] Badia L, Weir JN, Robinson AC. Heterotopic pleomorphic adenoma of the external nose. J Laryngol Otol 1996;110:376 /8. [4] Carriero E, Almadori G, Cadoni G. Pleomorphic adenoma of the lower turbinates: clinical case and review of literature. Acta Otorhinolaryngol Ital 1997;17(5):377 /81. [5] Baraka ME, Sadek SA, Salem MH. Pleomorphic adenoma of the inferior turbinate. J Laryngol Otol 1984;98(9):925 /8.
[6] Ferlito A, Baldan M, Andretta M, Blandamura S, Pesavento G, Piazza M. Implantation of parotid pleomorphic adenoma in the upper neck. ORL J Otorhinolaryngol Relat Spec 1991;53(3):165 / 76. [7] Clark M, Fatterpekar GM, Mukherji SK, Buenting J. CT of intranasal pleomorphic adenoma. Neuroradiology 1999;41(8):591 /3. [8] Compango J, Wong RT. Intranasal mixed tumors (pleomorphic adenomas). A clinicopathologic study of 40 cases. Am J Clin Pathol 1977;68:213 /8. [9] Suzuki K, Moribe K, Baba S. A rare case of pleomorphic adenoma of lateral wall of nasal cavity */with special reference of statistical observation of pleomorphic adenoma of nasal cavity in Japan. J Otolaryngol Jpn 1990;93(5):740 /5. [10] Wakami S, Muraoka M, Nakai Y. Two cases of pleomorphic adenoma of the nasal cavity. J Otolaryngol Jpn 1996;99(1):38 /45. [11] Yiotakis I, Dinopoulou D, Ferekidis E, Manolopoulos L, Adamopoulos G. Pleomorphic adenoma of the nose. Rhinology 2001;39:55 /7. [12] Worthington P. Pleomorphic adenoma of the nasal septum. Br J Oral Surg 1977;14(3):245 /52. [13] Castello E, Caligo G, Pallestrini EA. Case report: pleomorphic adenoma of the lateral nasal wall. Acta Otorhinolaryngol Ital 1996;16(5):433 /7. [14] Unlu HH, Unlu Z, Ayhan S, Egrilmez M. Osteochondroma of the posterior nasal septum managed by endoscopic transnasal transseptal approach. J Laryngol Otol 2002;116(11):955 /7. [15] Batsakis JG. Tumors of the head and neck, clinical and pathological considerations. Baltimore: Williams and Wilkins, 1974:84. [16] Krolls SO, Boyers RC. Mixed tumors of salivary glands. Long term follow-up. Cancer 1972;30:276 /81. [17] Ayoub OM, Bhatia K, Mal RH. Pleomorphic adenoma of the parotid gland: is long term follow-up needed. Auris Nasus Larynx 2002;29:283 /5. [18] Malett KJ, Harrison MS. The recurrences of salivary gland tumours. J Laryngol Otol 1971;85:439 /48. [19] Rosai J, editor. Ackermans surgical pathology, vol. I, 8th ed. St Louis, MO: Mosby Year Book, 1996:820 /1.