Recurrent Benign Salivary Gland Neoplasms

Abstract

The most important causes of recurrence of benign pleomorphic adenoma are enucleation with intraoperative spillage and incomplete tumor excision in association with characteristic histologic findings for the lesion (incomplete pseudocapsule and the presence of pseudopodia). Most recurrent pleomorphic adenomas (RPAs) are multinodular. MRI is the imaging method of choice for their assessment. Nerve integrity monitoring may reduce morbidity of RPA surgery. Although treatment of RPA must be individualized, total parotidectomy is generally recommended given the multicentricity of the lesions. However, surgery alone may be inadequate for controlling RPA over the long term. There is growing evidence from retrospective series that postoperative radiotherapy results in significantly better local control. A high percentage of RPAs are incurable. All patients should therefore be informed about the possibility of needing multiple treatment procedures, with possible impairment of facial nerve function, and radiation therapy for RPA. Reappearance of Warthin tumor is a metachronous occurrence of a new focus or residual incomplete excision of all primary multicentric foci of Warthin tumor. Selected cases can be observed. Conservative surgical management can include partial superficial parotidectomy or extracapsular dissection. Not uncommonly, other major and minor salivary gland neoplasms, including myoepithelioma, basal cell adenoma, oncocytoma, canalicular adenoma, cystadenoma, and ductal papilloma, follow an indolent course after surgical resection, with rare cases of recurrence.

Current thinking about the management of recurrent pleomorphic adenoma of the parotid: a structured review

“…A superficial or a total parotidectomy are the operations of choice in RPA of the parotid given the multicentricity of the lesions and the risk of further recurrences 12,35 . In selective cases with small volume recurrent disease an extracapsular dissection may be employed.…”

“…There is evidence from retrospective series that postoperative radiation therapy improves local control 15 . Clear margins are essential but cannot guarantee a cure in RPA 12,25 . There is evidence now that PAs slowly gain malignant characteristics after repeated recurrences 21 .…”

Facial nerve abnormality on parotidectomy for Warthin tumor in a case of aural atresia

“…[10] Superficial parotidectomy with tumor-free margins is generally sufficient for treatment, but inadequate surgical resection leads to recurrence. [11,12] Since the full extent of the facial nerve cannot be estimated before surgery, meticulous step-by-step dissection is important when separating the tumor from each branch of the facial nerve. The location and size of tumor determine the level of difficulty while handling the facial nerve.…”

AHNS series: Do you know your guidelines? Diagnosis and management of salivary gland tumors

“…While this still represents a benign process even in the recurrent setting, the possibility of malignant conversion to carcinoma ex‐pleomorphic adenoma still exists, and such patients are considered for additional treatment including revision surgery. Due to elevated risk for facial nerve paresis in the revision or multiply recurrent setting, patients may be considered for RT, with some series showing promising results in terms of improved locoregional control …”

“…Due to elevated risk for facial nerve paresis in the revision or multiply recurrent setting, patients may be considered for RT, with some series showing promising results in terms of improved locoregional control. [76][77][78][79][80] In selected patients with salivary malignancies undergoing surgical resection of their primary tumor, with or without neck dissection, adjuvant radiation is also recommended. Due to its high propensity for local recurrence as well as perineural invasion, all patients with ACC are recommended to have postoperative radiation.…”