Imaging Technique. Ultrasound Imaging of the Salivary Glands. Parotid Gland. The Major Salivary Glands. Parotid Gland: Stenson s Duct.

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1 Ultrasound Imaging of the Salivary Glands Edward G. Grant MD Professor & Chairman, Dept of Radiology USC Keck School of Medicine Imaging Technique Linear array transducer Superficial location Highest MHz possible Color/power Doppler Mass evaluation, inflammatory processes Bilateral examination Lower neck for nodes, thyroid primary etc CT/MR for deep parotid lobe The Major Salivary Glands Parotid Gland Bialek EJ. Radiographics 2006; 26: 745 Located in retromandibular fossa Anterior to ear and sternocleidomastoid muscle Covers posterior mandible/masseter muscle Facial nerve divides superficial/deep lobe Not usually visible with US Adjacent to retromandibular vein/eca Homogeneously echogenic (~ fat content) Benign intraglandular nodes common Parotid Gland: Stenson s Duct Main excretory duct Crosses masseter muscle, ~ 1cm zygoma Orifice, level of second upper molar 3-5 cm length Visible - high resolution technique/dilatation Site of ectopic parotid gland/tumors Present as cheek masses 1

2 Stenson s Duct Submandibular Gland Located in posterior submandibular triangle Borders = anterior/posterior bellies of the digastric muscle & mandible. Anteriorly = connective tissue and lymph nodes (US differentiates node vs gland) Posteriorly, gland bordered by myelohyoid and hyoglossus muscles Tubular structures = Wharton s duct vs facial artery (color Doppler) Normal Submandibular Gland Facial Artery Normal Submandibular Gland: Wharton s Duct Sublingual Gland Sublingual Gland Located between muscles of the floor of the oral cavity: geniohyoid muscle, tongue, hyoglossal muscle (medially) & mylohyoid muscle, mandible laterally. Oval on trans, lenticular on long sections Wharton s duct lies on medial surface 2

3 Inflammatory Processes: Acute Acute Sialadenitis & Calculus Most common salivary gland pathology Painful, swollen, often bilateral Viral in children - Mumps, CMV Bacterial in adults -Staph aureus, oral flora US enlarged, hypoechoic, hypervascular Associated lymph adenopathy Complication = intra-glandular abscess Traxler M. Int J Oral Maxfac Surg 1992;21:360 Parotid Abcess Chronic Sialadenitis Intermittant chronicly painful swollen gland? Associated with food ingestion Unilateral or bilateral US Normal to small size Hypoechoic inhomogeneous Multiple small round lesions (previous slide) Differential = AS & CS, sarcoid, granulomatous sialadenitis, CA, Sjogren s, HIV Chronic Sialadenitis Chronic Sialadenitis Duct Ectasia 3

4 Chronic Sialadenitis: Duct Ectasia & Abscess Chronic Sialadenitis: MRI Chronic Sialadenitis Duct Ectasia vs Cystic Disease US > MR Duct Ectasia: Before and After 4

5 Sialolithiasis Stones Submandibular gland = 60-90% cases Parotid gland = 10-20% cases obstruction recurrent swelling, infection Radiographs insensitive CT may miss radiolucent stones (80%) US likely most sensitive technique Also images dilated ductal system Sjogren s Syndrome Sjogren s Syndrome Chronic lymphocytic/plasma cell infiltration destruction of salivary & lacrimal glands dry eye/mouth Females > 40 years Associated with lymphoproliferative disease US screening for lymphomatous masses FNA for lesions > 2 cm US = inhomogeneous, hypoecoic nodules Gritzmann N, et al. Eur Radiol 2003; 13: 964 Salivary Gland Neoplasms Relatively rare tumors 70-80% benign 80-90% in parotid gland (< 30% malignant) 10-12% in submandibular gland >50% malignant The smaller the gland, the more likely lesions will be malignant Present as slow growing painless mass Silvers AR. Radiol Clin North Am 1998; 36: 941 Salivary Gland Masses: Benign Lesions Pleomorphic adenoma Warthin s tumor Oncocytoma Basal cell adenoma Hemangioma (children/young adults) Lipoma Schwanoma Cysts/Nodes 5

6 Pleomorphic Adenoma Pleomorphic Adenoma Majority in parotid gland (60-90%) 4-5 th decade Female > male Usually solitary and unilateral May undergo malignant transformation Treated conservative surgery US appearance varied Cystic Pleomorphic Adenoma Warthin s Tumor Adenolymphoma, cystadenolymphoma, papillary cystadenoma lymphomatosum 5-10% of salivary neoplasms 5-6 th decade Male > female Typically singular, may be multifocal May undergo malignant transformation Surgery = simple enucleation Warthin s Tumor Parotid Oncocytoma 6

7 Hemangioma Parotid Hemangioma Typically found in children/young adults May have suggestive US appearance Internally striated Phleboliths Vascular by color/power Doppler Blood on FNA Salivary Gland Cysts Epidermal Inclusion Cyst Highly viscous material larger needle Salivary vs Perisalivary Masses Reactive Node Common, often indistinguishable clinically US highly accurate Differential: Adenopathy (intra and extra glandular) Abscess Cystic lesions: branchial cleft/thyroglossal duct US guided FNA Nodes (? lymphoma) flow cytometry 7

8 Reactive Node Branchial Cleft Cyst Always send for flow cytometry Malignant Salivary Lesions Mucoepidermoid Carcinoma Mucoepidermoid CA (variously aggressive) Adenoidcystic CA ( nerve growth pain) Squamous cell CA Acinic cell CA Primary Adenocarcinoma Metastases (from H&N primaries, elsewhere) Lymphoma (primary vs systemic) Acinic Cell Carcinoma Squamous Cell Carcinoma Often cystic, mimics abscess 8

9 Squamous Cell Carcinoma: MR Always look at nodes B-Cell Lymphoma: Submandibular Gland Fine Needle Biopsy Regardless of what they say, they basically all look alike Cannot differentiate benign from malignant lesions Cannot differentiate among benign or malignant lesions Many lesions do not require surgery Inflammatory, infectious, lymphoma, mets Accurate pre-op dx pre-op planning US-guidance Histology > cytology Disadvantages Incision G needle Seeding Bleeding Core Needle Biopsy Pratap R et al. J Laryng Oto 2009;123:449 Fine Needle Aspiration (FNA) US-guidance (linear array/high MHz) No incision No/minimal complication rate G needle Cytology must be excellent 9

10 Pleomorphic Adenoma: Parotid Study Design Retrospective analysis of all US-FNA from total FNAs 45 total patients 26 (58%) 19 (42%) y.o. (median: 57 y.o.) Clinical outcome (chart review and surgical path) Sharma G, Grant EG et al. Radiology 2011; 259:471 US-FNA Adequacy and Diagnosis Subsequent Clinical Follow-Up of 48 (92%) FNA: Diagnostic 4 of 48 (8%) FNA: Nondiagnostic 20% 22% 30% 12% 8% 8% C yst Inflam m atio n B enign neo plasm M alignant prim ary M etastasis N o ndiagno stic 45 patients undergoing FNA... Lost to f/u: 3 (7%) Operative intervention: 17 (38%) Declined surgery: 4 (9%) (comorbidities) Benign FNA US f/u Conservative management: 19 (42%) Nonoperative management after nondiagnostic FNA: 2 (4%) Conclusion Most mass like lesions in salivary glands look alike Salivary gland FNA safe, easy, well tolerated Must have excellent cytology C&S depending on symptoms Spares surgery, directs treatment/surgical planning 10