Pleomorphic adenoma is the most common benign tumor of the salivary glands, accounting for about 60% of all salivary gland tumors. Patients with pleomorphic adenoma usually present with a painless mass of the salivary glands, and the condition is rarely associated with a painful mass.
Pleomorphic adenoma presents with a variety of histological features within the tumor, with myxoma-like tissue and cartilage components admixed with epithelial cell proliferation, which may be accompanied by cystic degeneration. Necrosis of these salivary gland tumors following fine-needle aspiration biopsy has been documented. However, spontaneous necrosis of pleomorphic adenomas is extremely rare. We report a case of a 32-year-old woman who presented with a rapidly growing painful swelling under the mandible. Ultrasonography revealed a tumor in the right submandibular gland. Fine-needle biopsy of the right submandibular gland led to suspicion of a malignant tumor. We performed surgical resection of the submandibular gland. The histopathological diagnosis was pleomorphic adenoma with extensive internal necrosis.
