Masses associated with erythema and local calor suggest an inflammatory or infectious etiology. Suspicious skin lesions or a history of skin lesion excision may suggest metastatic spread to the parotid or submandibular lymph nodes. A thorough search of the head and neck is required to rule out other primary lesions or metastatic adenopathy. Particular attention should be given to the size of the mass, differentiation of single versus multiple masses, the presence or absence of fixation to deeper structures, and neurologic examination. The use of ancillary diagnostic procedures is guided by the history and physical examination.
Plain films are occasionally useful for ruling out ductal calculi in the submandibular ducts.
Ultrasonography also demonstrates ductal calculi, and is particularly suited to distinguishing solid lesions from cystic lesions and single lesions from multiple ones. CT and MR images give more information about primary and metastatic extension to surrounding structures. CT images are useful for evaluating bone erosion, but may be severely degraded by dental restoration artifacts. MR images provide 'de superior soft tissue detail, but may not demonstrate bone involvement. Both CT and MR demonstrate cervical lymphadenopathy.