Differential diagnosis BMT-Whartin Parotid Mass Differential diagnosis BMT-Whartin

Annual Incidence salivary gland tumoUrs 0,4-13,5 cases per 100.000 population Malignant: 0,4-2,6 cases per 100.000 population 64-80% parotid gland Benign: 54-79% Malignant parotid: 15-32% Pleomorphic adenoma 50% of all benign Whartin tumour second Mucoepidermöid carcinoma most common malignant

Pleomorphic adenoma(BMT) WHARTIN TUMOUR all ages (mean 46) slight female predominance no site predominance solitary mass (<1% multifocal) dystrofic calcification may be present small BMT (<2 cm): sharply marginated ovoid with uniform enhancement large BMT(>2 cm): lobulated with heterogeneous enhancement “peer shaped” when arising in deep lobe all ages (mean 62), rare before 40 male predominance strong link with smoking “Adult male smoker” lower pole predominance 20% multicentric (syn-of metachronous) does not calcify parenchymal heterogeneity (cystic component 30%)

CT BMT Whartin

MRI BMT Whartin T1 T1 ce T2 T1 ce T2

Deep lobe BMT MRI T1 T2 T1 ce Large symptomatic mass arising from deep lobe of parotid: almost always BMT!!

When to suspect malignacy? Gradual onset facial nerve paresis Heterogeneous inflitrating mass with poorly defined margins Perineural tumor spread (adenocystic carcinoma) Adjacent invaded lymph node (muco-epidermoïd carcinoma)