Salivary Gland Pleomorphic Adenoma

TGFβ signaling pathway in salivary gland tumors

OBJECTIVE

Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are the most prevalent salivary gland tumors. Their pathogenesis has been recently associated with complex molecular cascades, including the TGFβ signaling pathway. The aim of this study was to evaluate the expression of genes associated with the TGFβ signaling pathway (TGFB1, ITGB6, SMAD2, SMAD4, FBN1, LTBP1, and c-MYC) to map possible downstream alterations in the TGFβ cascade.

DESIGN

Thirteen PA, 17 MEC, 13 ACC, and 10 non-neoplastic salivary gland samples were analyzed by real-time RT-PCR.

RESULTS

Cases of PA presented increased TGFB1, LTPB1, c-MYC, and FBN1 expressions, whereas SMAD2 expression was decreased when compared to non-neoplastic tissue. MEC patients displayed increased expressions of TGFB1, ITGB6, FBN1, and c-MYC and decreased expressions of SMAD2 and SMAD4. ACC cases exhibited elevated expressions of the investigated genes except TGFB1. The present results suggest that decreased expression of SMAD2 and SMAD4 does not impede the transcriptional regulation of c-MYC, especially in PA and MEC. Increased expressions of ITGB6, TGFB1, LTBP1, and FBN1 appear to be related to the regulation of the TGFβ signaling pathway in these tumors. Additionally, we observed a higher expression of SMAD4 in ACC and a raised expression of ITGB6 and lowered expression of SMAD2 in MEC.

CONCLUSIONS

Our study demonstrated the differential expression of TGFβ cascade members in salivary gland tumors such as SMAD2/SMAD4 and c-MYC as well as the participation of ITGB6, TGFB1, LTBP1, and FBN1, contributing to the understanding of the mechanisms involved in tumor progression.

The Great Imposter: An Atypical Case of Pleomorphic Adenoma With Review of Literature

Pleomorphic adenomas (PA) are the most common type of salivary gland tumors. These slow-growing benign tumors most commonly involve the parotid gland, but can sometimes occur at atypical sites such as the submandibular or minor salivary glands. We describe an atypical case of pleomorphic adenoma with multicentric involvement of the parotid, the submandibular gland, and the parapharyngeal space in a 35-year-old male which mimicked a slow-flow malformation on magnetic resonance imaging (MRI). Diagnosis was confirmed on fine needle aspiration cytology, and conservative approach was opted for the patient in view of perioperative risks. This case highlights the uncommon multicentricity and atypical presentation of PA, challenging the initial differential diagnosis based on MRI features. It also underscores the importance of considering atypical presentations and utilizing accurate diagnostic tools like cytology for managing complex salivary gland tumors.

Salivary gland pathologies: evolution in classification and association with unique genetic alterations

PURPOSE

The correct classification of salivary gland pathologies is crucial for choosing a treatment method and determining the prognosis. Better outcomes are now achievable thanks to the introduction of new therapy approaches, such as targeted therapies for malignant salivary gland tumors. To apply these in clinical routine, a clear classification of the lesions is required.

METHODS

The following review examines all changes from the first World Health Organization (WHO) Classification of salivary gland pathologies from 1972 to fifth edition from 2022. Possible developments in the diagnosis and classification of salivary gland pathology are also presented.

RESULTS

The current WHO classification is the fifth edition. With the development of new diagnostic methods, based on genetic alterations, it provides insight into the molecular basis of lesions. This has resulted in the evolution of classification, introduction of new entities and reclassification of existing ones.

CONCLUSIONS

Genetic alterations will become increasingly more significant in the identification of salivary gland pathologies in the future. These alterations will be helpful as prognostic and predictive biomarkers, and may also serve as targets for anti-cancer therapies.

Differentiation between pleomorphic adenoma and schwannoma in the parapharyngeal space: histogram analysis of apparent diffusion coefficient

OBJECTIVES

To elucidate the differences between pleomorphic adenomas and schwannomas occurring in the parapharyngeal space by histogram analyses of apparent diffusion coefficient (ADC) values measured with diffusion-weighted MRI.

METHODS

This retrospective study included 29 patients with pleomorphic adenoma and 22 patients with schwannoma arising in the parapharyngeal space or extending into the parapharyngeal space from the parotid region. Using pre-operative MR images, ADC values of tumor lesions showing the maximum diameter were measured. The regions of interest for ADC measurement were placed by contouring the tumor margin, and the histogram metrics of ADC values were compared between pleomorphic adenomas and schwannomas regarding the mean, skewness, and kurtosis by Wilcoxon's rank sum test. Subsequent to the primary analysis which included all lesions, we performed two subgroup analyses regarding b-values and magnetic field strength used for MRI.

RESULTS

The mean ADC values did not show significant differences between pleomorphic adenomas and schwannomas for the primary and subgroup analyses. Schwannomas showed higher skewness (p = 0.0001) and lower kurtosis (p = 0.003) of ADC histograms compared with pleomorphic adenomas in the primary analysis. Skewness was significantly higher in schwannomas in all the subgroup analyses. Kurtosis was consistently lower in schwannomas but did not reach statistical significance in one subgroup analysis.

CONCLUSIONS

Skewness and kurtosis showed significant differences between pleomorphic adenomas and schwannomas occupying the parapharyngeal space, but the mean ADC values did not. Our results suggest that the skewness and kurtosis of ADC histograms may be useful in differentiating these two parapharyngeal tumors.

Pleomorphic Adenoma of a Minor Salivary Gland of the Hard Palate: A Case Report

Pleomorphic adenoma affects mostly the parotid gland (85%), submandibular glands (5%), and the minor salivary glands (5%). They are usually referred to as benign mixed tumors because they are composed of both epithelial cells, which are cells from the body's surface, and myoepithelial cells, present inside glands to aid in secretion. An 88-year-old male who had an ulcer for 10 days and a three to four-month-old swelling on his palate arrived in the OPD. On examination, at the intersection of the hard and soft palates, there is a single, well-delineated, nodular exophytic development of small salivary glands left to the median half (most of the pleomorphic adenomas are unilateral). For further and confirmatory diagnosis, fine needle aspiration cytology, immunohistochemistry tests, and radiodiagnosis, i.e., X-rays, were performed which revealed periapical abscess and swelling on palate unassociated with pus discharge. Surgical removal of the swelling and extraction of the root stump was done. The patient was asked to stop smoking strictly. Post-operatively, the patient was given suitable medications.

Single-cell transcriptomic analysis uncovers the origin and intratumoral heterogeneity of parotid pleomorphic adenoma

Pleomorphic adenoma (PA) is the most common benign tumour in the salivary gland and has high morphological complexity. However, the origin and intratumoral heterogeneity of PA are largely unknown. Here, we constructed a comprehensive atlas of PA at single-cell resolution and showed that PA exhibited five tumour subpopulations, three recapitulating the epithelial states of the normal parotid gland, and two PA-specific epithelial cell (PASE) populations unique to tumours. Then, six subgroups of PASE cells were identified, which varied in epithelium, bone, immune, metabolism, stemness and cell cycle signatures. Moreover, we revealed that CD36+ myoepithelial cells were the tumour-initiating cells (TICs) in PA, and were dominated by the PI3K-AKT pathway. Targeting the PI3K-AKT pathway significantly inhibited CD36+ myoepithelial cell-derived tumour spheres and the growth of PA organoids. Our results provide new insights into the diversity and origin of PA, offering an important clinical implication for targeting the PI3K-AKT signalling pathway in PA treatment.

Extracellular matrix remodelling and stiffening contributes to tumorigenesis of salivary carcinoma ex pleomorphic adenoma--A study based on patient-derived organoids

BACKGROUND

Salivary carcinoma ex pleomorphic adenoma (CXPA) is defined as a carcinoma that develops from benign pleomorphic adenoma (PA). Abnormally activated Androgen signaling pathway and amplification of HER-2/neu(ERBB-2) gene are known to be involved in CXPA tumorigenesis. Recent progress in tumour microenvironment research has led to identification that extracellular matrix (ECM) remodelling and increased stiffness act as critical contributing role in tumour carcinogenesis. This study examined ECM modifications to elucidate the mechanism underlying CXPA tumorigenesis.

RESULTS

PA and CXPA organoids were successfully established. Histological observation, immunohistochemistry (IHC), and whole-exome sequencing demonstrated that organoids recapitulated phenotypic and molecular characteristics of their parental tumours. RNA-sequencing and bioinformatic analysis of organoids showed that differentially expressed genes are highly enriched in ECM-associated terms, implying that ECM alternations may be involved in carcinogenesis. Microscopical examination for surgical samples revealed that excessive hyalinized tissues were deposited in tumour during CXPA tumorigenesis. Transmission electron microscopy confirmed that these hyalinized tissues were tumour ECM in nature. Subsequently, examination by picrosirius red staining, liquid chromatography with tandem mass spectrometry, and cross-linking analysis indicated that tumour ECM was predominantly composed of type I collagen fibers, with dense collagen alignment and an increased level of collagen cross-linking. IHC revealed the overexpression of COL1A1 protein and collagen-synthesis-related genes, DCN and IGFBP5 (p < 0.05). Higher stiffness of CXPA than PA was demonstrated by atomic force microscopy and elastic imaging analysis. We utilized hydrogels to mimic ECM with varying stiffness degrees in vitro. Compared with softer matrices (5Kpa), CXPA cell line and PA primary cells exhibited more proliferative and invasive phenotypes in stiffer matrices (50Kpa, p < 0.01). Protein-protein interaction (PPI) analysis of RNA-sequencing data revealed that AR and ERBB-2 expression was associated with TWIST1. Moreover, surgical specimens demonstrated a higher TWIST1 expression in CXPA over PA. After knocking down TWIST1 in CXPA cells, cell proliferation, migration, and invasiveness were significantly inhibited (p < 0.01).

CONCLUSION

Developing CXPA organoids provides a useful model for cancer biology research and drug screening. ECM remodelling, attributed to overproduction of collagen, alternation of collagen alignment, and increased cross-linking, leads to increased ECM stiffness. ECM modification is an important contributor in CXPA tumorigenesis.

An anatomy-aware framework for automatic segmentation of parotid tumor from multimodal MRI

Magnetic Resonance Imaging (MRI) plays an important role in diagnosing the parotid tumor, where accurate segmentation of tumors is highly desired for determining appropriate treatment plans and avoiding unnecessary surgery. However, the task remains nontrivial and challenging due to ambiguous boundaries and various sizes of the tumor, as well as the presence of a large number of anatomical structures around the parotid gland that are similar to the tumor. To overcome these problems, we propose a novel anatomy-aware framework for automatic segmentation of parotid tumors from multimodal MRI. First, a Transformer-based multimodal fusion network PT-Net is proposed in this paper. The encoder of PT-Net extracts and fuses contextual information from three modalities of MRI from coarse to fine, to obtain cross-modality and multi-scale tumor information. The decoder stacks the feature maps of different modalities and calibrates the multimodal information using the channel attention mechanism. Second, considering that the segmentation model is prone to be disturbed by similar anatomical structures and make wrong predictions, we design anatomy-aware loss. By calculating the distance between the activation regions of the prediction segmentation and the ground truth, our loss function forces the model to distinguish similar anatomical structures with the tumor and make correct predictions. Extensive experiments with MRI scans of the parotid tumor showed that our PT-Net achieved higher segmentation accuracy than existing networks. The anatomy-aware loss outperformed state-of-the-art loss functions for parotid tumor segmentation. Our framework can potentially improve the quality of preoperative diagnosis and surgery planning of parotid tumors.

Stereotactic radiosurgery for recurrent pleomorphic adenoma of the lacrimal gland: a case report

Lacrimal gland pleomorphic adenomas (LGPAs) are common, benign, and intraorbital tumours that cause exophthalmos, ptosis, and visual disturbances. The curative treatment for LGPAs is gross total resection, and radiotherapy is considered adjunctive for recurrence or an alternative for inoperable LGPAs. Stereotactic radiosurgery (SRS) can be used for precise delivery of high radiation doses to the tumour, crucial in the treatment of intra-and extracranial neoplasms. Here, we present a 95-year-old woman who had a rapidly growing, recurrent LGPA and was successfully treated with SRS. The tumour was controlled without any adverse events over 21 months following SRS. SRS is a potential alternative treatment for recurrent LGPA.

Tight junction gene expression in salivary gland tumors

Salivary gland neoplasms comprise a heterogeneous group of lesions with multiple histological subtypes, each with distinct growth patterns, resulting in a spectrum of tumor-specific prognoses; pleomorphic adenoma (PA) and mucoepidermoid carcinoma (MEC) are the most common representatives of these neoplasms. Many studies have associated specific profiles of membrane and adhesion molecules in salivary gland tissues; these profiles appear to be relevant in tumor biology as well as be interpreted as fingerprints for tumor classification, diagnostic prognostic and therapeutic targets. One of these membrane molecule complexes are the tight junctions, composed by various proteins, in which claudins are protagonists. The aim of this study was to evaluate the expressions of genes that encode tight junction proteins (CLDN-1, -3, -4, -5, -7, and -11, occludin [OCLN], zonula occludens [TJP1, TJP2, and TJP3] and junctional adhesion molecule A [F11R]) in MEC and PA using real time RT-PCR. We observed high expression of CLDN-1 and -7 and low expression of CLDN-3, -11 and TJP2 in MEC compared to PA. PA samples demonstrated high OCLN expression when compared to MEC. CRTC1::MAML2 fusion was detected in 12 of 20 (60.0%) MEC samples and was associated with CLDN7 expression, while the absence of fusion was associated with high histological grade. Increased CLDN5 expression was associated with submandibular gland tumors. This study demonstrated differential expressions of genes encoding tight junction constituent proteins and their associations with tumor characteristics, suggesting their potential future role as diagnostic and prognostic markers.

Giant Pleomorphic Adenomas of Parotid Gland: a Case Series

The parotid gland is the largest salivary gland in the body. Pleomorphic adenomas (PA) are most common benign tumors of parotid gland. If left untreated, they can gradually attain the size which can weigh several kilograms. This paper highlights a case series of 15 cases diagnosed as giant pleomorphic adenoma arising in the parotid gland along with their management. A hospital based, observational study of 15 patients of PA of the parotid gland, > 10 cm in its widest dimension considered as giant, done at tertiary care ENT hospital over period of 9 years. The age of the patients ranged from 30 to 81 years with mean age 50.33 ± 15.30 years. There were 5(33.33%) males and 10(66.67%) females. The time duration of having tumor ranged from 5 to 20 years with mean duration of 10.4 ± 4.17 years and the largest tumor was 25 cm in its largest diameter. Mean weight of tumors was 2.72 ± 0.52 kg. One out of fifteen cases was detected as malignant in nature. All cases were treated by surgical excision without any complications. Pleomorphic adenoma of parotid gland can assume a giant proportion when timely surgical intervention is not done. We can build up confidence and hope for life in patients after complete surgical excision of giant PA.

Novel Technique for the Surgical Management of Pleomorphic Adenoma of the Upper Lip

Pleomorphic adenoma (PA) is one of the most common benign lesions of the salivary glands, with a majority of them occurring in the parotid gland. PA has origin from the epithelial and mesenchymal elements and can arise from both major and minor salivary glands. Among minor salivary glands, the palate is the most commonly affected site, followed by lips, cheeks, gingiva, the floor of the mouth, and tongue. PA of the upper lip without intraoral mucosal involvement is a rare entity. In this article, we report a case of PA of the upper lip in a middle-aged female patient and its surgical management with a novel technique. During six months’ postoperative review, the patient showed excellent wound healing with very minimal scar formation.

SLUG is a key regulator of epithelial-mesenchymal transition in pleomorphic adenoma

The histogenesis of pleomorphic adenoma (PA) of the salivary glands remains controversial. PAs are characterized by the transition of epithelial cells to spindled mesenchymal cells, known as epithelial-mesenchymal transition (EMT). The present study aimed to identify a major EMT-inducing transcription factor (EMT-TF) in PAs. Real-time PCR analysis of SNAIL, SLUG, ZEB1, and TWIST1 demonstrated that only SLUG was significantly upregulated in normal salivary glands and PAs. Combined in situ hybridization for SLUG and multiplex immunohistochemistry for CK19 and P63 revealed that SLUG was specifically expressed in the myoepithelial cells of normal salivary glands. In PAs, SLUG was expressed in neoplastic myoepithelial cells and stromal cells but not in the luminal cells lining the inner layers of tumor glands. SLUG expression showed no correlation with PLAG1 expression, and in vitro experiments demonstrated that PLAG1 suppression in primary cultured PA cells or PLAG1 overexpression in HEK 293 T cells did not affect SLUG levels, indicating that PLAG1 was not involved in the upregulation of SLUG in PAs. The suppression of SLUG expression in cultured PA cells resulted in a morphology change to a less elongated shape and attenuated tumor growth. In addition, SLUG downregulation led to increased E-cadherin and decreased N-cadherin and vimentin expression levels along with decreased migratory activity in cultured PA cells. These findings suggest that SLUG is a major TF that can induce EMT in PAs. In summary, SLUG is specifically and highly expressed in the myoepithelial cells and stromal cells of PAs and is a key regulator of EMT in PAs.

Repair of a postaural fistula with a suprafascial radial forearm free flap

We describe the case of a patient with the rare complication of a chronic postaural fistula following repeated and extensive surgery and adjuvant radiotherapy to the head and neck for a pleomorphic adenoma of the parotid gland. This case demonstrates the importance and value of thorough preoperative planning for major head and neck reconstruction, particularly if the area for reconstruction has distorted anatomy due to prior treatment or damage. In complex free flap reconstruction, it is important to investigate the recipient site with the help of arteriography and give due consideration to the donor site and its postoperative management. We highlight the importance of multidisciplinary work for the care of these patients not only intraoperatively, but also in the preoperative planning stage, and perhaps most importantly in the postoperative care.

EMT in salivary gland tumors: the expression of microRNAs miR-155 and miR-200c is associated with clinical-pathological parameters

BACKGROUND

Epithelial to mesenchymal transition promotes cell adhesion loss, enabling invasion and metastasis. MicroRNAs are a class of small non-codifying RNAs that regulate gene expression.

OBJECTIVES

The aim of this study was to evaluate the expression of microRNAs that could regulate the expression of EMT factors in salivary gland tumors (SGTs).

METHODS AND RESULTS

The expression of microRNAs miR-9, miR-34a, miR-101, miR-138, miR-155, and miR-200c-described in the literature to target EMT factors-was evaluated by Real-time RT-PCR (qPCR) in pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) samples. Bioinformatics tools were applied to identify miR targets and immunohistochemistry was used to examine the expression of the proteins E-cadherin, Twist, ZEB-1, β-Catenin, and c-Kit. Comparing miR expression among SGT types, we observed increased expression of miR-9, and miR-138 in PAs, and increased miR-155 expression in MECs. Low-grade MECs exhibited increased miR-155 expression (p = 0.032). MECs that generated lymph node metastases had increased miR-200c levels (p = 0.018). MECs tended to have decreased expression of EMT-related proteins when compared to the other SGT types (c-Kit p < 0.001, Twist p = 0.014, and ZEB p = 0.012). Notably, increased c-Kit expression was associated with the presence of perineural infiltration in ACC (p = 0.050).

CONCLUSIONS

This study provides evidence of alterations in the expression of EMT-factors regulating miRs, especially of miR-9, miR-138, miR-155, and miR-200c. No significant relationships were found between the expression of these miRs and proteins associated with EMT in SGTs.

An institutional review of recurrent pleomorphic adenoma of the parotid gland

OBJECTIVE

Surgical resection is standard treatment for pleomorphic adenoma (PA) of the parotid gland. A small number (2-5%) of these tumors recur. Recurrence usually necessitates reoperation, which is technically challenging and puts the facial nerve (FN) at risk. The aim of this study is to characterize the recurrent parotid PA population and compare outcomes after surgery for singly recurrent and multiply recurrent tumors.

METHODS

This study was a retrospective chart review of patients at a single tertiary care academic medical center who underwent operations for recurrent PA of the parotid gland between 2007 and 2020. Demographic data, details of surgical interventions, pre- and postoperative FN function, and recurrence rates were studied. These factors were compared between patients with singly and multiply recurrent tumors.

RESULTS

Thirty-eight patients met criteria: 4 patients presented for primary PA and subsequently recurred, 26 with a first recurrence, 7 with a second recurrence, and 1 with a fourth recurrence. Multiply recurrent PAs were more likely to require at least partial nerve sacrifice at the time of reoperation (P = 0.0092). Significantly worse long-term FN outcomes were seen following surgery for multiply recurrent PA (P = 0.008). There was no significant difference between the rate of re-recurrence following first revision surgery vs second-fourth revision surgery. Time to reoperation was significantly shorter between the first and second revision surgery than between the primary surgery and first revision (P = 0.0017).

CONCLUSION

Surgery for recurrent PA incurs high risk to the FN, and this risk appears to increase in the setting of multiple recurrences.

Surgical Treatment of a Giant Pleomorphic Adenoma of the Submandibular Gland: A Case Report

Pleomorphic adenomas (PAs) are the most common benign salivary neoplasms. PAs are generally slow-growing but may sometimes become aggressive and grow rapidly within a short period of time. Here, we report the case of an 83-year-old Chinese woman with an anterior neck mass that had been growing over the past 30 years. She felt uncomfortable because the mass had grown quite rapidly in the past year. The final diagnosis of a PA of the left submandibular gland was confirmed by histopathological and immunohistochemical examinations after surgical resection. Our patient recalled a history of an excision of a neck mass 40 years prior to presentation at another hospital. Based on our imaging findings and surgical findings, we speculate that the neck mass 40 years prior may also have been a PA. Our case reminds us the rare recurrence possibility of PAs, and early and thorough resection may have a good prognosis. In addition, to the best of our knowledge, this is the largest PA of the submandibular gland reported to date.

Pleomorphic adenoma: Detection of PLAG1 rearrangement-positive tumor components using whole-slide fluorescence in situ hybridization

AIM

Pleomorphic adenoma (PA) consists of heterogeneous histological architecture mixed with epithelioid and mesenchymal forms. Various types of epithelial or myoepithelial malignancies arise from PA, but sarcomas are extremely rare. A HUMARA clonality assay has suggested that PA is clonal in nature. However, clonality of various tumor components of PA would be difficult to determine with this assay. In addition, the results obtained should be carefully interpreted. PLAG1 rearrangements are considered a good molecular marker for neoplasticity in PA. We aimed to clarify the neoplasticity of the various tumor components present in PA using whole-slide fluorescence in situ hybridization (FISH).

METHODS

Five PA cases positive for PLAG1 rearrangements were examined. Using an immunohistochemistry panel, cell components in PA were classified into eight cell types. To precisely localize PLAG1 rearrangement-positive cell components at the cellular level, sequential retrieval of whole-slide imaging (WSI) data of HE histology and FISH for PLAG1 rearrangement was carried out.

RESULTS

PLAG1 rearrangements were detected in ductal cells, myoepithelial spindle cells, myoepithelial oncocytic cells, myoepithelial plasmacytoid cells, and mesenchymal chondroid cells, but not in mesenchymal lipid cells, mesenchymal fibrous cells, or vascular endothelial cells. Immunohistochemical PLAG1 expression was restricted to cell components harboring PLAG1 rearrangements.

CONCLUSIONS

The results of the present study indicate that ductal and myoepithelial, chondroid cells are neoplastic but lipid, fibrous, and endothelial cells are not. PLAG1 immunohistochemistry is useful in discriminating neoplastic from non-neoplastic cell components. These findings may be important for elucidating tumorigenesis and the process of malignant transformation in PA.

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.

[The influence of the capsular defect as a risk factor for recurrence in pleomorphic adenoma]

OBJECTIVE

 Aim of this study was to enlighten various aspects of the capsular defect of a pleomorphic adenoma and to analyze its influence on recurrence rate with the help of our data and the relevant literature.

MATERIAL AND METHODS

 The clinical records and histopathological findings of all patients who underwent parotidectomy for pleomorphic adenoma between 2006 and 2020 were evaluated retrospectively. The histological slides of all tumours were critically re-evaluated for this study by an experienced head and neck pathologist. The records of the cases with a capsular defect were examined for information on age, gender, type of surgery and surgical outcome.

RESULTS

 A total of 845 patients were included in the primary group. 7 (0.8 %) recurrences were detected, all of these were resected without a capsular rupture. Positive margins were found in 37 cases (4.4 %). In 13/37 cases the capsular defect was detected intraoperatively, whereas the defect was only identified histopathologically in 24 of the 37 cases. In the group of the intraoperative capsular opening, with a median follow-up of 62 months, the sonographic examination suspected a unilocular recurrence of the pleomorphic adenoma in two cases.

CONCLUSION

 The intraoperative capsule opening does not inevitably seem to lead to a pre-programmed recurrence.

[A complex approach to the differential diagnosis of chronic parenchymal parotitis in children]

BACKGROUND

Chronic parenchymal parotitis is the most common salivary gland disease in children which occurs in about 85% cases. Diagnosis errors in chronic parenchymal parotitis are frequent and important but represent an underemphasized and understudied area of patient safety.

OBJECTIVE

The objective of this study was to elaborate the most effective and acceptable strategies for the diagnosis of chronic parenchymal parotitis in children.

MATERIAL AND METHODS

We studied the histories of 211 patients with a primary diagnosis of chronic parenchymal parotitis. All patients underwent ultrasound diagnostic, as well as medical and genetic counseling and examination of 1st degree relatives and probands.

RESULTS

After additional examinations, 100 children were given other diagnoses. Having analyzed the results of medical-genetic and echographic examinations of 111 patients with chronic parenchymal parotitis and their family members, we have developed a pattern of chronic parenchymal parotitis inheritance. All patients were divided into 3 groups according to the type of inheritance: monogenic inheritance, multifactorial inheritance, and sporadic cases.

CONCLUSION

A complex approach to the differential diagnosis of chronic parenchymal parotitis is what is needed to reduce the frequency of diagnostic errors.

Determining the number and distribution of intraparotid lymph nodes according to parotidectomy classification of European Salivary Gland Society: Cadaveric study

BACKGROUND

To investigate the distribution of the parotid gland's intraglandular lymph nodes using the parotidectomy zones determined by the parotidectomy classification of the European Salivary Gland Society (ESGS).

MATERIALS AND METHODS

A total of 128 parotid glands were dissected from 64 fresh cadavers, by bilateral parotidectomy without additional incision within the standard autopsy procedure, and categorized.

RESULTS

Eighty-six percent of the IGLNs were located in the superficial lobe and 14% in the deep lobe. An average of 7.09 ± 3.55 IGLNs were found for each of the gland; there were 6.11 ± 3.28 in the superficial lobe and 0.98 ± 1.46 in the deep lobe. While the most common lymph nodes were found in level 2 with 47.7%, only 5% of IGLNs were at level 4. According to the proposed modification, the most common lymph nodes (35.24%) were located at level 2B.

CONCLUSION

Level 2B was found to contain significantly more lymph nodes than other levels, which has not been evaluated before in literature.

Reducing the morbidity of parotidectomy for benign pathology

BACKGROUND

Conservative surgical approaches, reconstructive techniques and technology are increasingly used in parotid surgery. The aim of this study was to determine the surgeon-modifiable factors which impact the rates of post-operative complications following parotidectomy for benign pathology.

METHODS

A retrospective cohort study of patients undergoing parotidectomy for benign pathology by or under the supervision of the senior author between 2006 and 2019 was performed. Clinicopathological variables, operative techniques and post-operative complications were recorded using standardized templates. Multivariable logistic regression models were used to obtain odds ratios (ORs) whilst adjusting for the effect of other clinically relevant covariates.

RESULTS

In total, 357 parotidectomies were performed. Independent factors associated with post-operative facial paresis were re-operative surgery (OR 3.51, 95% CI 1.19-10.33, P = 0.023), nerve integrity monitoring (OR 0.50, 95% CI 0.26-0.99, P = 0.046) and operation type, with focused tumour dissection (FTD) having the lowest rate of paresis (OR 0.19, 95% CI 0.040-0.92, P = 0.038) compared to limited parotidectomy. Factors associated with reduced wound complications on adjusted analysis were dermofat grafting (OR 0.10, 95% CI 0.01-0.72, P = 0.023), lesion size (OR 0.68, 95% CI 0.50-0.92, P = 0.01) and FTD (OR 0.16, 95% CI 0.05-0.59, P = 0.005) compared to limited parotidectomy.

CONCLUSION

FTD, nerve integrity monitoring and dermofat grafting are surgeon-modifiable variables associated with lower rates of post-operative complications following parotidectomy for benign pathology. However, the benefit of these operative techniques relies on their appropriate utilization by performing surgeons.

A case of tracheal pleomorphic adenoma misdiagnosed as asthma

A 51-year-old woman had an incidental finding of a tracheal tumor during oesophagogastroduodenoscopy following the diagnosis of asthma for 2 months. A computed tomography scan revealed a 15-mm tumor in the subglottis. Endoscopic resection was performed safely, and pleomorphic adenoma was diagnosed histologically. The patient’s condition was satisfactory 30 months after the procedure. Tracheal pleomorphic adenoma is rare and may be misdiagnosed as asthma. If the tumor is large, surgery may be required; however, endoscopic polypectomy may be effective if the tumor is small. Therefore, early diagnosis of tracheal pleomorphic adenoma is important. At the first visit, the flow–volume curve suggested upper airway obstruction, which should have raised the suspicion of an upper airway obstruction. In patients with suspected asthma, early pulmonary function testing is needed to substantiate asthma diagnosis and prevent an alternative diagnosis being missed.

Physiology, Pathology and Regeneration of Salivary Glands

Salivary glands are essential structures in the oral cavity. A variety of diseases, such as cancer, autoimmune diseases, infections and physical traumas, can alter the functionality of these glands, greatly impacting the quality of life of patients. To date, no definitive therapeutic approach can compensate the impairment of salivary glands, and treatment are purely symptomatic. Understanding the cellular and molecular control of salivary glands function is, therefore, highly relevant for therapeutic purposes. In this review, we provide a starting platform for future studies in basic biology and clinical research, reporting classical ideas on salivary gland physiology and recently developed technology to guide regeneration, reconstruction and substitution of the functional organs.

Pleomorphic Adenoma of the Palate: A Case Report

Pleomorphic adenoma is the most common benign tumor affecting the major salivary glands and infrequently arises from the minor salivary glands. It involves the parotid of the major salivary glands and the palate of the minor salivary glands. This article presents a case of pleomorphic adenoma of the palatal minor salivary gland treated successfully by surgical excision.

Right main bronchial pleomorphic adenoma: A case report and literature review

RATIONALE

Tracheobronchial benign tumors are uncommon; particularly, bronchial pleomorphic adenoma is one of the rarest benign tumors that develop in bronchus (only 7 reported cases, among which only 4 cases of pleomorphic adenoma were seen arising from right main bronchus).

PATIENT CONCERNS

In this report, a 38-year-old woman suffered from progressive shortness of breath for 5 years due to right main bronchial pleomorphic adenoma.

DIAGNOSES

The patient was diagnosed as right main bronchial pleomorphic adenoma based on chest computed tomography enhanced scan, bronchoscopy, and histological examination.

INTERVENTIONS

An electrosurgical snare was performed to resect the neoplasm and several APC were administered at the sites of the resection to provide hemostasis and further coagulate for the residual neoplasm.

OUTCOMES

The patient was free of symptoms and the lumen of right main bronchus was clear during the follow-up period for 10 months without any procedure-related complications.

LESSONS

Bronchial pleomorphic adenoma is extremely rare, however, we should take it into consideration if a patient suffered from shortness of breath without an exact cause.

Pleomorphic Adenoma of Minor Salivary Glands in Child

Introduction:

Tumors of salivary glands are very rare in children overall, and rarely in minor salivary glands. Among them pleoomorphic adenoma (PA) is the most common benign tumor of salivary glands in children and it acounts 60% of all salivary neoplasms, frequently found in major salivary glands (85 %) and rarely in minor salivary glands (10-15%). PA appears as painless oval mass, elastic consistency and smooth surface. It characterized by slow evolution of growing. The diagnosis can be confirmed only by histopathological features, after total excision of the lesion.

Case report:

This case report present the uncommon case of the formation well circumscribed in upper lip region, nearby the frenulum labii oris superior in 10 years old school girl. After clinical intraoral examination of the formation approximately 2cm in size the surgical treatment has been done and histopathologic analysis resulted as PA.

Conclusion:

Long term follow-up examination is necessary due to possible recurence or malignancy alteration.

Complications after superficial parotidectomy for pleomorphic adenoma

Background

The significance of complications after superficial parotidectomy remains unclear, since prospective studies are lacking. The aim of this study was to evaluate facial nerve dysfunction and other postoperative complications after superficial parotidectomy for pleomorphic adenoma of the superficial lobe and to identify the associated risk factors.

Material and Methods

Prospective and descriptive clinical study on 79 patients undergoing formal superficial parotidectomy with the modified facelift incision, dissection of the facial nerve and reconstruction with the superficial musculoaponeurotic system flap. Function of the facial nerve using the House-Brackmann scale and the intra- and postoperative complications were recorded at 1 week and 1, 3, 6 and 12 months. A descriptive, inferential and binary logistic regression analysis were performed for the variables facial nerve dysfunction, tumor size and location, clinical presentation and duration of surgery.

Results

77.2% of the patients presented facial paresis at 1 week, with the marginal-mandibular branch being the most commonly affected (64.5%). 94.9% recovered the facial function at 6 months and 100% at 12 months. A statistically significant relationship was found between the appearance of facial paresis and tumor location in the superior lateral area of the superficial lobe, size >2 cm and prolonged operative time. None of the remaining variables showed significant differences at any study timepoint. At 12 months, 57% of patients had recovered tactile sensitivity in the earlobe. The clinical occurrence of Frey’s syndrome was 11.4%.

Conclusions

Despite the high incidence of postoperative facial paresis at 1 week, its magnitude was low and the recovery time was short. Tumor location in the parotid superficial lobe upper area, size and prolonged operative time are risk factors that can worsen facial paresis at different study timepoints. The knowledge of these complications is relevant for patient´s counseling and to achieve better long-term outcomes.

Key words:Superficial parotidectomy, pleomorphic adenoma, parotid gland, facial nerve paralysis, postoperative complications.

Soft Palate Pleomorphic Adenoma of a Minor Salivary Gland: An Unusual Presentation

Approximately 10% of pleomorphic adenomas occur in the minor salivary glands with the palate being the most common site. Pleomorphic adenomas account for the majority of palatal tumours; however, minor salivary gland tumours have a higher risk of malignancy compared to tumours of the major salivary glands, so appropriate diagnostic evaluation should be prompt. We present a case of a 52-year-old man with a longstanding history of a soft palate pleomorphic adenoma which required excision under general anaesthetic via a mandibular swing approach. As well as the surgical approach to access this tumour; this case is unique as it is the largest soft palate pleomorphic adenoma reported in the literature. We discuss the appropriate preoperative investigations and airway considerations for this patient, as well as the factors to consider when planning operative management of palatal tumours.

Clinicopathologic and Surgical Study of Pleomorphic Adenoma of the Parotid Gland: Analysis of Risk Factors for Recurrence and Facial Nerve Dysfunction

PURPOSE

To determine whether clinicopathologic or surgical features are risk factors for recurrence and facial nerve dysfunction in pleomorphic adenoma (PA) of the parotid gland.

PATIENTS AND METHODS

The records of 198 patients surgically treated for a PA of the parotid gland from 1999 through 2013 were retrospectively reviewed to identify patients who developed a tumor recurrence. The Fisher exact test and Mann-Whitney U test were used to analyze patient characteristics between recurrent and non-recurrent PAs. Logistic regression was used to determine the risks of recurrence and facial nerve dysfunction.

RESULTS

Twenty-three patients (11.6%) developed a recurrence. Patients with tumor recurrence were notably younger than patients without recurrence. Of the 14 patients who underwent enucleation, 11 (78.6%) developed residual disease, as did 10 of 165 patients (6%) managed by a superficial parotidectomy (P < .0005). Furthermore, the risk of residual disease was 9.3 to 21.6 times higher in patients who underwent enucleation than in those who underwent a total or superficial parotidectomy. For tumor histology, recurrence was observed in 3 (15.8%) of the 19 cellular types, 18 (11.5%) of 157 classic cases, and 1 (4.8%) of 21 myxoid cases (P = .5). The risk of recurrence with positive resection margins was 49 times higher than with negative margins (P = .001).

CONCLUSION

Young age, enucleation, and positive margins are risk factors for residual pleomorphic adenoma, and surgical technique and histomorphologic features are associated with increased facial nerve dysfunction.

Benign tumors of the parotid gland: a retrospective study of 339 patients

AIM

Among 339 patients operated for benign tumor of the parotid gland: the recurrences and the postoperative complications rates were compared WITH those published in literature.

MATERIALS AND METHODS

About 339 patients operated: 274 primarily and 65 for recurrence or residual tumor.

VARIABLES

sex, age, surgical techniques, pre- or postoperative radiotherapy, histology, size and localization of the tumors, disease free intervals, recurrences and postoperative complications.

RESULTS

177 men and 162 women. Median age: 55 years and mean follow-up: 10.4 years. About 39 patients had adjuvant radiotherapy (11.5%). After primary surgery, four patients experienced recurrences (1.5%). After salvage surgery, eight patients recurred (12.3%). The recurrence rate was the highest among pleomorphic adenomas. Facial paralysis was more frequent after salvage surgery.

DISCUSSION

Recurrence rate 10 years later was lower after primary than after salvage surgery (p = 0.01). There was no relation between adjuvant radiotherapy and recurrence rate probably because the low rate of recurrences.

CONCLUSION

Recurrence rate after primary surgery is lower after superficial or total parotidectomy than after other surgical techniques. Pleomorphic adenomas have the highest rate of recurrences. Age and sex have no significant influence over the rate of recurrences. The most frequent postoperative complications are facial paralysis and Frey's syndrome.

Partial Superficial, Superficial, and Total Parotidectomy in the Management of Benign Parotid Gland Tumors: A 10-Year Prospective Study of 205 Patients

PURPOSE

The aim of this report is to present an overview of the authors' experience in treating parotid gland tumors for a period of 10 years. This report describes patients' demographics, surgical outcomes, and complications and discusses the management of benign disease with particular emphasis on the importance of facial nerve dissection.

PATIENTS AND METHODS

A total of 205 consecutive patients with different parotid gland tumors underwent surgery at Northampton General Hospital (Northampton, UK) from October 2000 to November 2010. Data were prospectively collected and entered into an electronic database. Patients' demographics, clinical tumor size, type of operation, fine-needle aspiration result, facial nerve status, final histopathologic report, and intraoperative and postoperative complications were recorded and analyzed.

RESULTS

This study confirmed that good results in low recurrence rate and minimal risk of facial nerve weakness can be achieved with operations less aggressive than traditional superficial parotidectomy, such as partial superficial parotidectomy. Transient facial nerve palsy was significantly more frequent after total (40%; P < .001) and superficial (28%; P < .05) parotidectomy, respectively, than after partial superficial parotidectomy (9.6%).

CONCLUSION

Because the risk or recurrence is higher when surgery is performed by inexperienced surgeons, the authors advocate that parotid gland surgery should be performed by adequately trained operators and the surgical specimen ideally should be examined by a histopathologist experienced in the diagnosis of salivary gland tumors. Recurrence rate for these tumors increases with time; therefore, long-term follow-up is required for these patients.

Preoperative evaluation and surgical planning of submandibular gland tumors

BACKGROUND

Roughly half of submandibular gland neoplasms are malignant. Because preoperative information on the nature of these tumors remains limited, both preoperative evaluation and assessment of the extent of primary surgery warrant guidelines that are more accurate.

METHODS

We evaluated the preoperative examinations and management of all submandibular gland neoplasms treated surgically at the Helsinki University Hospital between 2000 and 2010.

RESULTS

Of the 83 tumors, 58 (70%) were benign and 25 (30%) were malignant. Of the benign tumors, 54 (93%) were pleomorphic adenomas. The cytology in 8 patients (10%) was class IV or V, and in 12 patients was class III; the tumors in 9 of these 12 patients turned out to be malignant. Of all malignancies, 10 (40%) required additional more extensive surgery.

CONCLUSION

Ultrasound-guided fine-needle aspiration cytology (FNAC) proved useful, with limitations, in preoperative examination. Surgeons should always obtain wide margins whenever possible, even when clinical means or cytology indicates no malignancy. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1071-1077, 2017.

Altered expression of apoptosis-regulating miRNAs in salivary gland tumors suggests their involvement in salivary gland tumorigenesis

Salivary gland tumors comprise a heterogeneous group of lesions with different histological features and diverse clinical pathophysiology. They account for about 3% of all head and neck tumors. Apoptosis plays an important role during morphogenesis of glandular structures, including that of the salivary gland. Recent studies have demonstrated that several microRNAs (miRNAs) are involved in the control of apoptosis. The aim of the present study was to determine the expression of apoptosis-related miRNAs (miR-15a, miR-16, miR-17-5p, miR-20a, miR-21, miR-29, and miR-34) and their target mRNAs in 25 pleomorphic adenomas, 23 mucoepidermoid carcinomas, and 10 non-neoplastic salivary gland samples by real-time RT-PCR. We observed upregulation of miR-15a, miR-16, miR-17-5p, miR-21, miR-29, and miR-34a in pleomorphic adenomas. The expression of miR-21 and miR-34a was upregulated in 91 and 74% of mucoepidermoid carcinomas, respectively. Downregulation of miR-20a was observed in 75% of pleomorphic adenomas and in 57% of mucoepidermoid carcinomas. APAF1, BAX, BCL2, BID, CASP2, CASP8, DIABLO , and TP53 transcripts were upregulated in both tumor types. BAD transcripts were upregulated in pleomorphic adenomas. CASP3 and CASP6 transcripts were upregulated in mucoepidermoid carcinomas. BCL2, CASP2, CASP6, and CASP8 proteins were mostly absent in mucoepidermoid carcinomas but expressed in few cells in pleomorphic adenomas. Our study provides evidence of alterations in the expression of apoptosis-regulating miRNAs in salivary gland tumors, suggesting possible involvement of these microRNAs in salivary gland tumorigenesis.

Recurrent Pleomorphic Adenoma of the Parotid Gland

Pleomorphic adenoma is the most common type of salivary gland tumor and the most common tumor of the parotid gland. Because of its propensity for invasion, pleomorphic adenoma of the parotid requires superficial parotidectomy or total parotidectomy to minimize the risk of tumor recurrence. We report a case of pleomorphic adenoma of the parotid gland with repeated recurrences. A 23-year-old male patient presented with a protruding neck mass. Six years prior to this presentation, the patient had undergone superficial parotidectomy for the removal of pleomorphic adenoma of the right parotid gland at our institution. The patient experienced recurrence at 17 months after the initial resection, which required a total parotidectomy with partial resection of the facial nerve. Pathologic examination revealed histologic findings consistent with pleomorphic adenoma across the surgical specimen from all three of the operations. The patient suffered from facial nerve paralysis, with facial expressions partially recovered over a year.

Pleomorphic Adenoma of Cheek Masquerading as Fibrolipoma - Case Report with Review

Salivary gland tumours are rare, comprising 3% of head and neck tumours, of which Pleomorphic Adenoma (PA) constitutes 70-80%. It accounts for 53-74% of parotid tumours, 44-68% submandibular gland tumours and 38-43% of minor salivary gland tumours. It usually presents as painless, firm, slow growing mobile mass. Various diagnostic modalities for early detection of the tumour include FNAC, Ultrasonography, CT and MRI. The choice of treatment of pleomorphic adenoma of the minor salivary glands depends on the aggressiveness of the tumour, the extension of the mass, and its relation with the vital structures. Here, we report a rare case of pleomorphic adenoma of minor salivary glands of cheek in a 40-year-old male patient with emphasis on various diagnostic modalities.

Radiotherapy for benign disease; assessing the risk of radiation-induced cancer following exposure to intermediate dose radiation

Most radiotherapy (RT) involves the use of high doses (>50 Gy) to treat malignant disease. However, low to intermediate doses (approximately 3-50 Gy) can provide effective control of a number of benign conditions, ranging from inflammatory/proliferative disorders (e.g. Dupuytren's disease, heterotopic ossification, keloid scarring, pigmented villonodular synovitis) to benign tumours (e.g. glomus tumours or juvenile nasopharyngeal angiofibromas). Current use in UK RT departments is very variable. This review identifies those benign diseases for which RT provides good control of symptoms with, for the most part, minimal side effects. However, exposure to radiation has the potential to cause a radiation-induced cancer (RIC) many years after treatment. The evidence for the magnitude of this risk comes from many disparate sources and is constrained by the small number of long-term studies in relevant clinical cohorts. This review considers the types of evidence available, i.e. theoretical models, phantom studies, epidemiological studies, long-term follow-up of cancer patients and those treated for benign disease, although many of the latter data pertain to treatments that are no longer used. Informative studies are summarized and considered in relation to the potential for development of a RIC in a range of key tissues (skin, brain etc.). Overall, the evidence suggests that the risks of cancer following RT for benign disease for currently advised protocols are small, especially in older patients. However, the balance of risk vs benefit needs to be considered in younger adults and especially if RT is being considered in adolescents or children.

Pleomorphic Adenoma of the External Auditory Canal: A Rare Presentation

A 55-year-old male presented with a nine-month history of gradually enlarging, painless mass in the right external auditory canal associated with hearing loss and occasional bleeding. Examination demonstrated complete obstruction of the outer 1/3 of the external auditory canal by a firm, pink, rubbery mass. CT scan of the temporal bone showed tumor mass with no evidence of bone destruction. The tumor was excised and histopathology confirmed a diagnosis of ceruminous pleomorphic adenoma of the external auditory canal. Six months following the surgery, patient is free of any recurrent disease.

Basal cell adenoma-clinicopathological, immunohistochemical analysis and surgical considerations of a rare salivary gland tumor with review of literature

Introduction:

Basal cell adenoma (BCA) of the salivary glands is a rare benign salivary gland tumour. Differentiation of BCA from varied entities involving maxillofacial area is mandatory.

Aim:

To analyze the clinicopathological, histopathologic features, immunohistochemcal analysis and surgical considerations of this rare entity.

Materials and Methods:

This study included 12 cases of BCA from archives of department reported over the period of 13 years. All the pertaining clinicopathologic features such as incidence, age, sex and site of lesions were assessed. Tissue sections were stained by using panel of immunohistochemical markers, i.e. Pan CK, CK 5/6 and S100, Calponin, p63, CD 117 and smooth muscle actin.

Results:

BCA was observed in 26-52 years age group (mean age, 38.75 years) with female propensity of 7:5 male to female ratio. It is seen more commonly in parotid gland, followed by upper lip, buccal mucosa and palate. Solid type is the most common histopathologic type followed by tubular, membranous and trabecular. Only one case of membranous type of BCA showed recurrence. Pan CK, CK 5/6 showed strong immunoreactivity, calponin showed moderate staining, p63 and Ki-67 mild staining, whereas CD 117 and SMA showed negative immunostaining.

Conclusion:

Vigilant comprehensive analysis of all the pertaining clinicopathologic and histopathologic features and immunohistochemical analysis are required for differentiating from other lesions with basaloid differentiation having varying prognosis.

Pleomorphic adenomas: post-operative radiotherapy is unnecessary following primary incomplete excision: a retrospective review

BACKGROUND

Current standard treatment of Pleomorphic Salivary Adenoma (PSA) of the Parotid Gland is by surgical excision. The management of incomplete excision remains undecided with post-operative radiotherapy advocated by some and observation by others.

METHODS

190 patients who underwent resection of PSA of the parotid gland within the West of Scotland region from 1981 to 2008 were identified and data collected.

RESULTS

78/190 patients had a primary incomplete excision. 25/78 received post-operative radiotherapy and 53 were observed. Recurrences occurred in 11/53 in those observed and in 1/25 of those who received radiotherapy. 21/25 complained of significant side effects from the radiotherapy. 38 surgeons performed 190 procedures, with a range of experience from 1 to28 procedures.

CONCLUSIONS

Radiotherapy does appear to reduce recurrence with incomplete excision, however it is associated with significant side effects. We therefore feel radiotherapy should not be routinely recommended. Subspecialisation should be adopted to increase the operating surgeon's experience.

A novel cell line derived from pleomorphic adenoma expresses MMP2, MMP9, TIMP1, TIMP2, and shows numeric chromosomal anomalies

Pleomorphic adenoma is the most common salivary gland neoplasm, and it can be locally invasive, despite its slow growth. This study aimed to establish a novel cell line (AP-1) derived from a human pleomorphic adenoma sample to better understand local invasiveness of this tumor. AP-1 cell line was characterized by cell growth analysis, expression of epithelial and myoepithelial markers by immunofluorescence, electron microscopy, 3D cell culture assays, cytogenetic features and transcriptomic study. Expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) was also analyzed by immunofluorescence and zymography. Furthermore, epithelial and myoepithelial markers, MMPs and TIMPs were studied in the tumor that originated the cell line. AP-1 cells showed neoplastic epithelial and myoepithelial markers, such as cytokeratins, vimentin, S100 protein and smooth-muscle actin. These molecules were also found in vivo, in the tumor that originated the cell line. MMPs and TIMPs were observed in vivo and in AP-1 cells. Growth curve showed that AP-1 exhibited a doubling time of 3.342 days. AP-1 cells grown inside Matrigel recapitulated tumor architecture. Different numerical and structural chromosomal anomalies were visualized in cytogenetic analysis. Transcriptomic analysis addressed expression of 7 target genes (VIM, TIMP2, MMP2, MMP9, TIMP1, ACTA2 e PLAG1). Results were compared to transcriptomic profile of non-neoplastic salivary gland cells (HSG). Only MMP9 was not expressed in both libraries, and VIM was expressed solely in AP-1 library. The major difference regarding gene expression level between AP-1 and HSG samples occurred for MMP2. This gene was 184 times more expressed in AP-1 cells. Our findings suggest that AP-1 cell line could be a useful model for further studies on pleomorphic adenoma biology.

Pleomorphic adenoma presenting with conductive hearing loss in the ear canal: a case report and review of the literature

Introduction

Pleomorphic adenoma accounts for 65 percent of all salivary gland tumors. It has been identified in several anatomical regions, but pleomorphic adenoma arising in the ear canal, first described in 1951, is extremely rare.

Case presentation

A 40-year-old Japanese man’s left ear canal was obstructed by a pleomorphic adenoma that caused mild conductive hearing loss. The tumor was resected and he remains disease-free two years after surgery.

Conclusions

Pleomorphic adenoma usually arises from a major and minor salivary gland, but pleomorphic adenoma of the ear canal is derived from the ceruminous gland. We discuss the present case and 37 other case reports in our effort to clarify the clinical features and the course of pleomorphic adenoma in the ear canal.

[Radiation therapy for pleomorphic adenoma of the parotid]

Parotid pleomorphic adenoma is the most frequent tumor of salivary glands. The prognosis depends on the recurrences because they could lead to iatrogenic events (facial paralysis). Moreover the risk of malignant transformation increases with the number of local relapses. This article aims at reviewing histological and radiological criteria and the surgical techniques. To improve local control, adjuvant irradiation (in first intention or after recurrence) may be useful but is still controversial for benign tumors in young patients with a risk of radio-induced cancer. We listed studies in which adjuvant radiotherapy was used so as to define its place in the treatment strategy. Prognostic factors were found by some authors. Other studies have to be done before strong evidence-based recommendations are issued.

Tumours of the lacrimal gland. Epidemiological, clinical and genetic characteristics

Tumours of the lacrimal gland are rare, but the prognosis may be grave. To date, no population-based incidence and distribution data on lacrimal gland tumours exist. In addition, almost nothing is known about the genetic profile of epithelial tumours of the lacrimal gland. We collected specimens and clinical files on all biopsied lacrimal gland lesions in Denmark over a 34-year period and re-evaluated the diagnosis to provide updated population-based incidence rates and epidemiological characteristics. Clinical data regarding symptoms, clinical examinations, treatment and follow-up were collected for patients with adenoid cystic carcinoma (ACC), pleomorphic adenoma (PA), carcinoma ex pleomorphic adenoma (Ca-ex-PA) and mucoepidermoid carcinoma (MEC). Using RT-PCR, FISH, immunohistochemistry, Q-PCR and high-resolution array-based comparative genomic hybridization (arrayCGH) we explored the genetic characteristics including copy number alterations (CNA) in ACC, PA, Ca-ex-PA and MEC. The incidence of biopsied lacrimal gland lesions was 1.3/1,000,000/year, and ~50% were neoplastic lesions. Of these, 55% were malignant tumours with epithelial tumours as the most frequent. The overall incidence was increasing, and this was caused by an increase in biopsied non-neoplastic lesions. We found that 10/14 ACCs either expressed the MYB-NFIB fusion gene and/or had rearrangements of MYB. All ACCs expressed the MYB protein. ACC was characterized by recurrent copy number losses involving 6q, 12q and 17q and gains involving 19q, 8q and 11q. ArrayCGH revealed an apparently normal genomic profile in 11/19 PAs. The remaining 8 PAs had recurrent copy number losses involving 1p, 6q, 8q and 13q and gain involving 9p. PA expressed PLAG1 in all tumours whereas only 2/29 tumours expressed HMGA2. Ca-ex-PA was characterized by recurrent copy number gain involving 22q. PLAG1 was expressed in 3/5 Ca-ex-PA whereas none of these tumours expressed HMGA2. MEC expressed the CRTC1-MAML2, and this fusion was found to be tumour-specific for lacrimal gland MEC. In conclusion, lacrimal gland lesions that require pathological evaluation are rare in the Danish population, and the incidence rate of biopsied benign lesions is increasing. Epithelial tumours of the lacrimal gland are molecularly very similar to their salivary gland counterparts in the expression of the tumour-specific fusion genes and in their genomic imbalances as demonstrated by arrayCGH. MYB-NFIB is a useful biomarker for ACC and MYB, and its downstream target genes may be potential therapeutic targets for these tumours.

Epithelial tumours of the lacrimal gland: a clinical, histopathological, surgical and oncological survey

Epithelial tumours of the lacrimal gland represent a large spectrum of lesions with similarities in clinical signs and symptoms but with different biological behaviour and prognosis. They are rare, but with aggressive malignant potential. Tumours of the lacrimal gland may present with swelling of the lacrimal gland, displacement of the eyeball, reduced eye motility and diplopia. Pain and symptoms of short duration before the first ophthalmic consultation are characteristic of malignant tumours. The histological diagnosis determines the subsequent treatment regimen and provides important clues regarding the prognosis. The purpose of this paper is to describe the various primary epithelial tumours of the lacrimal gland. In the first part of the review, the frequency, demographics, clinical presentation and diagnostic features are described. In the second part, primarily tumour-specific histological characteristics are given. Finally, treatment modalities including surgical procedures and medical oncology as well as prognosis are discussed.