[The recurrent multifocal pleomorphic adenoma].

Abstract

Pleomorphic adenoma (P.A.), the most common tumor of the salivary gland, demonstrates a peculiar clinicopathological behaviour for numerous reasons: the high recurrence rate following primary surgery (up to 50%), the appearance of malignancy (2-9%), the reported number of distant metastases histologically identical to the primary P.A. From among 71 cases of benign parotid tumors treated from Nov. 89 to Nov. 92 in the ENT Department of "Regina Elena", the National Cancer Institute in Rome, six particular cases showed multiple force of P.A. recurring after primary surgery performed from 3 to 32 years previously and are object of discussion in this study. All of these six cases had multiple recurrences, usually manifest as nodular clusters in the parotid area, while in three cases appeared as well a recurrence in the soft tissue of the neck, far removed from the parotid space, with no involvement of neck nodes as was revealed through histological examination following neck dissection. A hypothetical mechanism of diffusion is discussed. The Authors agree with the opinion which holds the surgeon's inability to successfully eradicate primary tumors responsible for the high frequency of recurrences. The surgical technique of "enucleation" is, in fact, inadequate in P.A. excision owing the high risk of mishandling or rupturing the tumor capsule with a consequent seeding of the tumor onto the surgical bed. Lateral lobectomy, with identification of the facial nerve, or total conservative parotidectomy (for deep lobe adenoma) are correct techniques in treating primary P.A.. The Authors also discuss management of recurrent P.A. in relation to facial nerve involvement. Preservation of the seventh nerve with eventual post-operative radiation should be considered an alternative to nerve sacrifice in selected cases of recurrent pleomorphic adenoma.