Reply to the comments of Preuss and Wittekindt on our article: “Management and prognostic factors of recurrent pleomorphic adenoma of the parotid gland: personal experience and review of the literature”

Abstract

Sir, First of all, we would like to thank Drs. Preuss and Wittekindt for their comments [1] on our paper: “Management and prognostic factors of recurrent pleomorphic adenoma (RPA) of the parotid gland: personal experience and review of the literature” [2]. Of course, we agree with our colleagues on the need for surgical extirpation of RPA of the parotid gland. However, as to the kind of surgery we performed, we do not consider “exceptionally radical parotidectomy” to be an accurate characterization of the surgical procedures that we applied. As is known from collective experience, RPA is uninodular in a minority of patients and may develop following incomplete excision of the tumor at the initial surgery. In such cases, surgical removal of RPA must be proportionate to the volume and site (superWcial or deep lobe), ranging from limited removal to total parotidectomy. The probability of further relapses is very low. However, in the majority of RPAs the recurrence is multinodular and widely disseminated in the parotid gland and space (sometimes also in the parapharyngeal space), with tumor nodules in the overlying skin (especially the scar), in subcutaneous tissue, in muscle, and in sheets of the facial nerve trunk and branches. Indeed, although hypothetical and diYcult to test, the distribution of the recurring tumor seems to reXect the extent of growth of neoplastic cells in the parotid space and its walls at the time of the Wrst surgical excision. In such cases of widespread tumor dissemination there are two choices for surgical removal: total parotidectomy or, better, clearance of the parotid space, of course with preservation of the facial nerve tree. Even so, in multinodular and extended recurrences, one can be almost certain, on the grounds of literature and personal experience, that microscopic remnants of the tumor will often remain at the end of the procedure, even in an apparently clean surgical Weld, resulting in further relapses. The rationale for postoperative radiotherapy, when it can be applied without undue risk to the patient (contraindicated mainly in young patients), is to try to slow (or halt) the growth of those microscopic tumor remnants. We agree that the literature results are not unanimous on the advantages of postoperative radiotherapy [2–8]. On the other hand, there are also reports of adverse eVects of radiotherapy in RPA [6]. As to management of the facial nerve, 4 of the 26 patients who received initial surgery elsewhere presented with deWnitive hemifacial paralysis prior to our RPA treatment. In one of these latter patients the facial trunk was found to be encased by the recurring tumor and was excised with no attempt to restore nerve continuity (clearly, such an attempt would have been futile). Out of the seven patients who were initially treated at our department, none had facial paralysis. In the whole group, i.e., 33 patients, we found facial nerve branches enveloped by the tumor in 9: the marginal mandibular nerve in 7, a midface branch to the orbicular oris muscle in 1 and a branch to the frontalis muscle in 1. In these patients a piece of the involved nerve branch was excised, with no attempt to reconstruct nerve continuity, Wrst because of the usually poor functional results, at least in our hands, after grafting the marginal mandibular or the temporal nerve branch, and second because of the existing “redundancy” of the motor nerve supply to the muscles of L. O. Redaelli de Zinis (&) · M. Piccioni · A. R. Antonelli · P. Nicolai Department of Otorhinolaryngology-Head Neck Surgery, University of Brescia, Piazzale Spedali Civili, 1, 25123 Brescia, Italy e-mail: redaelli@med.unibs.it