General Data
� Age : 39 y/o
� Gender : female
� Marriage : 已婚
Chief Complaint
� A palpable mass over right cheek which was found for 1 year
Present Illness
� A palpable mass about 1.5 x 1.5 cm was found in 1 year ago.
� The mass become bigger recently
� Intermittent neck pain and stiffness
� No pain, no tenderness, no wound, no numbness
Past history
� T-colon cancer, s/p segmental resection at 新光, chemotherapy in 北醫 about 4 years ago
� DM (-)
� Hypertension (-)
� Allergy (-)
Lab data
� WBC : 6.89 10^3/u
� RBC : 4.47 10^6/uL
� Na : 133 mEq/L
� K : 3.8 mEq/L
� There is an ill-defined round mass, about 2.0x1.9x1.5 cm in size, with inhomogeneous parenchymal enhancement in the anterior superficial lobe of right parotid gland.
D/D from Image
� Plemorphic adenoma
� Warthin’s tumor
� Mucoepidermoid carcinoma
� Adenoid cystic carcinoma
� Squamous cell carcinoma
� Metastasis
D/D from parotid gland
� LocationThe lobe of Parotid gland
Parapharyngeal area, tonsillar area, Cervical lymph node
� SymptomsFacial nerve paralysis
� AgeBenign tumor → 40 ~ 60 y/o
Malignancy → elderly
� Gender大部分均是女性較多
Warthin’s tumor →男性較多
Diagnosis approach
� CT
� MRI
� Ultrasound
� Fine needle aspiration
� Core biopsy
Plemorphic adenoma
� Most common benign tumor of salivary gland
� Location : tail or superficial lobe
� CT : isodense to muscle and shows
moderate enhancement
� MRI : the mass is T1 hypointense (T2
hyperintense) to surrounding fat
Warthin’s tumor
� The second most common benign tumor of parotid
� Bilateral in 10% of cases and favors the tail of the parotid gland
� MRI : T1 hypointense to the surrounding
parotid fat
Mucoepidermoid carcinoma
� Most common malignant tumor of the parotid gland.
� CT : the mass is isodense to muscle
� MRI : T1 hypointense to surrounding
parotid fat but variable on T2
Adenoid cystic carcinoma
� The second most common malignant tumor of parotid
� CT : isodense to muscle
� MRI : T1 hypointense to surrounding
parotid fat but variable on T2
Final diagnosis
� Surgery :
1. excision of parotid gland tumor
2. superficial parotidectomy
� Pathology :
Epithelial-myoepithelial carcinoma
Discussion
Parotid gland tumor
� The most common location of salivary gland tumors
� Tumor usually present with a solitary, discrete, slowly growing, asymptomatic mass.
The rule of 80
� 80% of parotid tumors are benign
� 80% of parotid tumors are pleomorphicadenomas
� 80% of parotid pleomorphic adenomas occur in the superficial lobe
� 80% of untreated pleomorphic adenomas remain benign
Diagnostic evaluation
Fine needle aspiration
� Identify the causes of parotid enlargement
� Determine whether it is primary to the salivary gland or metastatic from another site
� The accuracy of FNA depends upon operator experience
Core needle biopsy
� Ultrasound-guided core needle biopsy of parotid masses is highly accurate (97~100%)
� More accurate typing and grading of malignant lesions
Image study
� Ultrasond
Location, the nature of the mass
� CT & MRI :
Provide important diagnostic information about overall dimension, adjacent tissue infiltration, and vascular invasion
It might be malignancy…
� Tumors of the deep parotid lobe or those which
extend into the parapharyngeal space
� Recurrent tumors
� Direct facial nerve invasion, skin involvement, or
extension into bone
� Locally extensive lesions
� The presence of pathologic cervical
lymphadenopathy
Staging system
Tumor invades skull base, and/or pterygoid plates and/or encases carotid artery
T4b
Tumor invades skin, mandible, ear canal, and/or facial nerve.T4
a
Tumor more than 4 cm and/or extraparenchymal extensionT3
Tumor more than 2 cm but not more than 4 cm in greatest dimension without extraparenchymal extension
T2
Tumor 2 cm or less in greatest dimension without extraparenchymal extension
T1
No evidence of primary tumorT0
Primary tumor cannot be assessedTX
Tumor size
Staging system
Metastasis in a lymph node more than 6 cm in greatest dimensionN3
Metastasis in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension
N2c
Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension
N2b
Metastasis in a single ipsilateral lymph node more than 3 cm but not more than 6 cm in greatest dimension
N2a
Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension, or in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension, or in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension
N2
Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimensionN1
No regional lymph node metastasisN0
Regional lymph nodes cannot be assessedNX
Nodal status
Staging system
M1Any NAny TStage IVC
M0N2-3Any T
M0Any NT4bStage IVB
M0N2T1-4a
M0N0-1T4aStage IVA
M0N1T1-3
M0N0T3Stage III
M0N0T2Stage II
M0N0T1Stage I
Tumor stage grouping
Treatment---T1/T2
� Superficial or total parotidectomy with conservation of the facial nerve
� low-grade T1 and T2 primaries can be adequately treated by surgery alone
� RT is recommended for …..
� Deep lobe parotid tumors
� Close or positive histologic surgical margins
� Undifferentiated or high-grade histology
� Recurrent malignancy
� Bone or connective tissue involvement
� Metastatic regional cervical lymph nodes
� Perineural involvement
� Intraoperative tumor spillage or capsular rupture
Treatment---T3/T4
� Superficial or total parotidectomy +
postoperative radiotherapy
� Five-year survival rates for patients treated with and without RT were :
51% : 10%
Prognosis
� 10-year survival rates :
14%Stage Ⅳ
43%Stage Ⅲ
69%Stage Ⅱ
85%Stage Ⅰ
Epithelial-myoepithelial carcinoma
( EMEC )
� A rare tumor accounting for slightly fewer than 1% of salivary gland neoplasms.
� Most often in elderly patients
� More prevalent in women
� The slow-growing mass is well defined, bulky lobulated fashion
CT & MRI
� CT : isodense to muscle
� MRI : hypointense on T1
� CT and MRI appearances of EMEC are nonspecific, and that EMEC cannot be differentiated from more common parotid neoplasms on the basis of its imaging characteristics.
Pathology
� The tumor has a distinctive histopathologicpattern with epithelial tubules or ductulessurrounded by neoplastic myoepithelialcells
Treatment
� Wide surgical resection, including adjacent lymph nodes
� Immediate postoperative radiotherapy
� Regular follow up
Prognosis
� There is a high reported rate of local recurrence, approaching 50%
� Resection of recurrences usually results in a good prognosis, with less than 10% of patients dying as a result of this tumor
Reference
� Uptodate : salivary gland tumor
� Robbins
�電腦斷層攝影入門
� Journal of clinical pathology :
Epithelial-myoepithelial carcinoma of salivary glands
� American Society of Neuroradiology
Epithelial-Myoepithelial Carcinoma of the Parotid Gland
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