Bilateral parotid neoplasms

We are reporting what we believe to be the second case of bilateral parotid neoplasm occuring synchronously with differing histologies. We believe that this neoplasm may represent a specific propensity of parotid tissue in a given individual to develop neoplasia in a multipotential glandular organ subject to many neoplastic diseases. There also exists the possibility that this condition may represent an immune deficiency specific to the parotid gland. The case reports that have been reviewed demonstrate that a secondary neoplasm may arise from benign mixed tumors. We question whether this is an example of monistic origin of acinic cell tumor from a mixed-cell tumor or, perhaps, dualistic expression for this salivary gland to develop a multiplicity of anaplastic and metaplastic growth variants. In approaching a case with bilateral parotid involvement, the physician must be aware of the rare possibility that benign and malignant tumors may coexist. He must be prepared to proceed with more radical extirpation than simple superficial parotidectomy.