Histocytologic grading of mucoepidermoid carcinoma of major salivary glands in prognosis and survival: a clinicopathologic and flow cytometric investigation

Prognostic Effect of Neck Dissection and Risk Factors for Occult Lymph Node Metastasis in cN0 Parotid Carcinoma

Objective

This study aimed to explore the prognostic effect of neck dissection and to identify risk factors associated with occult lymph node metastasis (OLNM) in clinically node-negative (cN0) parotid carcinoma (PC).

Methods

A retrospective analysis was conducted on cN0 PC patients who underwent primary surgery at the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, between 2012 and 2022. Kaplan-Meier (KM) survival analyses were carried out to evaluate differences in progression-free survival (PFS) and overall survival (OS) between patients undergoing neck dissection and those who did not. Clinical variables associated with OLNM in the neck dissection group were assessed using univariate and multivariate logistic regression analyses.

Results

Among 472 PC patients, 133 were classified as cN0 following initial surgery, of whom 75 (56.4%) underwent neck dissection. Pathological lymph node metastases were confirmed in 20 (26.7%) patients in the neck dissection cohort. Poor tumor differentiation was identified as an independent risk factor for OLNM (p = 0.017). No significant differences in PFS or OS were observed between the no-neck dissection and neck dissection groups for patients with low-grade or well-differentiated tumors (p > 0.05). However, neck dissection was associated with significantly prolonged PFS in patients with tumors of higher grade or low to moderate differentiation (p < 0.05). Notably, OS did not improve with neck dissection across all subgroups (p > 0.05).

Conclusion

Poorly differentiated tumors in cN0 PC are independently associated with a higher risk of OLNM. While prophylactic neck dissection may enhance PFS in patients with higher grade or poorly differentiated tumors, it does not confer a survival benefit in terms of OS. These findings support the selective use of neck dissection in patients with higher risk tumor profiles.

Mucoepidermoid carcinoma of the anterior lingual salivary gland: A rare case report

Mucoepidermoid carcinomas (MECs) are rare head and neck malignant tumours that were originally considered to be benign. It has been estimated that ~20% of MECs in the major salivary glands, such as the parotid gland, and 50% in the several minor salivary glands found in the oral cavity, are malignant. The diagnosis of MECs is mainly based on ancillary and immunohistochemistry testing. However, owing to the difficulty in harvesting adequate material for histological examination, the histopathological diagnosis of intraoral MECs may be particularly challenging. We herein report a rare case of an 82-year-old patient who presented to the Department of Oral and Maxillofacial Surgery of Ryukyu University Hospital with complaints of a progressive swelling and pain in the ventral surface of the apex of the tongue. The patient had previously undergone needle biopsy and the histopathological analysis of the tumour suggested a diagnosis of irritation fibroma. To ensure a more accurate histopathological assessment, an incisional biopsy was performed, in addition to the haematological and radiological assessments. Examination of the obtained surgical specimen confirmed low-grade MEC of the anterior lingual gland. The tumour was surgically excised, the patient healed uneventfully and no recurrence was detected on the regular 3-year follow-up. Although MECs are relatively more common in the minor salivary glands of the oral cavity, they are a rare occurrence in the anterior lingual gland. Therefore, adequate histological material should be surgically harvested to perform a complete evaluation of the morphology and cytology of the tumour and ensure the accuracy of diagnosis.

Adenocarcinoma of the minor salivary gland with concurrent MAML2 and EWSR1 alterations

Salivary gland tumors are histologically diverse, and each entity has distinctive histopathological and molecular features. We report two cases of salivary gland tumors with unique histological and molecular findings, which have not been documented previously. The tumors were located in the base of the tongue in both patients. Most tumor cells were arranged in cords and nests, giving a trabecularlike appearance. Focally, glandular structures with intraluminal mucin and perivascular pseudorosette-like configurations were identified. Tumor cells had eosinophilic to clear cytoplasm, and showed mild nuclear atypia. They were positive for pancytokeratin and negative for S-100, p63, c-KIT, androgen receptor, and neuroendocrine markers. Multiple foci of capsular or lymphovascular invasion were identified, but the Ki-67 labeling index was low (< 5%). Fluorescence in situ hybridization revealed concurrent alterations of MAML2 and EWSR1 gene. Further investigations with a larger number of cases with similar histological and molecular features will accurately classify this tumor.

NDRG2 ablation reprograms metastatic cancer cells towards glutamine dependence via the induction of ASCT2

Background: Metastasis is the most common cause of lethal outcome in various types of cancers. Although the cell proliferation related metabolism rewiring has been well characterized, less is known about the association of metabolic changes with tumor metastasis. Herein, we demonstrate that metastatic tumor obtained a mesenchymal phenotype, which is obtained by the loss of tumor suppressor NDRG2 triggered metabolic switch to glutamine metabolism.

Methods: mRNA-seq and gene expression profile analysis were performed to define the differential gene expressions in primary MEC1 and metastatic MC3 cells and the downstream pathways of NDRG2. NDRG2 regulation of Fbw7-dependent c-Myc stability were determined by immunoprecipitation and protein half-life assay. Luciferase reporter and ChIP assays were used to determine the roles of Akt and c-Myc in mediating NDRG2-dependent regulation of ASCT2 in in both tumor and NDRG2-knockout MEF cells. Finally, the effect of the NDRG2/Akt/c-Myc/ASCT2 signaling on glutaminolysis and tumor metastasis were evaluated by functional experiments and clinical samples.

Results: Based on the gene expression profile analysis, we identified metastatic tumor cells acquired the mesenchymal-like characteristics and displayed the increased dependency on glutamine utilization. Further, the gain of NDRG2 function blocked epithelial-mesenchymal transition (EMT) and glutaminolysis, potentially through suppression of glutamine transporter ASCT2 expression. The ASCT2 restoration reversed NDRG2 inhibitory effect on EMT program and tumor metastasis. Mechanistic study indicates that NDRG2 promoted Fbw7-dependent c-Myc degradation by inhibiting Akt activation, and subsequently decreased c-Myc-mediated ASCT2 transcription, in both tumor and NDRG2-knockout MEF cells. Supporting the biological significance, the reciprocal relationship between NDRG2 and ASCT2 were observed in multiple types of tumor tissues, and associated with tumor malignancy.

Conclusions: NDRG2-dependent repression of ASCT2 presumably is the predominant route by which NDRG2 rewires glutaminolysis and blocks metastatic tumor survival. Targeting glutaminolytic pathway may provide a new strategy for the treatment of metastatic tumors.

Pathologic grading of mucoepidermoid carcinomas of the salivary gland and its effect on clinicopathologic follow-up: an institutional experience

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor. Differences inprognosis can be noted owing to the tumor grade determined using multiple grading schemes (2-tier: low- and high-grade vs. 3-tier: low-, intermediate-, and high-grade). We studied clinicopathologic features of MEC using a 3-tier grading system and retrospectively categorized cytologic diagnoses as per the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC).A total of 69 cases of MEC were identified, and most were seen in the parotid gland. Aggressive clinical behavior was seen in high-grade MEC compared with intermediate- and low-grade MEC. By fluorescence in situ hybridization (FISH) analysis, MAML2 rearrangements were seen in 78% of cases.The MSRSGC subcategorized the majority (63.8%) of MEC as salivary gland neoplasm of uncertain malignant potential, suspicious for malignancy, or malignant. Clustering intermediate- with low-grade cases did not significantly impact the clinical behavior. Both high-grade and oncocytic MEC can be MAML2 FISH negative.

Ceruminous Neoplasms of the Ear

Ceruminous glands are modified apocrine glands located in the external auditory canal (EAC). Neoplastic lesions arising from these glands are rare in humans and constitute a major differential diagnosis for glandular neoplasms of the EAC. Due to anatomic restrictions, benign and malignant neoplasms present with similar symptoms and to some extent even comparable radiologic features, particularly when the tumors are localized. Biopsies are frequently limited by small size, fragmentation and improper anatomic and architectural orientation, thereby hampering our ability to appreciate the relationship of peripheral edges of the tumor to the surrounding tissue. Benign and malignant tumors may also have overlapping histomorphologic features, which further magnifies the challenges in accurate diagnosis and management strategies. This article summarizes the salient clinical, radiologic and histologic features of common ceruminous gland tumors, in addition to discussing features that can aid in differentiating ceruminous tumors from other EAC tumors and to distinguish benign from malignant entities.

Cystadenoma of Minor Salivary Gland With Cervical Metastasis: Benign or Malignant?

A cystadenoma originating in the salivary gland is a rare neoplasm that can originate from the major or minor salivary glands. Although this tumor has the potential to recur if it is incompletely excised, it has been regarded as a benign tumor because it has not been determined to be associated with local tissue destruction or metastasis. This report serves as an update to the current understanding of cystadenoma. The patient in this case study presented with a recurrent painless mass in her left retromolar and submandibular regions that had persisted for more than 2 years. Histologic analysis showed that this lesion was a recurrent cystadenoma of the minor salivary gland, with cervical lymph nodes testing positive for tumor cells. After more than 3 years of clinical follow-up, no signs of recurrence were observed. A case of cystadenoma with cervical metastasis is presented; further attention should be paid to patients with recurrent cystadenoma that also might contain lymph node metastasis.

Silymarin and its active component silibinin act as novel therapeutic alternatives for salivary gland cancer by targeting the ERK1/2-Bim signaling cascade

PURPOSE

Approximately 20% of all salivary gland cancer patients who are treated with current treatment modalities will ultimately develop metastases. Its most common form, mucoepidermoid carcinoma (MEC) is a highly aggressive tumor with an overall 5-year survival rate of ~30%. Until now, several chemotherapeutic drugs have been tested for the treatment of salivary gland tumors, but the results have been disappointing and the drugs often cause unwanted side effects. Therefore, several recent studies have focused on the potential of alternative and/or complementary therapeutic options, including the use of silymarin.

METHODS

The effects of silymarin and its active component silibinin on salivary gland cancer-derived MC3 and HN22 cells and their underlying molecular mechanisms were examined using trypan blue exclusion, 4'-6-diamidino-2-phenylindole (DAPI) staining, Live/Dead, Annexin V/PI staining, mitochondrial membrane potential (ΔΨm) measurement, quantitative RT-PCR, soft agar colony formation and Western blotting analyses.

RESULTS

We found that silymarin and silibinin dramatically increased the expression of the pro-apoptotic protein Bim in a concentration- and time-dependent manner and, concomitantly, induced apoptosis in MC3 and HN22 cells. We also found that ERK1/2 signaling inhibition successfully sensitized these cells to the apoptotic effects of silymarin and silibinin, which indicates that the ERK1/2 signaling pathway may act as an upstream regulator that modulates the silymarin/silibinin-induced Bim signaling pathway.

CONCLUSIONS

Taken together, we conclude that ERK1/2 signaling pathway inhibition by silymarin and silibinin increases the expression of the pro-apoptotic Bcl-2 family member Bim which, subsequently, induces mitochondria-mediated apoptosis in salivary gland cancer-derived cells.

Clinical Presentation, Management, and Outcome of High-Grade Mucoepidermoid Carcinoma of the Parotid Gland

OBJECTIVE: To describe clinical features of high-grade (HG) mucoepidermoid carcinoma (MEC) of the parotid gland and assess clinical outcomes of one surgical management approach.

DESIGN/SETTING/METHODS: Retrospective case series in a tertiary care academic institution. Pathology records were reviewed from 1977 to 1997, identifying patients with parotid HG MEC. Available medical records were reviewed for data on clinical features, treatment, and outcome.

RESULTS: Increased stage, increased T stage, presence of neck metastasis, and distant metastasis were all associated with poor outcome. Wide local excision and postoperative radiation (XRT) provided 82% local control. XRT alone for N0 disease provided 86% regional control, while XRT and neck dissection yielded 74% control in N+ cases.

CONCLUSION: High-grade MEC of the parotid gland is an aggressive disease that frequently presents at advanced stage. Parotidectomy with modified radical neck dissection and postoperative XRT provides reasonable local and regional control for patients with N+ disease. Elective selective neck dissection and radiation should be considered for T3 and T4 tumors with N0 status.

Nuclear Multidrug Resistance-Related Protein 1 Is Highly Associated with Better Prognosis of Human Mucoepidermoid Carcinoma through the Suppression of Cell Proliferation, Migration and Invasion

Objectives

Multidrug resistance-related protein 1 (MRP1) overexpression is a well acknowledged predictor of poor response to chemotherapy, but MRP1 also correlated to better prognosis in some reports, especially for patients not pretreated with chemotherapy. In our previous study, we found nuclear translocation of MRP1 in mucoepidermoid carcinoma (MEC) for the first time. The purpose of this study was to further investigate the function of nuclear MRP1 in MEC.

Materials and Methods

Human MEC tissue samples of 125 patients were selected and stained using immunohistochemistry. The expression level of total MRP1/nuclear MRP1 of each sample was evaluated by expression index (EI) which was scored using both qualitative and quantitative analysis. The correlations between the clinicopathologic parameters and the EI of nuclear MRP1 were analyzed using Spearman’s rank correlation analysis, respectively. The effects of RNAi-mediated downregulation of nuclear MRP1 on MEC cells were assessed using flow cytometric analysis, MTT assay, plate colony formation assay, transwell invasion assay and monolayer wound healing assay.

Results

In this study, we found the EI of nuclear MRP1 was negatively correlated to the pathologic grading (r = -0.498, P<0.01) / clinical staging (r = -0.41, P<0.01) / tumor stage (r = -0.28, P = 0.02) / nodal stage (r = -0.29, P<0.01) of MEC patients. The RNAi-mediated downregulation of nuclear MRP1 further proved that the downregulation of nuclear MRP1 could increase the cell replication, growth speed, colony formation efficiency, migration and invasion ability of MEC cells.

Conclusion

Our results suggested that nuclear MRP1 is highly associated with better prognosis of human mucoepidermoid carcinoma and further study of its function mechanism would provide clues in developing new treatment modalities of MEC.

Prognostic features in mucoepidermoid carcinoma of major salivary glands with emphasis on tumour histologic grading

AIMS

To compare the different grading systems of mucoepidermoid carcinoma (MEC) and identify the most reliable and objective histopathologic features predictive of outcome.

METHODS AND RESULTS

Seventy-two cases diagnosed as MEC were subjected to a meticulous histopathologic re-review. 20 of 72 (28%) cases were originally misdiagnosed as MEC including 16 as high grade (HG). Among the 52 confirmed MEC, median follow up (FU) was 59 months. Mitosis (≥4/10 High Power Fields), necrosis, pleomorphism, focal keratinization, desmoplasia, and lymph node metastasis were associated with adverse disease specific survival (DSS) and recurrence free survival (RFS) (P < 0.002). In all grading systems, low and intermediate grade had similar DSS and RFS but much better outcome than HG (P < 0.007). All patients with tumour harboring low mitotic rate and no necrosis did not recur except for one patient with a positive margin. All cases with high mitotic rate and necrosis died or recurred.

CONCLUSIONS

The majority of previously diagnosed HG MEC cases are misclassified. There is no difference in outcome between low and intermediate grade in all grading schemes. Consideration should be given to stratify MEC based on relatively objective criteria such as mitosis and necrosis.

Effect of clinical symptoms on the indication for selective neck dissection for N0 carcinomas of the parotid gland

Lymph node metastasis is a major prognostic factor in parotid carcinoma, however, the pre-operative diagnosis of occult nodal metastasis is difficult in clinical N0 (cN0) parotid cancer patients. In addition, the indication of neck dissection in T1-3 cN0 patients is controversial. The current study investigated 17 patients with clinical T1-3 cN0 parotid cancer, and analyzed the correlation between patient symptoms/findings and pathological N status/tumor histological grade. In the statistical analysis, pain was found to significantly correlate with neck metastasis. Furthermore, cN0-staged patients without pain exhibited no neck metastasis. However, no significant correlation was identified between patient symptoms or findings and histological grade. These results indicate the possibility that selective neck dissection can be omitted for T1-3 cN0-staged patients without pain.

Salivary mucoepidermoid carcinoma revisited

Clinicopathological features, prognosis and therapeutic strategies for mucoepidermoid carcinoma originating in salivary and salivary-type glands of the head and neck are reviewed. We emphasise histopathological aspects, appraise the value of histochemistry, electron microscopy, immunohistochemistry and cytophotometry, and discuss histogenesis and characteristic gene translocations. We additionally consider possible diagnostic difficulties, problems related to histological grading and accuracy of existing literature, and areas of controversy or uncertainty which may benefit from further investigations.

Nuclear multidrug-resistance related protein 1 contributes to multidrug-resistance of mucoepidermoid carcinoma mainly via regulating multidrug-resistance protein 1: a human mucoepidermoid carcinoma cells model and Spearman's rank correlation analysis

Background

Multidrug resistance-related protein 1 (MRP1/ABCC1) and multidrug resistance protein 1 (MDR1/P-glycoprotein/ABCB1) are both membrane-bound drug transporters. In contrast to MDR1, MRP1 also transports glutathione (GSH) and drugs conjugated to GSH. Due to its extraordinary transport properties, MRP1/ABCC1 contributes to several physiological functions and pathophysiological incidents. We previously found that nuclear translocation of MRP1 contributes to multidrug-resistance (MDR) of mucoepidermoid carcinoma (MEC). The present study investigated how MRP1 contributes to MDR in the nuclei of MEC cells.

Methods

Western blot and RT-PCR was carried out to investigate the change of multidrug-resistance protein 1 (MDR1) in MC3/5FU cells after MRP1 was downregulated through RNA interference (RNAi). Immunohistochemistry (IHC) staining of 127 cases of MEC tissues was scored with the expression index (EI). The EI of MDR1 and MRP1 (or nuclear MRP1) was analyzed with Spearman's rank correlation analysis. Using multiple tumor tissue assays, the location of MRP1 in other tissues was checked by HIC. Luciferase reporter assays of MDR1 promoter was carried out to check the connection between MRP1 and MDR1 promoter.

Results

MRP1 downregulation led to a decreased MDR1 expression in MC3/5FU cells which was caused by decreased activity of MDR1 promoter. IHC study of 127 cases of MEC tissues demonstrated a strong positive correlation between nuclear MRP1 expression and MDR1 expression. Furthermore, IHC study of multiple tumor tissue array sections showed that although nuclear MRP1 widely existed in MEC tissues, it was not found in normal tissues or other tumor tissues.

Conclusions

Our findings indicate that nuclear MRP1 contributes to MDR mainly through regulating MDR1 expression in MEC. And the unique location of MRP1 made it an available target in identifying MEC from other tumors.

Mucoepidermoid carcinoma of the parotid gland treated by surgery and postoperative radiation therapy: clinicopathologic correlates of outcome

OBJECTIVES/HYPOTHESIS

To determine clinical and pathological correlates of outcome among patients treated by surgery and postoperative radiation therapy for mucoepidermoid carcinoma of the parotid gland.

STUDY DESIGN

Retrospective review.

METHODS

The medical records of 61 patients treated by surgery and postoperative radiation therapy for localized mucoepidermoid carcinoma of the parotid gland were retrospectively reviewed in an attempt to identify clinicopathologic correlates of overall survival. Secondary endpoints included local-regional control, distant metastasis-free survival, and complications.

RESULTS

The 3- and 5-year estimates of overall survival were 85% and 79%, respectively. Multivariate analysis identified high tumor grade (hazard ratio [HR] = 7.92) and T4 disease (HR = 3.35) as independent predictors of decreased survival, with the former also predicting for distant metastasis and the latter predicting for local-regional recurrence. The 5-year estimate of overall survival was 83% for patients with non-high-grade tumors, compared to 52% for those with high-grade histology (P = 0.001). Late complications included trismus (2 patients), osteoradionecrosis (1 patient), and hearing loss (1 patient).

CONCLUSION

Patients with high-grade tumors and T4 disease are at increased risk for treatment failure after surgery and postoperative radiation therapy for mucoepidermoid carcinoma of the parotid gland. Investigative strategies to improve outcome should be considered for these particular patients in the future.

Parotid carcinoma: Current diagnostic workup and treatment

In this review we present recent progress in diagnostic workup, prognostic evaluation, treatment options and resulting outcomes. Whenever possible, complete resection remains the mainstay of treatment. Sacrifice of facial nerve branches is reserved for the clinically or electromyographically dysfunctioning facial nerve. Clinical or radiological neck disease demands combined surgery and radiotherapy. Treatment of the N0 neck is indicated for advanced stage-high grade tumors but the question remains unanswered whether this should be surgical or radiotherapeutic elective treatment. Surgery alone will cure low stage, low grade tumors, that show no additional negative prognostic factors following adequate resection. In all other tumors postoperative radiotherapy will improve locoregional control. This approach results in good locoregional control, in a way that distant metastasis remains the typical presentation of treatment failure. In this setting, the results of systemic treatment today remain limited, but a huge effort in the molecular biology field has been done to introduce targeted therapy into this domain of head and neck cancer. Disease control remains variable within the patient population. This variation can increasingly be predicted by systems that incorporate the combined information of multivariately identified and quantified prognostic factors into an individualized prognosis for the parotid carcinoma patient.

Unfavorable prognosis of CRTC1-MAML2 positive mucoepidermoid tumors with CDKN2A deletions

The CRTC1-MAML2 fusion oncogene underlies the etiology of mucoepidermoid salivary gland carcinoma (MEC) where it confers a favorable survival outcome as compared with fusion-negative MEC. While these analyses suggested that detection of CRTC1-MAML2 serves as a useful prognostic biomarker, we recently identified outlier cases of fusion-positive MEC associated with advanced-staged lethal disease. To identify additional genetic alterations that might cooperate with CRTC1-MAML2 to promote disease progression, we performed a pilot high-resolution oligonucleotide array CGH (aCGH) and PCR-based genotyping study on 23 MEC samples including 14 fusion-positive samples for which we had clinical outcome information. Unbiased aCGH analysis identified inactivating deletions within CDKN2A as a candidate poor prognostic marker which was confirmed by PCR-based analysis (CDKN2A deletions in 5/5 unfavorable fusion-positive cases and 0/9 favorable fusion-positive cases). We did not detect either activating EGFR mutations, nor copy number gains at the EGFR or ERBB2 loci as poor prognostic features for fusion-positive MEC in any of the tumor specimens. Prospective studies with larger case series will be needed to confirm that combined CRTC1-MAML2 and CDKN2A genotyping will optimally stage this disease.

Indication for elective neck dissection for N0 carcinoma of the parotid gland: a single institution's 20-year experience

CONCLUSIONS

Elective neck dissection (END) may not be necessary in patients with low-grade malignancy. However, currently, END should be performed in all patients with parotid carcinoma because the preoperative diagnosis of lymph node metastasis is limited and the accuracy of preoperative grade diagnosis is low.

OBJECTIVE

Our aim was to examine the indication for END in N0 patients and the extent of dissection by investigating the accuracy of diagnosing the grade and lymph node metastasis of parotid carcinoma.

PATIENTS AND METHODS

The subjects were 77 patients with parotid carcinoma. Among N0 patients, modified radical neck dissection (MRND) was conducted in those in whom the histological grade was evaluated as high, and selective neck dissection (SND) in other patients.

RESULTS

Lymph node metastasis was detected in 27 of 71 patients who underwent neck dissection. Node metastasis was detected in 19 (61.3%) of 31 patients in whom high-grade malignancy was suggested and in 8 (22.9%) of 35 patients in whom intermediate-grade malignancy was suggested preoperatively. There was no metastasis in any of the five patients in whom low-grade malignancy was suggested. Occult metastasis was noted in 8 of 51 patients. The rate at which the histological grade was accurately diagnosed before surgery was low, especially in patients with low-grade malignancy.

Treatment and survival outcomes based on histologic grading in patients with head and neck mucoepidermoid carcinoma

BACKGROUND

Histopathologic grade of mucoepidermoid carcinoma (MEC) is an established predictor of prognosis and affects treatment protocol. Tumor behavior is more aggressive in high-grade than in low-grade MEC, leading to a more intensive treatment protocol. Outcomes for patients with intermediate-grade MEC are less clear; therefore, the optimal treatment protocol for this group is not well defined. The treatment protocol and survival outcomes of patients treated for MEC of the head and neck was investigated.

METHODS

A retrospective clinical review and prospective review of histopathologic grading were undertaken using the most recently established grading system of 50 patients with MEC of the head and neck from 1983 through 2004.

RESULTS

As histologic grade increased from low to intermediate to high, overall survival (P < .0001) and disease-free survival (P < .001) were significantly decreased. Overall and disease-free survival were significantly better for patients with intermediate-grade MEC than those with high-grade disease. Overall and disease-free survival were similar for patients with low-grade and intermediate-grade MEC. There was a low rate of disease recurrence in patients with intermediate-grade MEC, but this did not lead to death from disease. Although no patients with low-grade or intermediate-grade MEC died of disease, 52% of patients with high-grade MEC died of disease. Multivariate analysis revealed that histologic grade, age, and surgical margin status significantly predicted prognosis.

CONCLUSIONS

These findings suggest that, under the current histopathologic classification system, the behavior of intermediate-grade MEC is comparable to that of low-grade MEC and different from high-grade MEC, allowing for the establishment of an evidence-based treatment protocol.

Neck masses: evaluation and diagnostic approach

Oral and maxillofacial surgeons frequently deal with patients who present with an unknown neck mass. Formulation of a differential diagnosis is essential and requires that the surgeon bring to bear a host of skills to systematically arrive at a definitive diagnosis and ensure that the correct treatment is rendered. This article highlights some of the skills needed in the workup of neck masses and reviews some of the available techniques that aid in achieving the correct diagnosis.

Mucoepidermoid carcinoma of the head and neck: clinical analysis of 43 patients

OBJECTIVE

It is well known that mucoepidermoid carcinoma (MEC) displays a variety of biological behaviors. While the high-grade type is a highly aggressive tumor, its low-grade counterpart usually demonstrates a more benign nature and several systems have, therefore, been proposed to grade this neoplasm.

METHODS

This report analyzes 43 patients suffering from head and neck MEC, who were treated in our department during the period from 1989 to 2005. The relationship between clinical and pathologic characteristics and survival rate was investigated.

RESULTS

The 5-year overall and disease-free survival rate was 62.3 and 57.2%. Multivariate analysis demonstrated that the parameters that significantly affected survival were the patient's age (P = 0.040) and treatment method (P = 0.011).

CONCLUSIONS

The patient's age and treatment method is the prognostic parameter in this study. Although complete surgical resection is the standard treatment for MEC, we should aggressively consider adjunctive radiotherapy in those cases that have a high risk of recurrence and poor prognosis.

Molecular diagnosis in head and neck: what a surgical pathologist must know

Molecular alterations in tumors have become interesting targets both for diagnostic and for therapeutic and prognostic applications in tumor pathology. In the head and neck, there are a variety of different alterations, encompassing all the different types of genetic events associated with carcinogenesis. This paper reviews three different types of tumors that display a spectrum of genetic alterations: the translocation in Mucoepidermoid carcinoma, Epstein Barr virus association in nasopharyngeal carcinoma, and the HRPT2 tumor suppressor gene in parathyroid carcinoma. Basic histology is reviewed and the genetic alterations are discussed, along with a brief discussion of potential diagnostic implications.

Prognostic factors of tracheobronchial mucoepidermoid carcinoma--15 years experience

BACKGROUND AND OBJECTIVES

Mucoepidermoid carcinoma of the tracheobronchial tree is a rare tumour which displays a variable degree of clinical aggressiveness and malignancy. The relationship between the patient's prognosis and the tumour's histological features and clinical behaviour is uncertain. The aim of this study was to identify the clinicopathological features and analyse the outcomes of patients with this type of cancer.

METHODS

A retrospective analysis of the medical records of patients diagnosed with mucoepidermoid carcinoma of the lung between 1991 and 2006 was conducted.

RESULTS

The study comprised 15 patients. Higher histological grade tumours had a higher proportion of squamoid cells (P = 0.019); the tumours of patients with lymph node metastases also had a higher proportion of squamoid cells than did the tumours of patients without lymph node metastases (P = 0.015). Patients with early stage tumours (stage IA, IB, IIB) had better outcomes (10-year survival rate = 87.5%), than did patients with late-stage tumours (stage IIIB, IV) (1-year survival rate = 28.6%; 2-year survival rate = 0%, P = 0.001). Patients with lower-grade tumours (grade 1 and grade 2) had better outcomes (1-year survival rate = 80%; 5-year survival rate = 57.1%) than did patients with higher-grade tumours (grade 3) (1-year survival rate = 20%, P = 0.035). Tumour staging was a significant independent predictor of survival on Cox proportional hazards analysis.

CONCLUSIONS

The proportion of squamoid cells on tumour histology may be an indicator of the level of tumour malignancy. Tumour, node, metastasis staging is a significant determinant of prognosis in patients with tracheobronchial mucoepidermoid carcinoma.

Pediatric pulmonary tumors: primary and metastatic

Pediatric pulmonary tumors are rare. There is often a significant delay in diagnosis of pulmonary tumors secondary to their rarity and nonspecific presenting physiologic and radiographic findings. A high index of suspicion in pediatric patients with recurrent or persistent pulmonary symptoms is of paramount importance in diagnosing pulmonary tumors at an early stage. Malignant pulmonary tumors are more frequently diagnosed than benign lesions, with metastatic cancers being the most common. Complete surgical resection remains the basis of therapy for primary lesions, and its role in secondary cancers is becoming more established. Adjuvant therapies are frequently employed depending on the precise tumor involved. Mortality rates vary greatly depending on tumor location, stage, and type.

Silencing of CXCR4 inhibits the proliferation, adhesion, chemotaxis and invasion of salivary gland mucoepidermoid carcinoma Mc3 cells in vitro

Mucoepidermoid carcinoma is the most common malignant tumor in salivary glands and high-grade mucoepidermoid carcinoma is often accompanied with poor prognosis. Many recent research works demonstrated that stromal cell-derived factor-1 (SDF-1) and its receptor CXC chemokine receptor-4 (CXCR4) interaction was critical for metastasis of various cancers. In this study, the immunoexpression of CXCR4 in human salivary gland mucoepidermoid carcinoma in different grades was detected by immunohistochemical analysis and the expression of CXCR4 and its ligand SDF-1 in mucoepidermoid carcinoma MEC-1 cell line and its highly metastatic clone Mc3 was examined by RT-PCR, flow cytometry and immunocytochemical analysis. It was found that CXCR4 was over-expressed in Mc3 cell line and SDF-1 was expressed in both cell lines at a nearly equal level. We further constructed CXCR4-shRNA expression vector to stably transfect Mc3 cells. We found that silencing of endogenous CXCR4 gene expression in Mc3 cells resulted in inhibition of the proliferation, adhesion, chemotaxis and invasion of Mc3 cells in vitro. This study implies that CXCR4 molecule is a potential factor controlling the proliferation and metastasis of Mc3 cells.

Prognostic implications of NUMB immunoreactivity in salivary gland carcinomas

The gene numb encodes for a protein (Numb) involved in cell fate decisions in Drosophila, with proposed endocytic and developmental functions in mammalians. The distribution pattern of Numb in human tissues however, has not been fully characterized. We set out to explore the immunohistochemical expression of Numb in normal and neoplastic (28 adenoid cystic and 34 mucoepidermoid carcinomas) salivary glands, and correlated the results with the clinico-pathologic features of the neoplasms. Intense Numb immunoreactivity was detected in normal ductal cells and in a subset of acinar cells. In salivary carcinomas, we detected diffuse and intense Numb immunostaining in 5 adenoid cystic and 8 mucoepidermoid carcinomas. By contrast, the majority of adenoid cystic and mucoepidermoid cancers showed only moderate (14 and 5 cases) or focal staining (9 and 21 cases), respectively. The corresponding expression of Numb mRNA was documented in normal parotid gland and adenoid cystic carcinoma. Numb immunoreactivity was inversely correlated with the histological grade and Ki-67 immunoreactivity of both adenoid cystic and mucoepidermoid carcinomas. In addition, while tumor grade, stage, Ki-67 and Numb immunoreactivity were associated with disease-free survival in univariate analysis, only Numb and Ki-67 immunoreactivities retained independent prognostic significance in multivariate analysis. These data suggest that loss of Numb is implicated in aberrant differentiation programs of salivary gland carcinomas and may serve as a prognostic indicator in patients treated for these neoplasms.

Cytokeratin profile in mucoepidermoid carcinoma is not related to its histological grading of malignancy

The objective of this experiment was to determine the relationship between the expression of cytokeratins (CKs) and histologic grading in MEC. Eleven cases of MEC were selected and graded as low, intermediate and high-grade tumors. The expression of CKs 7, 8, 10, 13 and 14 was assessed immunohistochemically using streptavidin-biotin complex method. The results showed that the studied CKs were expressed in most cases of MEC, independently of histologic grading. Nonetheless, low-grade tumors demonstrated intense staining of CK 7 and 8; additionally, CK 10 and 13 were more pronounced in this grade. The immunoexpression was variable according to cellular type and organization pattern of the tumor. Mucous cells were positive for CK 7 and 8; epidermoid cells were stained for CK 10, 13 and 14; CK 7, 8, 10 and 14 were observed in intermediate cells, and CK 7 was occasionally seen in clear cells. Cystic structures and duct-like elements in MEC were positive for CK 7 and 8, whereas solid nests showed positivity for all CKs. These results suggest that expression profile of these proteins does not reflect the biological behavior of MCE, however, it guides the detection of cellular types and differential diagnosis from other salivary gland tumors.

Mucoepidermoid carcinoma of minor salivary glands: a clinical study of 16 cases and review of the literature

OBJECTIVE

Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of salivary glands with a widely diverse biologic behavior that is correlated with the histological grade of the tumor. The purpose of this study was to evaluate the clinical outcomes of MEC of minor salivary glands in a group of 16 patients, who were treated in our clinic, and to discuss the management of this carcinoma.

MATERIALS AND METHODS

Between 1985 and 2000, 16 patients with MEC of minor salivary glands were treated in the Clinic of Oral and Maxillofacial Surgery of the 'G. Papanikolaou' General Hospital, in Thessaloniki. The age range was 16-65 years. The distribution of the primary sites was: hard plate (one), soft palate (two), hard and soft palate (three), hard and soft palate with spread in paranasal sinus and nasal cavity (one), buccal mucosa (three), hard palate, alveolar process and buccal mucosa (two), and retromolar triangle (our). The tumors were clinically staged according to the tumor nodes metastase (TNM) system (Seifert, 1991). All patients were treated radically with surgery. The surgery was combined with radiotherapy in nine patients. Radiotherapy was delivered using Co-60. Doses ranged from 50 to 60 Gy and the duration of the therapy ranged from 25 to 35 days. Immunohistochemical assay of the expression of the Ki-67 antigen was performed on a subset of 15 cases.

RESULTS

The mean follow-up range was 4-14 years. From the 16 patients with MECs 10 (62.5%) were alive and five (35.6%) had died from the disease. Four patients were free of the disease for more than 5 years (range 8-14), five patients were free of the disease for 5 years and one patient was free of the disease for 4 years. One patient lived more than 10 years and died from another cause. Local recurrence developed in one patient 10 years after the initial treatment. Lymph node metastases occurred in one patient within the first year after the initial surgical treatment. Distant metastases (two in bones and one in lungs) occurred in three patients within 2 years after completing the treatment. The Pearson chi-square statistical analysis was used for comparing the Ki-67 values in correlation with histological grade of the tumors. The Ki-67 expression was only 1% in low-grade MECs, while in intermediate-grade tumors it was estimated between 3 and 4%. The high-grade tumors had increased expression (10%) of tumor cells.

CONCLUSION

Complete surgical excision is the treatment of choice for MECs. Adequate excision is important in all grades of tumors. Prognosis of MECs is a function of the histological grade, adequacy of excision and clinical staging. The immunohistochemical study of Ki-67 expression may provide additional prognostic information for this tumor.

Gene expression screening of salivary gland neoplasms: molecular markers of potential histogenetic and clinical significance

Salivary gland neoplasms comprise phenotypically and biologically diverse lesions of uncertain histogenesis. The molecular events associated with their development and clinicopathological heterogeneity remain unknown. To reveal these events, we performed microarray expression analysis using a nylon-filter membrane platform on 18 primary lesions representing the most common benign and malignant types. Our study identified a small set of genes that are differentially altered between normal salivary gland tissues and benign and malignant tumors. Of the 5000 genes arrayed, 136 genes were differentially expressed by normal tissue, benign tumors, and various malignant neoplasms. Hierarchical clustering analysis differentiated between adenoid cystic carcinomas (ACCs) and other malignant subtypes. Non-ACC specimens manifested overlapping patterns of gene expression within and between tumors. Most of the differentially expressed genes share functional similarities with members of the adhesion, proliferation, and signal transduction pathways. Our study identified: 1) a set of genes that differentiate normal tissue from tumor specimens, 2) genes that differentiate pleomorphic adenoma and ACCs from other malignant salivary gland neoplasms, and 3) different patterns of expression between ACCs arising from major and minor salivary gland sites. The differentially expressed genes provide new information on potential genetic events of biological significance in future studies of salivary gland tumorigenesis.

Radiotherapy alone or combined with surgery for salivary gland carcinoma

BACKGROUND

The authors analyzed the outcomes of patients treated with radiotherapy (RT) alone or combined with surgery for carcinoma of the salivary glands.

METHODS

Between October 1964 and June 2003, 224 previously untreated patients were treated with curative intent with RT alone (n = 64) or combined with surgery (n = 160) at the University of Florida College of Medicine (Gainesville, FL). The median follow-up period was 5.0 years (range, 0.4-31.6 years).

RESULTS

The 10-year local control rate was 75%. Multivariate analysis of local control revealed that T classification (P < 0.0001) and treatment group (P < 0.0001) impacted this end point. Patients treated with surgery and adjuvant RT had improved local control compared with patients treated with RT alone. The 10-year locoregional control rate was 68%. Multivariate analysis of locoregional control revealed that overall stage (P < 0.0001) and treatment group (P = 0.0002) significantly influenced this end point. The 10-year distant metastasis-free survival rate was 68%. Multivariate analysis of distant metastasis-free survival revealed that overall stage (P < 0.0001) significantly influenced this end point. The 10-year cause-specific and overall survival rates were 57% and 44%, respectively. Multivariate analysis of cause-specific survival revealed that overall stage (P < 0.0001) significantly impacted this end point. Twenty-three patients (10%) experienced severe complications.

CONCLUSIONS

A substantial proportion of patients with salivary gland carcinoma were cured with surgery combined with adjuvant RT. RT alone was used for patients with unresectable tumors and cured approximately 20% of those with advanced-stage disease. The probability of cure was influenced by the extent of disease and treatment group.

Mucoepidermoid carcinoma of the salivary glands––clinical review of 42 cases

In this retrospective study we analyzed our experience with mucoepidermoid carcinoma (MEC) of the salivary glands and compared our results with those reported in the literature. A total of 42 patients were treated between January 1983 and December 2002 at the Department of Oral and Maxillofacial Surgery, Hanover Medical School. Thirty-three tumors were classified as low grade carcinomas, 9 tumors as high grade carcinomas. Tumor sites were the parotid gland in 11 cases, sublingual and submandibular gland in 6 cases, oral cavity and oropharynx in 22 cases and nasal cavity and maxillary sinus in 3 cases. There were 23 T1-, 6 T2-, 5 T3- and 8 T4-tumors with 35 N0-, 5 N1- and 2 N2-necks, all M0 at presentation. Resection remained incomplete for 9 patients. Six patients received postoperative radiation. Overall survival rates, overall local control rates and overall regional control rates at 5 and 10 years were 79.1% and 65.5%, 89.1% and 80.8%, 92.3% and 87.7%. None of our patients developed distant failure. Grade, stage and margin status significantly influenced prognosis. MEC is a rare tumor entity and should be treated in specialist centres within randomised prospective multicentric trials.

Epithelial malignancies of the salivary glands: clinical experience of a single institution—a review

In this retrospective study we give a clinical review of our experience with different subtypes of salivary gland cancer. Between January 1983 and December 2002, a total of 155 patients with carcinomas of the salivary glands received initial treatment at the Department of Oral and Maxillofacial Surgery, Hanover Medical School. There were 79 (51.0%) adenoid cystic carcinomas, 42 (27.1%) mucoepidermoid carcinomas, 12 (7.7%) adenocarcinomas, 10 (6.5%) polymorphous adenocarcinomas and 12 (7.7%) other tumor entities of smaller number. Complete resection was reached for 63.5% of patients with high grade carcinomas and for 80.0% of patients with low grade carcinomas. 26.2% of patients with high grade carcinomas and 13.3% of patients with low grade carcinomas received postoperative radiation. Overall survival rates at 5, 10 and 15 years were 65.9, 48.0 and 39.8% with significant difference for patients with high grade and low grade carcinomas. Histopathologic subtype, tumor stage and margin status significantly influenced prognosis. Statistically, we were not able to demonstrate a positive effect for postoperative radiation. In the future, patients with salivary gland carcinomas should be randomised for prospective multicentric clinical trials, which could provide reliable information about adjuvant treatment modalities and their results even for rare subtypes of salivary gland cancer.

[Malignant epithelial salivary gland tumors. Clinical review of 2 decades]

PURPOSE

In this retrospective study we give a clinical review of our experience with different tumor entities of salivary gland cancer.

PATIENTS

Between January 1983 and December 2002, a total of 155 patients with carcinomas of the salivary glands received initial treatment at the Department of Oral and Maxillofacial Surgery, Hanover Medical School.

RESULTS

There were 51.0% adenoid cystic carcinomas, 27.1% mucoepidermoid carcinomas, 7.7% adenocarcinomas, 6.5% polymorphous adenocarcinomas, and altogether 7.7% other less frequent tumor entities. Complete resection was achieved for 63.5% of patients with high-grade carcinomas and for 80.0% of patients with low-grade carcinomas. Postoperative radiation was administered to 26.2% of patients with high-grade carcinomas and 13.3% of patients with low-grade carcinomas. Overall local control rates at 5, 10, and 15 years were 77.5%, 66.2%, and 59.0%. Overall regional control rates at 5, 10, and 15 years were 93.5%, 87.6%, and 85,4%. Overall distant control rates at 5, 10, and 15 years were 85.9%, 77,2%, and 73,6%. Overall survival rates at 5, 10, and 15 years were 65,9%, 48,0%, and 39,8%. There was a significant difference between patients with low-grade and high-grade carcinomas. Polymorphous adenocarcinomas showed the best prognosis, followed by low-grade mucoepidermoid carcinomas, adenoid cystic carcinomas, adenocarcinomas, and high-grade mucoepidermoid carcinomas. The number of the remaining tumor entities was too small to be divided into independent subgroups for statistical analysis. Tumor entity, tumor stage, and margin status significantly influenced prognosis. Statistically, we were not able to demonstrate a positive effect for postoperative radiation.

CONCLUSION

Grading is important, but should be considered in the context of stage. In the future, patients with salivary gland carcinomas should be randomized for prospective multicenter clinical trials, which could provide reliable information about adjuvant treatment modalities and their results even for rare subtypes of salivary gland cancer.

Cadherin and catenin expression in mucoepidermoid carcinoma: correlation with histopathologic grade, clinical stage, and patient outcome

BACKGROUND

Alteration of cadherin and catenin expression is associated with loss of differentiation, acquisition of an invasive phenotype, and poor prognosis in many types of cancers. The roles of cadherins and catenins in mucoepidermoid carcinoma (MEC) are not fully understood.

METHODS

Based on immunohistochemical studies, the expressions of E-, N-, and P-cadherins and alpha-, beta-, and gamma-catenins in MEC were investigated, and correlations with clinicopathologic parameters were evaluated.

RESULTS

These six molecules were strongly expressed in normal ductal epithelium but increased or decreased immunoreactivities of those proteins in MEC were frequently observed, especially for E-cadherin and alpha-catenin. The immunoactivity of beta-catenin showed significant correlation with grade (P = 0.05) and stage (P < 0.0001). beta-Catenin expressions are also correlated with gamma-catenin expression (P = 0.006) according to cross-table analysis. Survival analysis indicated that stage, grade, and beta-catenin expressions had significant correlation with survival.

CONCLUSION

Aberrant beta-catenin expression may play an important role in the histologic differentiation and tumor staging of MEC.

Primary high-grade mucoepidermoid carcinoma of the minor salivary glands with cutaneous metastases at diagnosis

Mucoepidermoid carcinoma (MEC) represents 15% of all salivary glands malignancies. Metastatic disease at diagnosis is observed in less than 5% of the cases. The lung is the most commonly involved site. This is the first reported case of high-grade MEC of the salivary gland with skin metastases at diagnosis. This feature was associated with a chemoresistant and aggressive behaviour. Differential diagnosis between metastatic MEC and primary skin MEC is essential for therapeutic management and prognosis.

Parotid gland mucoepidermoid carcinoma in a 4-year-old child

Salivary gland tumors account for less than 5% of the head and neck neoplasms. Among them, mucoepidermoid carcinoma is the most common malignant salivary gland tumor. About 45% of mucoepidermoid carcinomas occur in the parotid gland, and appear around the fifth decade of life, being unusual in children under 10 years. We report a case of a parotid mass arising in a 4-year-old female, who had no lateral adenopathy. After histological examination, the diagnosis was of a low-grade mucoepidermoid carcinoma of the parotid gland. Three years after surgery no recurrence was observed. As a conclusion, although rare, the presence of a parotid mass with progressive growth in children could correspond to a neoplasm.

A Case of Parotid Mucoepidermoid Carcinoma Complicated by Fatal Gastrointestinal Bleeding

Mucoepidermoid carcinoma is one of the most common of the salivary gland neoplasms. Histologically, it is classified as either a low-, intermediate-, or high-grade tumor, and there are significant differences in prognosis among the different grades. Patients with low-grade disease have an excellent chance of survival. High-grade tumors behave aggressively, and they frequently manifest as local recurrences and distant metastases. We describe a case of a high-grade mucoepidermoid carcinoma of the parotid gland that had metastasized to the skin, stomach, and liver. The disease culminated in a rapidly fatal bleeding from the stomach metastasis. Such a complication is unusual and to our knowledge has not been previously reported. We briefly discuss the clinical features, biologic behavior, and treatment of this tumor.

Mucoepidermoid carcinoma: a clinicopathologic study of 80 patients with special reference to histological grading

We sought to review our experience with salivary mucoepidermoid carcinoma (MEC) over two decades to confirm the validity and reproducibility of histologic grading and to investigate MIB-1 index as a prognosticator. Diagnosis was confirmed on 80 cases, and chart review or patient contact was achieved for 48 patients, with follow-up from 5 to 240 months (median 36 months). Immunohistochemistry with citrate antigen retrieval for MIB-1 was performed on a subset of cases. Kaplan-Meier survival curves were generated for each stage, site, and grade according to our proposed grading system. To address the issue of grading reproducibility, 20 slides were circulated among five observers, without prior discussion; slides were categorized as low-, intermediate-, or high-grade according to one's "own" criteria, and then according to the AFIP criteria proposed by Goode et al.10 Weighted kappa (kappa) estimates were obtained to describe the extent of agreement between pairs of rating. The Wilcoxon signed rank test or the Friedman test as appropriate tested variation across ratings. There was no gender predominance and a wide age range (15-86 years, median 49 years). The two most common sites were parotid and palate. All grade 1 MECs presented as Stage I tumors, and no failures were seen for this category. The local disease failure rates at 75 months for grades 2 and 3 MEC were 30% and 70%, respectively. Tumor grade, stage, and negative margin status all correlated with disease-free survival (DFS) (p = 0.0091, 0.0002, and 0.048, respectively). The MIB index was not found to be predictive of grade. Regarding the reproducibility of grading, the interobserver variation for pathologists using their "own" grading, as expressed by the kappa value, ranged from good agreement (kappa = 0.79) to poor (kappa = 0.27) (average kappa = 0.49). A somewhat better interobserver reproducibility was achieved when the pathologists utilized the standardized AFIP criteria (average kappa = 0.61, range 0.38-0.77). This greater agreement was also reflected in the Friedman test (statistical testing of intraobserver equality), which indicated significant differences in using one's own grading systems (p = 0.0001) but not in applying the AFIP "standardized" grading (p = 0.33). When one's own grading was compared with the AFIP grading, there were 100 pairs of grading "events," with 46 disagreements/100 pairs. For 98% of disagreements, the AFIP grading "downgraded" tumors. This led us to reanalyze a subset of 31 patients for DFS versus grade, for our grading schema compared with the AFIP grading. Although statistical significance was not achieved for this subset, the log rank value revealed a trend for our grading (p = 0.0993) compared with the Goode schema (p = 0.2493). This clinicopathologic analysis confirms the predictive value of tumor staging and three-tiered histologic grading. Our grading exercise confirms that there is significant grading disparity for MEC, even among experienced ENT/oral pathologists. The improved reproducibility obtained when the weighted AFIP criteria were used speaks to the need for an accepted and easily reproducible system. However, these proposed criteria have a tendency to downgrade MEC. Therefore, the addition of other criteria (such as vascular invasion, pattern of tumor infiltration [i.e., small islands and individual cells vs cohesive islands]) is necessary. We propose a modified grading schema, which enhances predictability and provides much needed reproducibility.

Mucoepidermoid carcinoma of salivary glands in children and adolescents: assessment of proliferation markers

Malignant neoplasms represent one-third of all pediatric salivary gland tumors. Mucoepidermoid carcinoma (MEC) composes 51% of malignant tumors and 16% of all salivary gland neoplasms in pediatrics. Prognostic factors in MEC in pediatric patients have not been well defined. Histopathologic features, clinical outcomes and proliferation markers in 26 pediatric patients (median age 11 years; 19F:7M) with salivary gland MECs were evaluated retrospectively. MEC histocytologic grading used a three-tiered system. Proliferation was assessed by determining the percentage of tumor cells immunoreactive for PCNA and Ki-67. Tumor site was 16 parotid, eight submandibular, one base of tongue and one maxillary lip. Median tumor size was 2.5 cm (range 1.5-5 cm). MEC grade was nine low grade (LG), 15 intermediate grade (IG) and two high grade (HG). Metastatic disease and capsular invasion occurred in five cases, while perineural invasion was noted in three cases. Mean percentage of tumor cells immunoreactive for proliferation markers is as follows: PCNA: LG 9%, IG 17%, HG 32%; and Ki-67: LG 7%, IG 12%, HG 26%. Treatment was surgical in 21 cases, and surgery with chemotherapy and radiotherapy in five cases. Two patients with high grade MECs died of disease (21, 44 months). Twenty-four patients had no evidence of disease at a median follow-up of 104 months (range 30-298 months). MECs were second malignancies in two children with prior radiotherapy and chemotherapy for leukemia and histiocytosis. Low and intermediate grade salivary gland MECS in a pediatric population may have a favorable outcome when compared with high grade MECs. Proliferation markers appear to be linked to histocytologic MEC grade and may provide information regarding biologic behavior of salivary gland MECs in children and adolescents.

Proliferating cell nuclear antigen expression in mucoepidermoid carcinoma of salivary glands

CONTEXT

Among the cytological and morphological properties of mucoepidermoid carcinoma, one of the most important criteria for measuring its biological behavior and aggressiveness is cell proliferation. In this way, immunohistochemical markers of cell proliferation have been found to be useful in tumor classification and have formed part of the prognostic and therapeutic studies of these pathologies.

OBJECTIVE

To analyze 11 cases of mucoepidermoid carcinoma (MEC) using the proliferation activity marker (PCNA) and to determine its relationship to the grade of malignancy of these tumors.

DESIGN

Correlation study.

SETTING

Head and Neck Surgery Service of Heliópolis Hospital, São Paulo, Brazil.

SAMPLE

Slides of 11 cases of primary mucoepidermoid carcinomas of salivary glands were prepared according to routine techniques employed in the Oral Pathology Department of the Dentistry Faculty of São Paulo University, Brazil. They were fixed in a 10% formaldehyde solution and stained with hematoxylin and eosin. After this preparation the tumors were classified as low, intermediate and high grade of malignancy, according to the criteria established by Seifert & Sobin and Auclair, Goode & Ellis. The slides were sent for immunohistochemical processing to evaluate the positivity of proliferating cell nuclear antigen using the streptavidin biotin technique.

MAIN MEASUREMENT

The correlation between proliferating cell nuclear antigen expression and the histological malignancy grade in mucoepidermoid carcinoma of salivary glands.

RESULTS

there were 4 cases (36%) of low grade, 4 cases (36%) of intermediate grade and 3 cases (27%) of high grade of malignancy. After a comparative study between histological features and immunohistochemical analysis, significant differences were observed (P < 0.01) for low, intermediate and high grades: 16.04%, 26.98% and 56.98% of proliferating cell nuclear antigen expression in mucoepidermoid carcinoma, respectively.

CONCLUSION

The proliferating cell nuclear antigen expression increases with the grade of malignancy in mucoepidermoid carcinoma of salivary glands.