NECROSIS IN BENIGN SALIVARY-GLAND NEOPLASMS - NOT NECESSARILY A SIGN OF MALIGNANT TRANSFORMATION

Necrosis that occurs in a salivary gland neoplasm is usually considere d to be an ominous sign, suggesting malignant transformation, particul arly in lesions that have had no prior manipulation such as fine-needl e aspiration. We describe five pleomorphic adenomas and two canalicula r adenomas of salivary gland origin that exhibited necrosis, yet were otherwise benign. All lesions displayed a distinctive histopathologic pattern characterized by a narrow rim of viable tumor tissue at the pe riphery of the neoplasm combined with a diffuse central region that de monstrated apparent ischemic necrosis. No invasion of adjacent normal tissue was identified, and no recurrence or metastasis has been seen w ith these lesions. Caution should be exercised in the evaluation of sa livary gland neoplasms with central necrosis to avoid misdiagnosis of all such lesion as malignant.