Clinical Review & Education
Clinical Challenge | RADIOLOGY
Left Parotid Gland Swelling in an Infant Kenny F. Lin, MD; Marc A. Cohen, MD; Vikash K. Modi, MD
A T1-Weighted sequence
B
C
D Left preauricular in situ during surgical excision
Short T1 inversion recovery sequence
T1-Weighted sequence postcontrast with fat suppression
Figure. Magnetic resonance images of a patient with a left preauricular mass of the superficial parotid lobe.
An infant girl presented to the pediatric otolaryngology clinic with a 2-month history of an enlarging left preauricular mass. The parents first noticed a pea-sized nodule in front of her left ear that was now 3 cm, soft, mobile, and nontender, without overlying skin changes or facial nerve impairment. The infant was otherwise well without fevers, feeding well, and growing appropriQuiz at ately. Her mother had a full-term vaginal delivery withjamaotolaryngology.com out complications and a medical history that was notable only for gastroesophageal reflux disease treated with ranitidine. Ultrasonography showed a 2.2 × 3.0-cm solid nodule. The patient was then referred for magnetic resonance imaging (MRI) with contrast, which showed a 2.9 × 1.6 × 2.3-cm mass with a welldefined capsule arising from within the superficial left parotid gland. The mass was largely of fat signal intensity on both T1-weighted (Figure, A) and T2-weighted sequences with heterogeneous soft-tissue enhancement on T1 post-contrast (Figure, B). The mass also suppressed relatively uniformly on short T1 inversion recovery (STIR) sequence (Figure, C). The Figure, D, shows the mass in situ during surgical excision with facial nerve monitoring.
jamaotolaryngology.com
WHAT IS YOUR DIAGNOSIS?
A. Parotitis B. Lipoma C. Sialolipoma D. Hemangioma
(Reprinted) JAMA Otolaryngology–Head & Neck Surgery August 2015 Volume 141, Number 8
Copyright 2015 American Medical Association. All rights reserved.
Downloaded From: http://archotol.jamanetwork.com/ by a Rutgers University Libraries User on 03/08/2016
765
Clinical Review & Education Clinical Challenge
Diagnosis C. Sialolipoma
Discussion Cytologic findings from fine-needle aspiration suggested a lipomatous lesion without definitive lipoblasts. The case was discussed during a multidisciplinary head and neck tumor board meeting. The team decided to proceed with surgical resection with facial nerve monitoring. A well-circumscribed mass embedded superficially in the parotid tissue and lateral to the facial nerve was excised without complication. Histopathologic examination showed a tan, lobulated soft mass most consistent with sialolipoma. At follow-up, facial nerve function was preserved without recurrence of the mass. Sialolipomas are benign lipomatous tumors arising from salivary gland tissue and have only recently been recognized as a distinct entity. Nagao et al 1 described sialolipomas as wellencapsulated tumors comprised primarily of mature adipose tissue admixed with normal salivary glandular tissue. They arise from both major and minor salivary glands and are theorized to be lipomas with secondary entrapment of salivary gland elements.1 A literature review found 36 total cases with 14 cases involving the parotid gland.2-8 Lipomatous lesions are found in 0.5% to 1% of all parotid gland tumors, and most occur in males during late adulthood (mean age, 55 years).1,8 Sialolipomas in the parotid gland, however, are a subset with equal incidence between sexes. The reported age range is 6 weeks to 77 years, with 90% of cases occurring in adulthood.2-7 The most common cause of parotid gland swelling in childhood is parotitis, and the most common congenital tumor is hemangioma.4 After ultrasonography demonstrated a solid nodule in the left parotid gland, an MRI scan was obtained. Adipose tissue is bright on both T1- and T2-weighted sequences, does not restrict diffusion on diffusion weighted imaging (appearing hypointense), and is dark on fatsuppressed STIR sequences.1 In this case, the mass was largely of fat signal intensity on both T1 (Figure, A) and T2 images, enhanced hetARTICLE INFORMATION Author Affiliations: Department of Otorhinolaryngology–Head and Neck Surgery, Weill Cornell Medical College, New York, New York. Corresponding Author: Kenny F. Lin, MD, Department of Otorhinolaryngology–Head and Neck Surgery, Weill Cornell Medical College, 1305 York Ave, Fifth Floor, New York, NY 10021 (kfl9002 @nyp.org).
2. Qayyum S, Meacham R, Sebelik M, Zafar N. Sialolipoma of the parotid gland: case report with literature review comparing major and minor salivary gland sialolipomas. J Oral Maxillofac Pathol. 2013;17(1):95-97. 3. Bansal B, Ramavat AS, Gupta S, et al. Congenital sialolipoma of parotid gland: a report of rare and recently described entity with review of literature. Pediatr Dev Pathol. 2007;10(3):244-246. 4. Hornigold R, Morgan PR, Pearce A, Gleeson MJ. Congenital sialolipoma of the parotid gland first reported case and review of the literature. Int J Pediatr Otorhinolaryngol. 2005;69(3):429-434.
Section Editor: Rebecca S. Cornelius, MD. Published Online: June 11, 2015. doi:10.1001/jamaoto.2015.0963. Conflict of Interest Disclosures: None reported. Previous Presentation This case was presented at the 2014 SENTAC Annual Meeting; December 4-7, 2014; St Louis, Missouri. REFERENCES 1. Nagao T, Sugano I, Ishida Y, et al. Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma. Histopathology. 2001;38(1):30-36.
766
erogeneously on T1 postcontrast with fat suppression (Figure, B), and suppressed relatively uniformly on STIR sequences (Figure, C). These findings indicate a well-encapsulated lipomatous lesion with admixed heterogeneous tissue consistent with sialolipoma. On computed tomographic examination, sialolipomas and other lipomatous lesions appear with low density consistent with adipose tissue.1,9 However, definitive diagnosis of sialolipoma requires histopathologic examination to differentiate a benign lipomatous tumor from a more aggressive variant.4 The differential diagnosis for a lipomatous mass in the parotid gland includes lipoma, lipomatosis, lipoadenoma, fibrolipoma, spindle cell lipoma, and lipoblastoma. Lipomas do not have admixed glandular tissue and are therefore homogeneously hyperintense on T1- and T2-weighted images.8 Lipomatosis is nontumoral expansion of adipose tissue in the parotid gland causing diffuse enlargement without a well-defined capsule. It occurs gradually with advancing age and can also occur with systemic conditions such as diabetes mellitus or human immunodeficiency virus.1,10 Lipoadenomas, as the name suggests, are neoplastic growths of glandular tissue with adipose tissue as its secondary component.8,10 In contrast, sialolipomas are benign growths of mature adipose tissue interspersed with normal glandular tissue. Fibrolipomas are nonencapsulated, benign lipomatous tumors containing dense connective tissue.5 Finally, spindle cell lipomas and lipoblastomas are rare tumors containing mature adipose tissue that may be encapsulated. Spindle cell lipomas are distinguished by bland spindle cells, and lipoblastomas contain immature lipoblasts in addition to mature fat cells.5 Treatment of sialolipomas in both major and minor salivary glands is primary surgical resection. Of the 14 reported cases of parotid gland sialolipoma, the deep lobe of the parotid gland was involved in 2 cases. In all reported cases, the mass was successfully excised without injury to the facial nerve and without evidence of recurrence.1,7
5. Jang Y-W, Kim S-G, Pai H, Park J-W, Lee Y-C, Rotaru H. Sialolipoma: case report and review of 27 cases. Oral Maxillofac Surg. 2009;13(2):109-113.
7. Khazaeni K, Jafarian AH, Khajehahmadi S, Rahpeyma A, Asadi L. Sialolipoma of salivary glands: two case reports and review of the literature. Dent Res J (Isfahan). 2013;10(1):93-97. 8. Agaimy A. Fat-containing salivary gland tumors: a review. Head Neck Pathol. 2013;7(suppl 1):S90-S96. 9. Michaelidis IG-A, Stefanopoulos PK, Sambaziotis D, Zahos MA, Papadimitriou GA. Sialolipoma of the parotid gland. J Craniomaxillofac Surg. 2006;34(1): 43-46. 10. Kadivar M, Shahzadi SZ, Javadi M. Sialolipoma of the parotid gland with diffuse sebaceous differentiation in a female child. Pediatr Dev Pathol. 2007;10(2):138-141.
6. Kidambi T, Been MJ, Maddalozzo J. Congenital sialolipoma of the parotid gland: presentation, diagnosis, and management. Am J Otolaryngol. 2012;33(2):279-281.
JAMA Otolaryngology–Head & Neck Surgery August 2015 Volume 141, Number 8 (Reprinted)
Copyright 2015 American Medical Association. All rights reserved.
Downloaded From: http://archotol.jamanetwork.com/ by a Rutgers University Libraries User on 03/08/2016
jamaotolaryngology.com
Clinical Challenge | RADIOLOGY
Left Parotid Gland Swelling in an Infant Kenny F. Lin, MD; Marc A. Cohen, MD; Vikash K. Modi, MD
A T1-Weighted sequence
B
C
D Left preauricular in situ during surgical excision
Short T1 inversion recovery sequence
T1-Weighted sequence postcontrast with fat suppression
Figure. Magnetic resonance images of a patient with a left preauricular mass of the superficial parotid lobe.
An infant girl presented to the pediatric otolaryngology clinic with a 2-month history of an enlarging left preauricular mass. The parents first noticed a pea-sized nodule in front of her left ear that was now 3 cm, soft, mobile, and nontender, without overlying skin changes or facial nerve impairment. The infant was otherwise well without fevers, feeding well, and growing appropriQuiz at ately. Her mother had a full-term vaginal delivery withjamaotolaryngology.com out complications and a medical history that was notable only for gastroesophageal reflux disease treated with ranitidine. Ultrasonography showed a 2.2 × 3.0-cm solid nodule. The patient was then referred for magnetic resonance imaging (MRI) with contrast, which showed a 2.9 × 1.6 × 2.3-cm mass with a welldefined capsule arising from within the superficial left parotid gland. The mass was largely of fat signal intensity on both T1-weighted (Figure, A) and T2-weighted sequences with heterogeneous soft-tissue enhancement on T1 post-contrast (Figure, B). The mass also suppressed relatively uniformly on short T1 inversion recovery (STIR) sequence (Figure, C). The Figure, D, shows the mass in situ during surgical excision with facial nerve monitoring.
jamaotolaryngology.com
WHAT IS YOUR DIAGNOSIS?
A. Parotitis B. Lipoma C. Sialolipoma D. Hemangioma
(Reprinted) JAMA Otolaryngology–Head & Neck Surgery August 2015 Volume 141, Number 8
Copyright 2015 American Medical Association. All rights reserved.
Downloaded From: http://archotol.jamanetwork.com/ by a Rutgers University Libraries User on 03/08/2016
765
Clinical Review & Education Clinical Challenge
Diagnosis C. Sialolipoma
Discussion Cytologic findings from fine-needle aspiration suggested a lipomatous lesion without definitive lipoblasts. The case was discussed during a multidisciplinary head and neck tumor board meeting. The team decided to proceed with surgical resection with facial nerve monitoring. A well-circumscribed mass embedded superficially in the parotid tissue and lateral to the facial nerve was excised without complication. Histopathologic examination showed a tan, lobulated soft mass most consistent with sialolipoma. At follow-up, facial nerve function was preserved without recurrence of the mass. Sialolipomas are benign lipomatous tumors arising from salivary gland tissue and have only recently been recognized as a distinct entity. Nagao et al 1 described sialolipomas as wellencapsulated tumors comprised primarily of mature adipose tissue admixed with normal salivary glandular tissue. They arise from both major and minor salivary glands and are theorized to be lipomas with secondary entrapment of salivary gland elements.1 A literature review found 36 total cases with 14 cases involving the parotid gland.2-8 Lipomatous lesions are found in 0.5% to 1% of all parotid gland tumors, and most occur in males during late adulthood (mean age, 55 years).1,8 Sialolipomas in the parotid gland, however, are a subset with equal incidence between sexes. The reported age range is 6 weeks to 77 years, with 90% of cases occurring in adulthood.2-7 The most common cause of parotid gland swelling in childhood is parotitis, and the most common congenital tumor is hemangioma.4 After ultrasonography demonstrated a solid nodule in the left parotid gland, an MRI scan was obtained. Adipose tissue is bright on both T1- and T2-weighted sequences, does not restrict diffusion on diffusion weighted imaging (appearing hypointense), and is dark on fatsuppressed STIR sequences.1 In this case, the mass was largely of fat signal intensity on both T1 (Figure, A) and T2 images, enhanced hetARTICLE INFORMATION Author Affiliations: Department of Otorhinolaryngology–Head and Neck Surgery, Weill Cornell Medical College, New York, New York. Corresponding Author: Kenny F. Lin, MD, Department of Otorhinolaryngology–Head and Neck Surgery, Weill Cornell Medical College, 1305 York Ave, Fifth Floor, New York, NY 10021 (kfl9002 @nyp.org).
2. Qayyum S, Meacham R, Sebelik M, Zafar N. Sialolipoma of the parotid gland: case report with literature review comparing major and minor salivary gland sialolipomas. J Oral Maxillofac Pathol. 2013;17(1):95-97. 3. Bansal B, Ramavat AS, Gupta S, et al. Congenital sialolipoma of parotid gland: a report of rare and recently described entity with review of literature. Pediatr Dev Pathol. 2007;10(3):244-246. 4. Hornigold R, Morgan PR, Pearce A, Gleeson MJ. Congenital sialolipoma of the parotid gland first reported case and review of the literature. Int J Pediatr Otorhinolaryngol. 2005;69(3):429-434.
Section Editor: Rebecca S. Cornelius, MD. Published Online: June 11, 2015. doi:10.1001/jamaoto.2015.0963. Conflict of Interest Disclosures: None reported. Previous Presentation This case was presented at the 2014 SENTAC Annual Meeting; December 4-7, 2014; St Louis, Missouri. REFERENCES 1. Nagao T, Sugano I, Ishida Y, et al. Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma. Histopathology. 2001;38(1):30-36.
766
erogeneously on T1 postcontrast with fat suppression (Figure, B), and suppressed relatively uniformly on STIR sequences (Figure, C). These findings indicate a well-encapsulated lipomatous lesion with admixed heterogeneous tissue consistent with sialolipoma. On computed tomographic examination, sialolipomas and other lipomatous lesions appear with low density consistent with adipose tissue.1,9 However, definitive diagnosis of sialolipoma requires histopathologic examination to differentiate a benign lipomatous tumor from a more aggressive variant.4 The differential diagnosis for a lipomatous mass in the parotid gland includes lipoma, lipomatosis, lipoadenoma, fibrolipoma, spindle cell lipoma, and lipoblastoma. Lipomas do not have admixed glandular tissue and are therefore homogeneously hyperintense on T1- and T2-weighted images.8 Lipomatosis is nontumoral expansion of adipose tissue in the parotid gland causing diffuse enlargement without a well-defined capsule. It occurs gradually with advancing age and can also occur with systemic conditions such as diabetes mellitus or human immunodeficiency virus.1,10 Lipoadenomas, as the name suggests, are neoplastic growths of glandular tissue with adipose tissue as its secondary component.8,10 In contrast, sialolipomas are benign growths of mature adipose tissue interspersed with normal glandular tissue. Fibrolipomas are nonencapsulated, benign lipomatous tumors containing dense connective tissue.5 Finally, spindle cell lipomas and lipoblastomas are rare tumors containing mature adipose tissue that may be encapsulated. Spindle cell lipomas are distinguished by bland spindle cells, and lipoblastomas contain immature lipoblasts in addition to mature fat cells.5 Treatment of sialolipomas in both major and minor salivary glands is primary surgical resection. Of the 14 reported cases of parotid gland sialolipoma, the deep lobe of the parotid gland was involved in 2 cases. In all reported cases, the mass was successfully excised without injury to the facial nerve and without evidence of recurrence.1,7
5. Jang Y-W, Kim S-G, Pai H, Park J-W, Lee Y-C, Rotaru H. Sialolipoma: case report and review of 27 cases. Oral Maxillofac Surg. 2009;13(2):109-113.
7. Khazaeni K, Jafarian AH, Khajehahmadi S, Rahpeyma A, Asadi L. Sialolipoma of salivary glands: two case reports and review of the literature. Dent Res J (Isfahan). 2013;10(1):93-97. 8. Agaimy A. Fat-containing salivary gland tumors: a review. Head Neck Pathol. 2013;7(suppl 1):S90-S96. 9. Michaelidis IG-A, Stefanopoulos PK, Sambaziotis D, Zahos MA, Papadimitriou GA. Sialolipoma of the parotid gland. J Craniomaxillofac Surg. 2006;34(1): 43-46. 10. Kadivar M, Shahzadi SZ, Javadi M. Sialolipoma of the parotid gland with diffuse sebaceous differentiation in a female child. Pediatr Dev Pathol. 2007;10(2):138-141.
6. Kidambi T, Been MJ, Maddalozzo J. Congenital sialolipoma of the parotid gland: presentation, diagnosis, and management. Am J Otolaryngol. 2012;33(2):279-281.
JAMA Otolaryngology–Head & Neck Surgery August 2015 Volume 141, Number 8 (Reprinted)
Copyright 2015 American Medical Association. All rights reserved.
Downloaded From: http://archotol.jamanetwork.com/ by a Rutgers University Libraries User on 03/08/2016
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