Recurrent salivary gland pleomorphic adenoma: etiology, management, and results:

Optimizing Facial Function in Patients With High-Risk Recurrent Pleomorphic Adenoma and a History of Facial Nerve Injury

BACKGROUND

Parotid pleomorphic adenoma (PA) patients present significant diagnostic and surgical challenges rendering them high risk for facial nerve injury. Recurrent PA patients often present with history of facial nerve injury or previous reanimations making salvage of the facial nerve or previous reanimations significantly more complex. The study aim is to share our experience with this high risk for facial nerve injury population and review the literature.

METHODS

Adult patients with recurrent PA and history of facial nerve injury with at least 3 months of follow-up were analyzed for demographics, facial palsy history, previous head and neck surgeries, previous facial paralysis reconstruction, preoperative imaging, surgical approach, and postoperative outcomes.

RESULTS

Four female patients were identified with an average age of 62 years. All patients underwent an initial protective dissection of the facial nerve or previous reanimation reconstruction by the facial nerve reconstructive team followed by the extirpative team. The average number of previous head and neck surgeries was 5, the number of recurrences was 2, and follow-up was 20 months. Half had prior dynamic facial reanimation. Two patients underwent complete preextirpative dissection of the facial nerve resulting in neuropraxia, which recovered completely after an average of 143 days. A third patient presented with 2 recurrences, both during and after reanimation with a dually innervated free functional muscle transfer. The reconstruction was salvaged, and motion was achieved. A fourth patient presented with benign preoperative findings, but intraoperative findings confirmed malignancy, necessitating facial nerve sacrifice, followed by immediate intratemporal grafting of the facial nerve and masseteric nerve transfer. Motion appeared 139 days postoperatively.

CONCLUSIONS

A multidisciplinary effort should be implemented in this high risk for facial nerve injury population with the primary goal of protecting the facial nerve or any previous reanimation procedures, yet with preparedness to apply any reconstructive strategy based on intraoperative findings.

Pleomorphic Adenoma of the Salivary Glands and Epithelial–Mesenchymal Transition

Pleomorphic adenoma (PA) is a localized tumor that presents pleomorphic or mixed characteristics of epithelial origin and is interwoven with mucoid tissue, myxoid tissue, and chondroid masses. The literature reported that PA most often occurs in adults aged 30–60 years and is a female predilection; the exact etiology remains unclear. Epithelial–mesenchymal transition (EMT) is the transdifferentiation of stationary epithelial cells primarily activated by a core set of transcription factors (EMT-TFs) involved in DNA repair and offers advantages under various stress conditions. Data have suggested that EMTs represent the basic principle of tissue heterogeneity in PAs, demonstrating the potential of adult epithelial cells to transdifferentiate into mesenchymal cells. It has also been reported that multiple TFs, such as TWIST and SLUG, are involved in EMT in PA and that SLUG could play an essential role in the transition from myoepithelial to mesenchymal cells. Given this background, this review aims to summarize and clarify the involvement of EMT in the development of PA, chondrocyte differentiation, and malignant transformation to contribute to the fundamental elucidation of the mechanisms underlying EMT.

Rare Case Report: Young Male Hard Palate Pleomorphic Adenoma

Salivary gland tumors are rare and accounting for only 2-3% of tumors occurring in head and neck region. Pleomorphic adenoma is a benign neoplasm which is very commonly encountered in the parotid gland and other major salivary glands. Few times they can also develop in minor salivary glands of the palate. The majority of minor salivary gland tumors are malignant in nature. This case report describes a case of a young male snake charmer develops a mixed tumor in a minor salivary gland of the hard palate.

Prognostic Value of Tumor-Infiltrating Lymphocytes in Sinonasal Mucosal Melanoma

OBJECTIVES/HYPOTHESIS

Tumor-infiltrating lymphocytes (TILs) predict better outcome in several types of cancers. However, the prognostic value of TILs in sinonasal mucosal melanoma (SNMM) is uncertain. Here, we investigated whether TILs can be used as a prognostic indicator for survival in SNMM.

STUDY DESIGN

Retrospective cohort study.

METHODS

Patient history and histologic specimens from 27 patients with primary SNMM were retrospectively analyzed. TIL grade was determined and associations between TILs and AJCC tumor stage, overall survival, and recurrence-free survival were analyzed.

RESULTS

Patients with TILs in the primary tumor classified as brisk or non-brisk survived significantly longer than patients with SNMMs lacking lymphocyte infiltrates. Brisk TILs were associated with the lower T3 stage and increased recurrence-free and 5-year survival.

CONCLUSION

Our results indicate that TIL density is a strong prognostic factor for better survival in SNMM. Prospective studies with larger case numbers are warranted to determine whether TILs should be included in future AJCC staging guidelines.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Genetic drivers of non-cutaneous melanomas: Challenges and opportunities in a heterogeneous landscape

Non-cutaneous melanomas most frequently involve the uveal tract and mucosal membranes, including the conjunctiva. In contrast to cutaneous melanoma, they often present at an advanced clinical stage, are associated with worse clinical outcomes and show poorer responses to immunotherapy. The mutational load within most non-cutaneous melanomas reflects their lower ultraviolet light (UV) exposure. The genetic drivers within non-cutaneous melanomas are heterogeneous. Within ocular melanomas, posterior uveal tract melanomas typically harbour one of two distinct, sets of driver mutations and alterations of clinical and biological significance. In contrast to posterior uveal tract melanomas, anterior uveal tract melanomas of the iris and conjunctival melanomas frequently carry both a higher mutational burden and specific mutations linked with UV exposure. The genetic drivers in iris melanomas more closely resemble those of the posterior uveal tract, whereas conjunctival melanomas harbour similar genetic driver mutations to cutaneous melanomas. Mucosal melanomas occur in sun-shielded sites including sinonasal and oral cavities, nasopharynx, oesophagus, genitalia, anus and rectum, and their mutational landscape is frequently associated with a dominant process of spontaneous deamination and infrequent presence of UV mutation signatures. Genetic drivers of mucosal melanomas are diverse and vary with anatomic location. Further understanding of the causes of already identified recurrent molecular events in non-cutaneous melanomas, identification of additional drivers in specific subtypes, integrative multi-omics analyses and analysis of the tumor immune microenvironment will expand knowledge in this field. Furthermore, such data will likely uncover new therapeutic strategies which will lead to improved clinical outcomes in non-cutaneous melanoma patients.

Surgical Management of the Palatal Pleomorphic Adenoma

INTRODUCTION

Surgical excision is the basic treatment option of the palatal pleomorphic adenoma (PA), it is generally accepted to prevent for recurrence. The purpose of this study was to determine the decision criteria for the management of the palatal PA through evaluating the postoperative results of palatal PA correlation with the clinical appearance.

MATERIALS AND METHODS

All of patients were evaluated the mucosal ulceration, palatal erosion, and size with CT images in all 18 palatal PAs. The clinical features, surgical methods, and surgical results of these 18 PAs were reviewed.

RESULTS

The most common age was 51 to 70 years. One patient was in pediatric age (14 years). Females were involved more commonly than males (F:M ratio was 5:1) Mucosa was normal in 16 patients. Ulcerations of the overlying mucosa were seen in 2 cases. On the coronal CT images, hard palate was erosion in 14 patients who had involved hard palate. The size of tumors was from 7 mm to 33 mm in CT scans. Two patients were ruptured the tumor during the operation, and 1 out of 2 patients was recurred.

CONCLUSIONS

For the definitive diagnosis is necessary to perform the preoperative core biopsy for the histopathological examination, and CT is necessary for evaluating the erosion of the hard palate and severity of the erosion. Hard palatal PA can be managed by surgical enucleation and removal of the periosteum or involved bone. Soft palatal PA can be managed by surgical enucleation without mucosal resection. Rupture of the tumor is related to the recurrence.

Traumatic Epidermoid Inclusion Cyst on Cheek Area

An epidermoid inclusion cyst is basically an epidermoid cyst resulting from the traumatic implantation of epidermal elements into the dermis with their subsequent cystic transformation. A case of an epidermal inclusion cyst of the cheek region is described in a 54-year-old man, whose feature was rather unusual, in that it presented as a fixed, indurated, inflamed, and sometimes, mimicking a parotid gland infection. The cyst was particularly persistent and recurred within a month of its medical treatment and had to be re-excised along with the adjacent parotid mass.

Carcinoma ex-pleomorphic adenoma derived from recurrent pleomorphic adenoma shows important difference by array CGH compared to recurrent pleomorphic adenoma without malignant transformation

Introduction

A key step of cancer development is the progressive accumulation of genomic changes resulting in disruption of several biological mechanisms. Carcinoma ex-pleomorphic adenoma (CXPA) is an aggressive neoplasm that arises from a pleomorphic adenoma. CXPA derived from a recurrent PA (RPA) has been rarely reported, and the genomic changes associated with these tumors have not yet been studied.

Objective

We analyzed CXPA from RPAs and RPAs without malignant transformation using array-comparative genomic hybridization (array-CGH) to identify somatic copy number alterations and affected genes.

Methods

DNA samples extracted from FFPE tumors were submitted to array-CGH investigation, and data was analyzed by Nexus Copy Number Discovery Edition v.7.

Results

No somatic copy number alterations were found in RPAs without malignant transformation. As for CXPA from RPA, although genomic profiles were unique for each case, we detected some chromosomal regions that appear to be preferentially affected by copy number alterations. The first case of CXPA-RPA (frankly invasive myoepithelial carcinoma) showed copy number alterations affecting 1p36.33p13, 5p and chromosomes 3 and 8. The second case of CXPA-RPA (frankly invasive epithelial-myoepithelial carcinoma) showed several alterations at chromosomes 3, 8, and 16, with two amplifications at 8p12p11.21 and 12q14.3q21.2. The third case of CXPA-RPA (minimally invasive epithelial-myoepithelial carcinoma) exhibited amplifications at 12q13.3q14.1, 12q14.3, and 12q15.

Conclusion

The occurrence of gains at chromosomes 3 and 8 and genomic amplifications at 8p and 12q, mainly those encompassing the HMGA2, MDM2, WIF1, WHSC1L1, LIRG3, CDK4 in CXAP from RPA can be a significant promotional factor in malignant transformation.

Recurrent salivary pleomorphic adenoma shows increased immunohistologic expression of bcl-2 oncoprotein

BACKGROUND

Internal cell biology, including apoptotic regulation, is presumed to play a key role in the development of recurrent pleomorphic adenoma (PA).

AIM

The aim of our study was to determine the relevance of B-cell lymphoma 2 (bcl-2) oncoprotein immunoexpression and distribution in primary PA, and its recurrence.

METHODS

Ten primary-non-recurrent, 14 primary-to-recur, and 28 recurrences of parotid PA patients aged 19-73 (mean 40.7±16.7) years were enrolled. The bcl-2 expression was compared between groups using a semi-quantitative histoscore, defined as the multiple of the percentage of cells by the intensity of immunostaining.

RESULTS

Widely varying bcl-2 immunoreaction was found in the epithelial areas of 91.7% of primary and 85.2% of recurrent PA. Similarly varying but much less, immunopositivity was found in the myxoid areas of 62.5% of primary and 71.4% of recurrent tumours. No obvious differences in the bcl-2 staining intensity or pattern of specific epithelial morphologic structures in either the primary-non-recurrent, primary-to-recur or recurrent tumours were found. In both the mesenchymal and epithelial areas of PA, the differences in bcl-2 immunohistoscore between the primary-non-recurrent and primary-to-recur groups were not statistically significant (P=0.62, respectively 0.51). In the mesenchymal areas, the study revealed a significantly increased histoscore in recurrent tumours compared to their corresponding primaries (P=0.01). Increased bcl-2 expression in recurrent PA suggests an exaggerated aggressiveness of that tumor.

CONCLUSION

The fact that a significant difference in the histoscore was found exclusively in the myxoid component seems to accord with the reported prevalence of the latter in recurrent and metastatic PA.

Safety of extracapsular dissection in benign superficial parotid lesions

INTRODUCTION

The current practice for removal of clinically benign superficial parotid lesions is an appropriate superficial parotidectomy with a cuff of normal parotid tissue for complete pathological clearance. This technique requires the identification of the facial nerve at the main trunk and dissection of the segment of the facial nerve deep to the lesion. The reported major complications of this procedure include temporary or permanent facial nerve weakness, Frey's syndrome and salivary leaks. In order to avoid these complications, a local extracapsular dissection technique can be utilised in the management of small inferiorly located benign lesions of the parotid gland.

METHODS

A retrospective case note review was performed for all parotidectomies between 2004 and 2009 in Addenbrooke's Hospital, Cambridge by the senior authors.

RESULTS

A total of 172 cases were identified out which 46 underwent an extracapsular dissection. The average size of these lesions was 1.9 cm (0.9-2.4 cm) with all universally located inferior or posterior to the angle of the mandible. The pathologies were 14 pleomorphic adenomas, 24 Warthin's tumours, 6 lymphangiomas and 2 simple cysts. There were no post-operative facial nerve weaknesses, Frey's syndrome or salivary leaks within the extracapsular dissection group. The median follow-up of these patients were 4.6 years (2-6 years) with 6 patients lost to follow-up. No recurrences have been noted in the cohort at follow-up.

Multinodular neck recurrence of parotid gland pleomorphic adenoma: a case report

BACKGROUND

Pleomorphic adenoma is the most common neoplasm of the parotid gland. It is a benign tumor composed of epithelial and myoepithelial cells arranged in various morphological patterns. The most common reasons contributing to a recurrent disease are obvious or underestimated tumor spillage, incomplete excision, and violation of the pseudocapsule of the tumor.

CASE REPORT

This article presents a case of gross multinodular recurrence of a parotid gland pleomorphic adenoma in a 38-year-old female patient. Upon clinical examination of the homolateral neck, multiple, painless, well-defined, palpable, nontender masses and subcutaneous nodules of the right parotid and homolateral neck region were revealed. The patient was treated with surgery and subsequent radiation therapy. Histologic examination of the resected specimen was suggestive of a recurrent pleomorphic adenoma disease. There were no signs of malignant transformation in the specimen. The diagnostic procedure followed, and management of the patient is outlined in the paper.

DISCUSSION

Pleomorphic adenoma is the most common tumor of the parotid gland. In spite of being a benign neoplasm, inadequate management of the lesion may lead to problems such as local recurrence or malignant transformation. Management of recurrent tumors is challenging because the probability of subsequent recurrence increases with each recurrent episode, thus making local control increasingly difficult and damage to the facial nerve more likely.

Extra-major salivary gland pleomorphic adenoma of the head and neck: a 10-year experience and review of the literature

Pleomorphic adenomas, or benign mixed tumors, make up 65% of all salivary gland tumors. They also can be found as solid tumors in other parts of the head and neck region, such as the auditory canal, the eyelids, and the orbital area. In this study, we investigated extra-major salivary gland pleomorphic adenomas of the head and neck region retrospectively at a tertiary care center. Between March 1998 and June 2009, 37 patients underwent primary surgery for extra-major salivary gland pleomorphic adenoma of the head and neck. The duration of symptoms, radiographic findings, operative procedures, and pathologic findings were documented. Of the 37 patients enrolled, 22 were male and 15 were female, with a median age of 57 years. Tumors were found in the soft palate, hard palate, nasopharynx, orbital area, trachea, buccal mucosa, cheek, nasal septum, upper lip, lower eyelid, and external auditory canal. Cellular variant of the pleomorphic adenoma was found in four patients, while the remaining patients presented with the classic variant. No myxoid subgroup was noted in our study. Carcinoma ex pleomorphic adenoma was observed only in one patient for whom radical surgery was performed. Twenty-eight patients (76%) had long-term follow-ups, with the average follow-up period being 4.5 years. Local recurrence was observed in three patients, and they underwent revision surgery during the follow-up period. Our results indicate that extra-major salivary gland pleomorphic adenomas are most commonly found in the soft palate. Wide excision was the treatment of choice, although its efficacy might be compromised with cosmetics and functional structures of the head and neck. Therefore, long-term follow-up of patients is necessary.

Superficial parotidectomy versus retrograde partial superficial parotidectomy in treating benign salivary gland tumor (pleomorphic adenoma)

PURPOSE

Of all benign salivary gland tumors of the parotid gland, pleomorphic adenoma (mixed tumor) is the most common. It accounts for 60% to 70% of all benign tumors of the parotid gland. This neoplasm arises in patients in the fourth to sixth decade of life, with a female predominance. The surgical excision of this lesion continues to be the subject of major debate. The goal is to avoid facial disability yet attain complete resection without perforation of the capsule/pseudocapsule. The purpose of our study is to compare 2 surgical techniques performed at the Ear, Nose, and Throat and Maxillofacial Departments, Rambam Medical Center, Haifa, Israel, and determine which is preferable in treating this lesion.

PATIENTS AND METHODS

We reviewed 48 patients who underwent excision of pleomorphic adenoma of the parotid gland between 1996 and 2005 at Rambam Medical Center: 18 were treated surgically with the classical superficial parotidectomy (SP) technique, using an anterograde approach, and 30 were treated with retrograde partial superficial parotidectomy (PSP). We compared the 2 surgical techniques in terms of surgical time, histopathologic size of the lesion, amount of excised healthy parotid tissue, histologic margin, and the preservation of the capsule/pseudocapsule. We also made clinical records of temporary or definitive injury to the facial nerve, which branches of the facial nerve were temporarily or definitively injured, the occurrence of Frey syndrome, esthetic satisfaction, and the amount of recurrence or infection after surgery.

RESULTS

Of the 48 patients, 19 (39.6%) were male and 29 (60.4%) were female, with a mean age (+/- SD) of 43.8 +/- 16.97 years (median, 50 years; range, 12-79 years). We found a significant difference (P = .029) in mean surgical time (+/- SD): 171 +/- 49.7 minutes (median, 165 minutes) when performing the classical SP and 145 +/- 42.7 minutes (median, 130 minutes) when performing the retrograde PSP. Much more healthy parotid tissue was taken out with the classical procedure (mean, 51.4 +/- 13.6 mm; median, 50 mm) than with the retrograde PSP technique (mean, 39.2 +/- 11.8; median, 35 mm) (P = .01). There was a significant difference (P = .0003) in facial nerve injuries: 39% of patients did not report any facial deficit in the SP group compared with 90% in the PSP group. In the SP group, only 3 patients reported a permanent deficit, and in the PSP group, only 3 patients had a temporary deficit (compared with 8 in the SP group). The main injuries occurred in the mandibular branch with both techniques: 6 SP and 2 PSP. There was no difference in esthetic satisfaction: 72.2% of patients in the SP group and 80% in the PSP group had no esthetic complaints. In the SP group, patients mainly complained about swelling (3 patients), and in the retrograde PSP group, the main complaint was depression (4 patients). Frey syndrome was found in 9 patients in the retrograde PSP group and 4 in the classical SP group (with an overall rate of 27.7%). The lesion recurred in only 2 patients--1 in each group.

CONCLUSION

With both of the techniques, we found satisfactory results. In the majority of cases, retrograde PSP is a superior technique to the classical SP, although Frey syndrome is more often observed with the former.

Parotidectomy in children: indications and complications

Background:

Parotidectomy in children is uncommon, and surgeons face specific challenges not encountered in adult practice.

Method:

Retrospective review of parotidectomies performed in our paediatric hospital over a 10-year period (1999–2008).

Results:

Twenty-one children underwent 22 parotidectomies, of which six were total. The following pathology was encountered: atypical mycobacterial infection (8.38 per cent), pleomorphic adenoma (4.19 per cent), lymphatic malformation (2.10 per cent), haemangioma (2 per cent), first branchial cleft anomaly (2 per cent), follicular non-Hodgkin's lymphoma (2 per cent) and lipoblastoma (1.5 per cent). No cases of permanent facial nerve palsy occurred. Mild transient facial nerve palsy occurred in five patients (23 per cent), gustatory sweating in four (19 per cent) and hypertrophic scarring in three (14 per cent).

Conclusion:

We discuss the range of parotid pathology found in children, the approach to investigation, the surgical difficulties encountered, and ways to reduce the apparently higher rate of complications encountered. Parotid surgery in children should be concentrated in the hands of a small number of surgeons with a particular interest in this area.

Clinical manifestations of recurrent parotid pleomorphic adenoma

Objectives

This study was undertaken to confirm the clinical characteristics of recurrent pleomorphic adenoma (RPA), and to identify those factors that affect the development of malignant transformation (MT) from RPA.

Methods

The medical records of 270 patients, who were operated upon for parotid PA, were retrospectively reviewed. The pathologic specimens of a selected series of 23 patients were reviewed for histologic subtype and microscopic multi-nodularity.

Results

Mean age of initial operation in RPA without MT (RPA^-MT) group was significantly lower than that of primary PA group. Mean age of the revision operation in RPA with MT (RPA^+MT) group was significantly greater than that of RPA^-MT group. Mean interval from operation to recurrence shortened after each revision operation. The risk of MT and additional recurrence increased significantly with recurrence. In RPA^-MT group tumor recurrence occurred in 21.4% of patients despite a clear resection margin.

Conclusion

The risk factors for MT may be an age of over 45 yr and multiple recurrences. However, younger patients are more at risk of recurrence. A clear resection margin cannot guarantee a cure in RPA, and it seems that parotid pleomorphic adenomas slowly gain malignant characteristics after repeated recurrences.

Metastasizing Pleomorphic Adenoma of the Salivary Gland

Metastasizing pleomorphic adenoma of salivary glands is a group of rare tumors that are histologically identical to benign mixed tumors and that inexplicably metastasize. A review of the literature revealed that it usually occurs after multiple local recurrences, and the interval between diagnosis of primary pleomorphic adenoma and metastases ranges between 3 and 52 years. The most common site for metastasis is bone, followed by the head and neck and lung. No histologic or molecular parameters exist at the present time that could predict the development of metastasis in these neoplasms. Metastasectomy confers significant survival advantage over nonoperative treatment for localized and accessible metastases, but there is no definite treatment protocol available in cases of widespread metastases.

[A 20-year retrospective histoclinical analysis of parotid gland tumors in the ENT Department AM in Katowice]

INTRODUCTION

Salivary gland neoplasms represent the diverse group of tumours encountered by the head and neck surgeons.

MATERIAL AND METHODS

The study is analysis of 531 patients with parotid gland tumours in patients treated in ENT Department during 1986-2006. We analysed surgical treatment and intraoperative tumour stage. The results of histological diagnosis were presented.

RESULTS

The frequency of incidence of benign neoplasm was 80%. The most frequent tumour was pleomorphic adenoma--75% and adenolymphoma--16%. Malignant tumours constituted 20% of all gland tumours. Mucoepidermoid (27%) and adenoid cyst (22%) carcinomas were the most common malignant tumour. Tumour stages T3-T4 was in 90%.

Management and prognostic factors of recurrent pleomorphic adenoma of the parotid gland: personal experience and review of the literature

The aim of this study was to investigate the management and prognostic determinants of recurrent pleomorphic adenoma (RPA). A retrospective analysis was performed to examine the clinical features, the prevalence of surgical complications, and new recurrences of RPA. Tumor recurrence rate was estimated by the Kaplan–Meier method, and the prognostic value of some of the variables was tested by univariate analysis using the log rank test. The study focused on 33 patients, 18 female (54.5%) and 15 male (45.5%), aged 12–71 years (median 41). A total or extended total parotidectomy was performed in 16 cases (48.5%), a superficial parotidectomy in 10 cases (30.3%), and a local excision in 7 cases (21.2%). In ten patients (30.3%), a branch or the trunk of the facial nerve was deliberately sacrificed. Major complications included one unexpected definitive paralysis of the marginal mandibular branch of the facial nerve and 14 cases of Frey syndrome. Follow-up varied from 2 to 25 years (median 10.5 years), and there were 11 new recurrences (33.3%) within a period varying from 1 to 16 years (median 6 years). The estimated tumor recurrence rates were 14.1 ± 6.6% at 5 years, 31.4 ± 9.4% at 10 years, 43.0 ± 10.8% at 15 years, and 57.2 ± 14.8% at 20 years. Presence of a multinodular lesion and the type of intervention performed were significantly associated with a higher probability of recurrence. RPAs are prone to new recurrences, especially when multinodular and treated with a local excision. Surgical treatment should include facial nerve resection in selected cases. Follow-up for the patient’s lifetime is warranted.

Recurrent pleomorphic adenoma of the parotid gland: Analysis of 108 consecutive patients

BACKGROUND

Surgery for recurrent parotid pleomorphic adenoma is a challenging problem.

METHODS

One hundred eight patients who underwent 134 reoperations for recurrent parotid pleomorphic adenoma (follow-up, 22 years) were evaluated for histopathologic features and risk factors for recurrence.

RESULTS

The number of reoperations for tumor recurrence ranged from 1 to 10. Twenty-seven patients (25%) developed permanent facial nerve weakness. The risks for clinically evident rerecurrence after 1, 5, and 15 years were 16%, 42%, and 75%, respectively. Female sex, young age at initial treatment, and enucleation instead of parotidectomy for treatment of the first recurrence were significant risk factors for rerecurrence. The mean number of recurrent tumor nodules was 26.

CONCLUSIONS

Surgery for recurrent parotid pleomorphic adenoma has a high rate of facial nerve morbidity. The chance of rerecurrence is high. Extended parotidectomy seems to be the best approach for the reoperation to reduce the risk of rerecurrence.

Role of limited parotidectomy in management of pleomorphic adenoma

There is continued controversy over the extent of parotidectomy required for removal of a benign pleomorphic adenoma from the parotid gland. Currently, consensus exists that the integrity of the facial nerve must be preserved when the tumour is totally removed.

As a result of experience gained in the first half of the twentieth century, it was recommended that superficial parotidectomy with facial nerve dissection should be the minimal biopsy for pleomorphic adenoma. Since that time, however, research has indicated that partial parotidectomy or extracapsular dissection of benign pleomorphic adenoma can be accomplished with preservation of the facial nerve without an increase in tumour recurrence. Partial parotidectomy or extracapsular dissection results in impaired cosmetic results and a lower incidence of Frey's syndrome, and thus may be the preferred approach when undertaken by experienced surgeons.

Pleomorphic adenoma of the submandibular gland: an evolving change in practice following review of a personal case series

We reviewed patients with submandibular gland pleomorphic adenoma treated at a tertiary referral centre in the United Kingdom (1988-2004). Thirty-seven patients were identified, 32 newly diagnosed cases and 5 cases of recurrent disease previously treated elsewhere. The exact pre-operative diagnosis was "unknown" in 76% of the new cases. All cases were surgically excised (41% with extracapsular gland excision and 59% by selective level Ib, IIa and III neck dissection). Temporary marginal mandibular nerve neuropraxia was documented in 25% of cases. All 32 new cases remain clinically tumour free at the time of writing. In patients with recurrent disease, complete microscopic tumour clearance was achieved in three of the five cases, however all remain clinically tumour free. Pleomorphic adenomas of the submandibular gland are uncommon, with good prognosis following complete tumour excision. Recurrent tumours, however, are frequently multi-focal and difficult to excise completely. The adequacy of primary surgery is crucial and supports an approach for a more radical excision primarily by a selective level lb, IIa and III neck dissection; ensuring complete disease clearance for pleomorphic adenoma, avoiding the risks of tumour spillage associated with a limited excision and tumour handling; and removing the primary echelon of lymph nodes at risk of metastasis if the pathology turns out to be malignant.

'Metastasizing pleomorphic salivary adenoma' should now be considered a low-grade malignancy with a lethal potential

PURPOSE OF REVIEW

To review the current knowledge on the clinical entity of metastasizing pleomorphic adenoma.

RECENT FINDINGS

Using case studies, the literature continues to explore the potential to identify a chromosomal abnormality that might explain the clinical entity, and may constitute a submicroscopic malignant transformation with molecular genetic alterations. Presently there are no agreed histopathological parameters that can identify or confirm a difference in behavior between the 'common' pleomorphic adenoma from the metastasizing pleomorphic adenoma.

SUMMARY

The evidence supports that metastasizing pleomorphic adenoma is most likely to be an unrecognized and as yet unclassified malignant neoplasm and as such must be considered a low-grade, potentially lethal malignant disease when it presents, which may constitute a submicroscopic malignant transformation with molecular genetic alterations. Further research is required to answer the many questions.

Recurrent pleomorphic adenoma of the parotid gland

BACKGROUND

Surgery of recurrent pleomorphic adenoma presents an increased risk of facial nerve injury and a considerable re-recurrence rate.

METHODS

A series of 33 patients with first recurrence of pleomorphic adenoma of the parotid gland was analyzed. The data were derived from medical records as well as from interviews and clinical examinations of all living patients. Histologic material of the initial and recurrent tumor were reviewed.

RESULTS

Multifocal recurrence and carcinoma in pleomorphic adenoma were observed in 73% and 9% of patients, respectively. The incidence of permanent partial facial nerve injury after surgery was 23% in patients with initial enucleation and 14% in those with initial superficial parotidectomy (including 1 patient with facial nerve resection and 1 patient with a partial facial paresis before recurrence surgery). A subsequent recurrence occurred in 6 patients, all with initial enucleation after a mean time interval of 9 years.

CONCLUSIONS

The preservation of the facial nerve was possible in all but 1 patient treated for the first recurrence with a relatively low rate of permanent partial facial paresis because of the use of the operating microscope and facial nerve monitor. To evaluate the re-recurrence rate, a follow-up of at least 10 years is necessary.

Recurrent Pleomorphic Adenoma of the Parotid Gland: A Prospective Histopathological and Immunohistochemical Study

OBJECTIVES/HYPOTHESIS

Histopathological characteristics and proliferation indices of recurrent pleomorphic adenoma were described in a series of 31 patients who were referred to the authors' clinic for revision surgery.

STUDY DESIGN

Prospective series of 31 patients.

METHODS

Serial sections of surgical specimen using the whole-organ sectioning technique were carried out for light microscopic examination after total parotidectomy and periparotid fat resection. The nodules were examined with special reference to localization, amount, size, histological subtypes, capsular alterations, and the amount of nodule spilling. Expression of proliferation markers (Ki67/MIB-1) according to the size and histological subtypes of the nodules was also investigated.

RESULTS

Most recurrences were multinodular, and the number of nodules was much higher than expected, ranging from 1 to 157. The myxoid subtype was predominant. Eighty percent of the patients exhibited widely distributed nodules also lying outside the scar. These nodules contained only a thin pseudocapsule and often lacked complete encapsulation. The majority of multinodular recurrences of parotid pleomorphic adenoma consisted of small nodules (less than 1 mm in diameter). Smaller nodules showed similar or higher levels of proliferative activity than larger nodules.

CONCLUSION

The extended multifocal distribution of tumor recurrences after insufficient resection of pleomorphic adenoma (most often after enucleation) can explain a high incidence of further recurrences. Therefore, a total parotidectomy including removal of surrounding fat tissue seems to be appropriate for the initial treatment of recurrent pleomorphic adenoma.