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British Journal of Oral and Maxillofacial Surgery 53 (2015) 526–528
Multiple, synchronous, unilateral parotid adenomas: a case series L. Andrews ∗ , N. Shah Queens Hospital, Rom Valley Way, Romford, Essex RM7 0AG, United Kingdom Accepted 5 March 2015 Available online 20 April 2015
Abstract Most tumours of the major salivary glands are single and unilateral, and involve the parotid. It is uncommon for synchronous, multifocal tumours of the same histological type to affect one gland, and cases with multiple types are rare. Extracapsular dissection, an established technique for the safe removal of benign tumours of the parotid gland, has low rates of morbidity and recurrence, but relies on careful preoperative assessment and selection of cases. In a consecutive series of 70 cases of extracapsular dissection over 5 years by one surgeon, we found a 4% incidence (n = 3) of synchronous, unilateral, multiple adenomas in the parotid gland. © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Unilateral; Synchronous; Parotid; Adenomas
Introduction Multiple, unilateral, synchronous, parotid adenomas are rare in patients with no history of previous trauma or surgery,1 and these primary parotid tumours are usually of one histological type.2 When there are different histological types, the most commonly reported combination is Warthin’s tumour and pleomorphic adenoma.3 Pleomorphic adenomas associated with other tumours are even less common.3
Case 1 A 55-year-old white man presented with a one-month history of an asymptomatic swelling of the left preauricular area. His previous medical history was unremarkable and there was no history of parotid surgery or trauma. He had smoked 20 cigarettes a day for the past 29 years, and consumed 2 units of alcohol/week. Clinical examination showed ∗
Corresponding author. Tel.: +44 7821295188. E-mail address: [email protected] (L. Andrews).
a mobile swelling of the left inferior lobe of the parotid gland about 1 cm in diameter. The cranial nerves were intact. Magnetic resonance imaging (MRI) showed a well-defined lesion with high signal intensity within the superficial part of the left parotid measuring 10 mm in diameter, and evidence of another well-defined space-occupying lesion in the left parapharyngeal space 2.7 cm × 1.7 cm in diameter (Fig. 1). Analysis of an ultrasound-guided fine needle aspirate (FNA) of the superficial lesion was suggestive of a pleomorphic adenoma. Treatment included extracapsular dissection of both lesions with preservation of the facial nerve. Histopathological examination confirmed that both had been completely excised and were mixed pleomorphic adenomas. Three years after operation there is no evidence of recurrence and the facial nerve functions normally.
Case 2 A 55-year-old black man presented to the accident and emergency (A&E) department with a 6-month history of a swelling
http://dx.doi.org/10.1016/j.bjoms.2015.03.003 0266-4356/© 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
L. Andrews, N. Shah / British Journal of Oral and Maxillofacial Surgery 53 (2015) 526–528
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Fig. 3. Magnetic resonance image showing 2 pleomorphic adenomas in the right parotid gland. Fig. 1. Magnetic resonance image showing 2 pleomorphic adenomas in the left parotid gland.
Case 3 at the left angle of the mandible and localised pain for the last 2 weeks. Previous medical and social histories were unremarkable and he had had no previous parotid surgery or trauma. Clinical examination showed a mobile, superficial lump at the left angle of the mandible about 1.5 cm in diameter. The cranial nerves were intact. MRI showed 3 separate nodules in the superficial lobe of the left parotid measuring 1.5, 1.3, and 1.6 cm (Fig. 2). They all showed similar features with an increased signal on T2-weighted and short TI inversion recovery (STIR) images, and a mildly heterogeneous central area. Analysis of an ultrasound-guided FNA was suggestive of a salivary neoplasm but was not specific. All the lesions were excised after partial superficial parotidectomy of the left gland with preservation of the facial nerve. The histopathological results showed 2 pleomorphic adenomas with a classic mixed appearance, and a basal cell adenoma of mixed solid and trabecular type. All were completely excised. Four years postoperatively there is no evidence of recurrence and facial nerve function is normal.
A 45-year-old white man presented with a 12-month history of an asymptomatic swelling around his right parotid gland. His previous medical history was unremarkable. He had smoked 20 cigarettes a day for 30 years and consumed 30 units of alcohol/week. There was no history of previous parotid surgery or trauma. Clinical examination showed a mobile and superficial swelling about 2 cm in diameter. The cranial nerves were intact. Ultrasound-guided FNA was suggestive of an adenolymphoma (Warthin’s tumour) and MRI showed 2 discrete tumours similar in appearance within the tail of the right parotid (Fig. 3). He had a right-sided extracapsular dissection to remove both tumours and the facial nerve was preserved. Histopathological analysis showed 2 completely excised pleomorphic adenomas. The more superficial tumour had a myxoid architecture whereas the deeper tumour had the mixed, classic appearance of a pleomorphic adenoma. Four years postoperatively there is no evidence of recurrence and facial nerve function is normal.
Fig. 2. Magnetic resonance image showing the 3 lesions in the left parotid gland in different sections.
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L. Andrews, N. Shah / British Journal of Oral and Maxillofacial Surgery 53 (2015) 526–528
Discussion Most tumours of the major salivary glands are single and unilateral, and involve the parotid.2 Synchronous, multifocal tumours of the same histological type are uncommon, and cases with multiple types are rare.4 Almost all unilateral, multifocal salivary tumours occur in the parotid gland.5 The incidence of unilateral, synchronous, distinct neoplasms make up less than 1% of parotid tumours (range 0.2%–0.7%),4 and they are usually benign and of the same histological type.5 Most unilateral cases are adenolymphomas, which account for 6%–12% of all such neoplasms.1 Pleomorphic adenoma is the most common benign tumour of the salivary glands and is most often found in the parotid.6 Primary, multiple, pleomorphic adenomas in the parotid are rare and have a reported incidence of 0.14%–0.6%,6,7 which differs from our findings (3/70, 4%). Pleomorphic adenomas can become multifocal, particularly when they recur postoperatively (and particularly when the tumour has been incompletely excised) or as a result of trauma,5 but this had occurred in none of our patients. The pathogenesis of primary, unilateral, multifocal, pleomorphic adenomas is unclear.5 Some authors suggest that multiple parasitic nodules arise when they become detached from a single tumour – for example, after trauma, while others suggest that multiple tumours would show a heterogeneous clonal origin.5 Our series is interesting as it includes 3 cases of unilateral synchronous pleomorphic adenomas and is, to our knowledge, the first report of multiple pleomorphic adenomas and a basal cell adenoma in the parotid gland. In all cases, had special investigations not been done, the use of conservative surgical dissection would have resulted in disease being missed preoperatively. It also suggests that the incidence of synchronous tumours may be higher than was previously thought.1 The use of preoperative imaging in the investigation of a parotid lesion can also show other neoplasms8 and can reduce the need for further operations and their associated complications.1 The combination of ultrasound-guided FNA and MRI seems to improve diagnostic accuracy.1 MRI is the imaging of choice because of its superior ability to differentiate soft tissue. Scans can provide clues about histological type – for example, a pleomorphic adenoma is commonly round and well circumscribed with a smooth surface.9 It usually has areas of bright signal on T2weighted images and a low intensity rim that indicates the capsule.10 Ultrasound-guided FNAC is considered a simple, cheap test with few complications, but it has limited diagnostic value for parotid disease because of its low sensitivity.11 However, its high specificity and high negative predictive value make it a more accurate test in cases of benign disease,11
and it has an accuracy of 85%–97% in establishing whether a tumour is benign or malignant. 7 The deep lobe of the parotid is not clearly seen on ultrasound as it is concealed by the mandible,7 and our case series shows that use of ultrasoundguided FNAC alone for diagnosis is not reliable. However, its use is still promoted as part of a diagnostic investigation as it can help to plan the extent of surgical treatment when done by an experienced radiologist and analysed by a cytopathologist familiar with diseases of the salivary glands.11 Our patients continue to be followed up and imaging is done if necessary.
Conflict of interest We have no conflicts of interest
Ethics statement/confirmation of patient permission No ethics was required or patient permission.
References 1. Zeebregt CJ, Mastboom WJ, van Noort G, et al. Synchronous tumours of the unilateral parotid gland: rare or undetected? J Craniomaxillofac Surg 2003;31:62–6. 2. Van Egmond SL, de Leng WW, Morsink FH, et al. Monoclonal origin of primary unilateral multifocal pleomorphic adenoma of the parotid gland. Hum Pathol 2013;44:923–6. 3. Lefor AT, Ord RA. Multiple synchronous bilateral Warthin’s tumours of the parotid glands with pleomorphic adenoma. Case report and review of the literature. Oral Surg Oral Med Oral Pathol 1993;76:319–24. 4. Schilling JA, Block BL, Speigel JC. Synchronous unilateral parotid neoplasms of different histologic types. Head Neck 1989;11:179–83. 5. Tanaka S, Tabuchi K, Oikawa K, et al. Synchronous unilateral parotid gland neoplasms of three different histological types. Auris Nasus Larynx 2007;34:263–6. 6. Miliauskas JR, Hunt JL. Primary unilateral multifocal pleomorphic adenoma of the parotid gland: molecular assessment and literature review. Head Neck Pathol 2008;2:339–44. 7. De Ru JA, van Leeuwen MS, van Benthem PP, et al. Do magnetic resonance imaging and ultrasound add anything to the preoperative workup of parotid gland tumours? J Oral Maxillofac Surg 2007;65:945–52. 8. Coombes DM, Kaddour R, Shah N. Synchronous unilateral pleomorphic adenomas in the parotid gland: report of a case. Br J Oral Maxillofac Surg 2009;47:155–6. 9. Espinoza S, Halimi P. Interpretation pearls for MR imaging of parotid gland tumor. Eur Ann Otorhinolaryngol Head Neck Dis 2013;130(1):30–5. 10. Kinoshita T, Ishii K, Naganuma H, et al. MR imaging findings of parotid tumors with pathologic diagnostic clues: a pictorial essay. Clin Imaging 2004;28:93–101. 11. Zerpa Zerpa V, Cuesta Gonzáles MT, Agostini Porras G, et al. Diagnostic accuracy of FNAC in parotid tumours. Acta Otorrinolaringol Esp 2014;65:157–61 [in Spanish].
British Journal of Oral and Maxillofacial Surgery 53 (2015) 526–528
Multiple, synchronous, unilateral parotid adenomas: a case series L. Andrews ∗ , N. Shah Queens Hospital, Rom Valley Way, Romford, Essex RM7 0AG, United Kingdom Accepted 5 March 2015 Available online 20 April 2015
Abstract Most tumours of the major salivary glands are single and unilateral, and involve the parotid. It is uncommon for synchronous, multifocal tumours of the same histological type to affect one gland, and cases with multiple types are rare. Extracapsular dissection, an established technique for the safe removal of benign tumours of the parotid gland, has low rates of morbidity and recurrence, but relies on careful preoperative assessment and selection of cases. In a consecutive series of 70 cases of extracapsular dissection over 5 years by one surgeon, we found a 4% incidence (n = 3) of synchronous, unilateral, multiple adenomas in the parotid gland. © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Unilateral; Synchronous; Parotid; Adenomas
Introduction Multiple, unilateral, synchronous, parotid adenomas are rare in patients with no history of previous trauma or surgery,1 and these primary parotid tumours are usually of one histological type.2 When there are different histological types, the most commonly reported combination is Warthin’s tumour and pleomorphic adenoma.3 Pleomorphic adenomas associated with other tumours are even less common.3
Case 1 A 55-year-old white man presented with a one-month history of an asymptomatic swelling of the left preauricular area. His previous medical history was unremarkable and there was no history of parotid surgery or trauma. He had smoked 20 cigarettes a day for the past 29 years, and consumed 2 units of alcohol/week. Clinical examination showed ∗
Corresponding author. Tel.: +44 7821295188. E-mail address: [email protected] (L. Andrews).
a mobile swelling of the left inferior lobe of the parotid gland about 1 cm in diameter. The cranial nerves were intact. Magnetic resonance imaging (MRI) showed a well-defined lesion with high signal intensity within the superficial part of the left parotid measuring 10 mm in diameter, and evidence of another well-defined space-occupying lesion in the left parapharyngeal space 2.7 cm × 1.7 cm in diameter (Fig. 1). Analysis of an ultrasound-guided fine needle aspirate (FNA) of the superficial lesion was suggestive of a pleomorphic adenoma. Treatment included extracapsular dissection of both lesions with preservation of the facial nerve. Histopathological examination confirmed that both had been completely excised and were mixed pleomorphic adenomas. Three years after operation there is no evidence of recurrence and the facial nerve functions normally.
Case 2 A 55-year-old black man presented to the accident and emergency (A&E) department with a 6-month history of a swelling
http://dx.doi.org/10.1016/j.bjoms.2015.03.003 0266-4356/© 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
L. Andrews, N. Shah / British Journal of Oral and Maxillofacial Surgery 53 (2015) 526–528
527
Fig. 3. Magnetic resonance image showing 2 pleomorphic adenomas in the right parotid gland. Fig. 1. Magnetic resonance image showing 2 pleomorphic adenomas in the left parotid gland.
Case 3 at the left angle of the mandible and localised pain for the last 2 weeks. Previous medical and social histories were unremarkable and he had had no previous parotid surgery or trauma. Clinical examination showed a mobile, superficial lump at the left angle of the mandible about 1.5 cm in diameter. The cranial nerves were intact. MRI showed 3 separate nodules in the superficial lobe of the left parotid measuring 1.5, 1.3, and 1.6 cm (Fig. 2). They all showed similar features with an increased signal on T2-weighted and short TI inversion recovery (STIR) images, and a mildly heterogeneous central area. Analysis of an ultrasound-guided FNA was suggestive of a salivary neoplasm but was not specific. All the lesions were excised after partial superficial parotidectomy of the left gland with preservation of the facial nerve. The histopathological results showed 2 pleomorphic adenomas with a classic mixed appearance, and a basal cell adenoma of mixed solid and trabecular type. All were completely excised. Four years postoperatively there is no evidence of recurrence and facial nerve function is normal.
A 45-year-old white man presented with a 12-month history of an asymptomatic swelling around his right parotid gland. His previous medical history was unremarkable. He had smoked 20 cigarettes a day for 30 years and consumed 30 units of alcohol/week. There was no history of previous parotid surgery or trauma. Clinical examination showed a mobile and superficial swelling about 2 cm in diameter. The cranial nerves were intact. Ultrasound-guided FNA was suggestive of an adenolymphoma (Warthin’s tumour) and MRI showed 2 discrete tumours similar in appearance within the tail of the right parotid (Fig. 3). He had a right-sided extracapsular dissection to remove both tumours and the facial nerve was preserved. Histopathological analysis showed 2 completely excised pleomorphic adenomas. The more superficial tumour had a myxoid architecture whereas the deeper tumour had the mixed, classic appearance of a pleomorphic adenoma. Four years postoperatively there is no evidence of recurrence and facial nerve function is normal.
Fig. 2. Magnetic resonance image showing the 3 lesions in the left parotid gland in different sections.
528
L. Andrews, N. Shah / British Journal of Oral and Maxillofacial Surgery 53 (2015) 526–528
Discussion Most tumours of the major salivary glands are single and unilateral, and involve the parotid.2 Synchronous, multifocal tumours of the same histological type are uncommon, and cases with multiple types are rare.4 Almost all unilateral, multifocal salivary tumours occur in the parotid gland.5 The incidence of unilateral, synchronous, distinct neoplasms make up less than 1% of parotid tumours (range 0.2%–0.7%),4 and they are usually benign and of the same histological type.5 Most unilateral cases are adenolymphomas, which account for 6%–12% of all such neoplasms.1 Pleomorphic adenoma is the most common benign tumour of the salivary glands and is most often found in the parotid.6 Primary, multiple, pleomorphic adenomas in the parotid are rare and have a reported incidence of 0.14%–0.6%,6,7 which differs from our findings (3/70, 4%). Pleomorphic adenomas can become multifocal, particularly when they recur postoperatively (and particularly when the tumour has been incompletely excised) or as a result of trauma,5 but this had occurred in none of our patients. The pathogenesis of primary, unilateral, multifocal, pleomorphic adenomas is unclear.5 Some authors suggest that multiple parasitic nodules arise when they become detached from a single tumour – for example, after trauma, while others suggest that multiple tumours would show a heterogeneous clonal origin.5 Our series is interesting as it includes 3 cases of unilateral synchronous pleomorphic adenomas and is, to our knowledge, the first report of multiple pleomorphic adenomas and a basal cell adenoma in the parotid gland. In all cases, had special investigations not been done, the use of conservative surgical dissection would have resulted in disease being missed preoperatively. It also suggests that the incidence of synchronous tumours may be higher than was previously thought.1 The use of preoperative imaging in the investigation of a parotid lesion can also show other neoplasms8 and can reduce the need for further operations and their associated complications.1 The combination of ultrasound-guided FNA and MRI seems to improve diagnostic accuracy.1 MRI is the imaging of choice because of its superior ability to differentiate soft tissue. Scans can provide clues about histological type – for example, a pleomorphic adenoma is commonly round and well circumscribed with a smooth surface.9 It usually has areas of bright signal on T2weighted images and a low intensity rim that indicates the capsule.10 Ultrasound-guided FNAC is considered a simple, cheap test with few complications, but it has limited diagnostic value for parotid disease because of its low sensitivity.11 However, its high specificity and high negative predictive value make it a more accurate test in cases of benign disease,11
and it has an accuracy of 85%–97% in establishing whether a tumour is benign or malignant. 7 The deep lobe of the parotid is not clearly seen on ultrasound as it is concealed by the mandible,7 and our case series shows that use of ultrasoundguided FNAC alone for diagnosis is not reliable. However, its use is still promoted as part of a diagnostic investigation as it can help to plan the extent of surgical treatment when done by an experienced radiologist and analysed by a cytopathologist familiar with diseases of the salivary glands.11 Our patients continue to be followed up and imaging is done if necessary.
Conflict of interest We have no conflicts of interest
Ethics statement/confirmation of patient permission No ethics was required or patient permission.
References 1. Zeebregt CJ, Mastboom WJ, van Noort G, et al. Synchronous tumours of the unilateral parotid gland: rare or undetected? J Craniomaxillofac Surg 2003;31:62–6. 2. Van Egmond SL, de Leng WW, Morsink FH, et al. Monoclonal origin of primary unilateral multifocal pleomorphic adenoma of the parotid gland. Hum Pathol 2013;44:923–6. 3. Lefor AT, Ord RA. Multiple synchronous bilateral Warthin’s tumours of the parotid glands with pleomorphic adenoma. Case report and review of the literature. Oral Surg Oral Med Oral Pathol 1993;76:319–24. 4. Schilling JA, Block BL, Speigel JC. Synchronous unilateral parotid neoplasms of different histologic types. Head Neck 1989;11:179–83. 5. Tanaka S, Tabuchi K, Oikawa K, et al. Synchronous unilateral parotid gland neoplasms of three different histological types. Auris Nasus Larynx 2007;34:263–6. 6. Miliauskas JR, Hunt JL. Primary unilateral multifocal pleomorphic adenoma of the parotid gland: molecular assessment and literature review. Head Neck Pathol 2008;2:339–44. 7. De Ru JA, van Leeuwen MS, van Benthem PP, et al. Do magnetic resonance imaging and ultrasound add anything to the preoperative workup of parotid gland tumours? J Oral Maxillofac Surg 2007;65:945–52. 8. Coombes DM, Kaddour R, Shah N. Synchronous unilateral pleomorphic adenomas in the parotid gland: report of a case. Br J Oral Maxillofac Surg 2009;47:155–6. 9. Espinoza S, Halimi P. Interpretation pearls for MR imaging of parotid gland tumor. Eur Ann Otorhinolaryngol Head Neck Dis 2013;130(1):30–5. 10. Kinoshita T, Ishii K, Naganuma H, et al. MR imaging findings of parotid tumors with pathologic diagnostic clues: a pictorial essay. Clin Imaging 2004;28:93–101. 11. Zerpa Zerpa V, Cuesta Gonzáles MT, Agostini Porras G, et al. Diagnostic accuracy of FNAC in parotid tumours. Acta Otorrinolaringol Esp 2014;65:157–61 [in Spanish].
