Parotid Gland Non-Sebaceous Lymphadenoma: A Case Report

We here report a rare salivary gland tumor, a non-sebaceous lymphadenoma (NSLA), in the parotid gland with positive technetium-99m (99mTc) pertechnetate scintigraphy and cervical masses that was difficult to distinguish from malignant lymphoma preoperatively. A 65-year-old Japanese woman presented to our institution with a painless left parotid mass that had been gradually enlarging for three months. Computed tomography and magnetic resonance imaging showed a solid mass (30 mm) in the tail of the left parotid gland with three swellings (each 10 mm) on the periphery of the parotid gland. A low grade malignant lymphoma was diagnosed by fine needle aspiration cytology. Gallium-67 scintigraphy showed mild positivity. On 99mTc pertechnetate scintigraphy, the mild accumulation remained after oral stimulation with a mixture of ascorbic acid and calcium pantothenate. The patient underwent superficial parotidectomy with removal of the cervical masses. Our findings in this patient suggest that 99mTc positivity may constitute a clue to the preoperative diagnosis of NSLA that has pathologically overlapping sites with Warthin tumor.