Presentation
Painless swelling of the left parotid gland.
Patient Data
The MRI sequences demonstrate a well-defined lobulated ovoid mass within the superficial lobe of the left parotid gland. It displays a low signal on T1WI, slightly high signal on T2WI with a peripheral hypointense capsule. On DWI it shows a high signal with low ADC (restricted diffusion).
The ADC within the mass was 0.4 x normal (0.3×10-3 mm2/sec in this case). The TIC (time signal intensity curve) shows an early enhancement and low wash-out within the tumor giving the appearance of a TIC type C according to Yabuuchi et al classification.
Small left upper cervical lymphadenopathy is noted.
The right parotid gland appears normal.
Case Discussion
MR features are most consistent of malignant parotid gland tumor
An FNA was performed and showed characteristic features of non-Hodgkin lymphoma (non-MALT subtype).
Primary non-Hodgkin lymphoma (NHL) of the salivary glands is considered as an uncommon tumor, comprising 2% of all salivary gland neoplasms 1. There are two subtypes mucosa-associated lymphoid tissue (MALT) and non-MALT lymphomas 1. MALT subtype is more common. Both subtypes vary in their prognosis and treatment1.
Additional contributors: R. Bouguelaa, MD, ZE. Boudiaf, MD