Xanthogranulomatous Sialadenitis, a benign mimic of malignancy

Abstract

A 60-year-old woman was referred to the Plastic Surgery outpatients with a %-week history of a lump in the right side of her neck. This was uncomfortable, but there were no other specific symptoms at presentation. She was taking carbimazole for thyrotoxicosis and digoxin for atria1 fibrillation. In 1967, she had undergone surgery to remove a pleomorphic adenoma from an accessory lobe of her right parotid gland. She did not have sialography or any further treatment for this condition. Physical examination confirmed a hard mass in the right side of the neck below and behind the angle of the mandible, fixed to the sternocleidomastoid. There was no lymphadenopathy. The clinical diagnosis was of a neoplasm arising in the lower pole of the parotid gland. Fine needle aspiration showed necrotic tissue with inflammatory cells, but no evidence of malignancy. Magnetic Resonance Imaging showed fatty change in the upper pole of the parotid. An ill-defined, lobulated mass involved the inferior part of the superficial and deep lobes, with characteristics typical of an infiltrating malignancy (Fig. lA, B). Ultrasound with Doppler examination confirmed these appearances, demonstrating vascular changes consistent with a neoplastic circulation. At surgery, the mass seemed to invade the sternocleidomastoid. The patient, therefore, underwent a total parotidectomy, sparing the facial nerve, and a radical neck dissection. She has since made an uneventful recovery with no facial palsy. The resected specimen is unique. On sectioning, the mass was centrally yellow and friable; grey and more fibrous peripherally. It had spread into the adjacent muscle and two discrete jugular lymph nodes had further separate deposits. Histology showed a highly cellular granulomatous inflammatory process with numerous foamy and fat-