Epithelial-myoepithelial duct carcinoma of salivary glands: a follow-up and cytophotometric study of 21 cases

Epithelial-Myoepithelial Carcinoma of the Minor Salivary Glands: Case Series with Comprehensive Review

Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland tumor that is histologically characterized by biphasic tubular structures composed of inner ductal and outer clear myoepithelial cells, which is especially uncommon in the minor salivary glands (MSG). Because of its histologic variety, complexity, and heterogeneity, it is sometimes challenging to make the accurate diagnosis. Here, we report a literature review of EMC of the MSGs with our experience of two cases. Incisional biopsy was suggestive of pleomorphic adenoma in Case 1 and pleomorphic adenoma or a low-grade salivary gland carcinoma in Case 2. Both cases were performed intraoral tumor resection, and they have good postoperative courses and are alive with no evidence of local recurrence or metastasis at 31 and 16 months, respectively. Considering that the anatomy, structure, and size of salivary glands are quite different from MSGs, it might be difficult to predict EMCs of the MSG similarly to EMCs of the major salivary glands. This comprehensive review also reports the features of EMC of the MSG cases and the trends of diagnosis and discusses treatment strategy.

Epithelial-myoepithelial carcinoma of the parotid gland with primary lung cancer: A rare case report

INTRODUCTION

Epithelial-myoepithelial carcinoma (EMC) is a rare, low-grade malignancy that occurs primarily in the parotid gland and is most common in women aged 60 to 70 years. Cases of parotid EMC have been reported previously. Furthermore, some studies have suggested an increased risk of salivary gland tumors with secondary primary malignancies. There have been few reports of parotid EMC with other primary tumors.

PATIENT CONCERNS

A 62-year-old Chinese man visited the hospital with a complaint of a mass on his left cheek that had persisted for 20 years. Routine pulmonary computed tomography showed a local ground glass shadow in the lower lobe of the right lung.

DIAGNOSIS

The pathological diagnosis of lung was right lower lobe lung adenocarcinoma (pT1N0). Immunohistochemistry analysis showed that cytokeratin (CK)-7, NapsinA, and thyroid transcription factor-1 tested positive, while CK5/6, P40, and ALKD5F3 tested negative. The pathological diagnosis of left parotid gland: EMC. On immunohistochemistry staining, the outer cells expressed myoepithelial markers, such as CK5/6, P63, smooth muscle actin, while the inner cells expressed glandular epithelial markers, such as low-molecular-weight CK7 and CK8.

INTERVENTIONS

The patient underwent resection of the lung and parotid tumors, and received preventive radiotherapy in the parotid gland area.

OUTCOMES

The patient is in good condition. No symptom recurrence, distant metastatic spread or significant toxicity occurred during or after the treatment. The patient remains under regular surveillance.

CONCLUSION

We report a rare case of parotid EMC with a second primary lung adenocarcinoma. This case is the third case of primary lung cancer associated with parotid EMC reported to date and the first to be reported in nearly 30 years.

Epithelio- Myoepithelial Carcinoma of Masseteric Space: a Case Report

Epithelio-myoepithelial carcinoma (EMEC) is a very rare malignancy of the salivary gland which comprises less than 1 % of salivary gland tumors. In the parapharyngeal space they can either arise from the deep lobe of parotid gland or de novo from minor salivary glands. We present a case of epithelio-myoepithelial carcinoma of parapharyngeal and masseteric space. The case is important for its rarity of presentation and we discuss the surgical difficulties and morbidities.

Cytomorphologic Attributes of Epithelial Myoepithelial Carcinoma of Nasal Cavity - A Rare Tumor with Unusual Clinical Presentation

Epithelial-Myoepithelial Carcinoma (EMC) is a rare low grade epithelial malignancy of major Salivary Glands (SG). Though the histomorphology of this tumor is distinct, unusual location and clinical presentation may pose diagnostic difficulties especially when this lesion is first encountered at cytology. We report a case of 60-year-old female presenting with nasal obstruction of three months duration. At FNAC the diagnosis of EMC was suggested and it was confirmed on histopathology. We present this case highlighting the cytomorphologic attributes of this rare tumor occurring at an extremely uncommon location - Nasal cavity.

Mucoepidermoid Carcinoma of Major and Minor Salivary Glands

Forty-three consecutive cases of mucoepidermoid carcinoma of the major and minor salivary glands were studied to evaluate the influence of the following parameters on prognosis: age, sex, location, local extension, mitotic counts, vascular invasion, grade of differentiation, and nuclear DNA ploidy assessed by image cytometry. The age of the patients ranged between 7 and 84 years. Twenty-eight patients were male and 15 female. Thirty-five tumors were in the major salivary glands and 8 in the minor glands of the oral cavity. According to Healey's criteria, 14 tumors were classified as grade 1, 17 as grade 2, and 12 as grade 3 and, according to the 1990 World Health Organization proposal, 17 tumors were classified as low-grade and 26 as high-grade neoplasms. Image cytophotometric DNA analysis revealed 15 euploid and 6 aneuploid tumors. The range of the follow-up study was 3-156 months (mean, 40.7 months). The 5- year actuarial survival for each of the above-cited parameters was: 100% and 59.1 % for patients aged less than 20 and over 55 years, respectively; 49.6% for male and 85.7% for female patients; 61.3% for major gland and 73.3% for minor gland tumors; 100% and 57.5% for intraglandular and extraglandular major salivary gland neo plasms, respectively; 46.2% for cases with high mitotic rate and 83.1% for those with low mitotic rate; 38.7% and 81.6% for tumors respectively with and without vascular invasion; 100% for grade 1 and 64.7% for grade 2; none of the patients with grade 3 neoplasms were alive at 5 years. Survival was of 100% for low-grade and 40.7% for high-grade tumors. Survival was 92.8% for euploid tumors and 61.3% for the aneuploid ones. In conclusion, survival of patients with mucoepidermoid carcinoma is significantly related to the histological grade of differentiation, the mitotic count, the presence of vascular invasion and the DNA ploidy of the tumor cells. Int J Surg Pathol 1(1):3-12, 1993

Epithelial-myoepithelial carcinoma arising from the subglottis: a case report and review of the literature

Background

Epithelial-myoepithelial carcinoma is an extremely rare disease that usually occurs in the parotid gland but can occur in a variety of sites such as the nasal cavity, paranasal sinus, and base of the tongue.

Case presentation

We report a rare case of epithelial-myoepithelial carcinoma, which developed in the subglottic region. A 78-year-old Korean woman visited our hospital complaining of hoarseness, which had developed 1 month previously. Flexible laryngoscopy showed a round mass that blocked approximately 80 % of the tracheal diameter. Complete excision of the mass was carried out under general anesthesia, using a transoral approach. Epithelial-myoepithelial carcinoma was diagnosed following immunohistochemical analysis.

Conclusions

We report a rare case of epithelial-myoepithelial carcinoma that occurred in the subglottic region. To the best of our knowledge, only one other case has been reported since this disease was first identified approximately 40 years ago.

Epithelial-myoepithelial carcinoma of the parotid gland: Clinicopathological aspect, diagnosis and surgical consideration

The present paper describes the clinical and pathological features of epithelial-myoepithelial carcinoma (EMC) of the parotid gland. This rare tumor represents <1% of all salivary gland tumors and arises most commonly in the parotid gland, but it has also been described in the submandibular gland, minor salivary glands and palate. EMC is considered to be a low-grade malignant tumor that may commonly recur locally after resection in 23-50% of cases. The complex and varied morphological expression of this neoplasm has attracted numerous investigators, who have presented valuable but often contradictory data. After an in-depth analysis of the clinicopathological aspects of EMC, we speculate that adequate resection with negative soft-tissue margins is the minimum recommended and necessary therapy.

Bilateral epithelial-myoepithelial carcinoma: an extraordinary tumor of the paranasal sinuses

A 54-year-old woman presented with a 6-month history of swelling on the right side of her face. On physical examination she was found to have a huge mass in the right nasal cavity. Magnetic resonance images of the paranasal sinuses revealed a soft tissue mass in the right maxillary sinus and a mass was also seen in the left maxillary sinus. On histopathologic examination, the tumor had a lobular structure with infiltrating margins. Two cell types, an outer layer of myoepithelial and an inner layer of duct-like cells, were found. On immunohistochemical examination, myoepithelial cells stained positively for calponin, p63, GFAP, S-100 protein, alpha-smooth muscle actin cytokeratin-14. The tumors were resected completely and no recurrence or metastasis was found 30 months after surgery. We describe here an unusual case of epithelial-myoepithelial carcinoma (EMC) arising from the paranasal sinuses. This is the first case report in the literature describing bilateral EMC in the maxillary sinuses.

Clear cell predominant epithelial-myoepithelial carcinoma of the hard palate - role of immunohistochemistry

Epithelial-myoepithelial carcinoma (EMC) arising from the minor salivary gland of the hard palate is very rare. A 34-year-old lady presented with a nodular swelling in the hard palate. Histopathologically, a diagnosis of clear cell predominant EMC was suggested. Immunohistochemistry demonstrated the biphasic nature of the tumor and confirmed the diagnosis of EMC.

Carcinome épithélial–myoépithélial de la cavité nasale

OBJECTIVES

Epithelial-myoepithelial carcinoma is a rare tumor of the salivary glands with an incidence of less than 1%. Most cases arise in the parotid gland. Extraoral location is exceptional. The purpose of this study was to describe a case with nasal location, which is exceptionally reported in the literature.

MATERIALS AND METHODS

We report a case of epithelial-myoepithelial carcinoma arising in the nasal cavity of a 54-year-old woman.

RESULTS

The woman presented with right recurrent epistaxis and on nasal endoscopic examination was found to have a polypoid tumor in the right nasal cavity. The CT-scan demonstrated a soft tissue mass without extension to the rhinopharynx or bony destruction. Histopathologic examination revealed the tumor to consist of a mixture of a solid, tubular, and trabecular structures with a double-layered arrangement of inner eosinophilic cells and outer clear cells. Dual differentiation toward myoepithelial and epithelial cells was confirmed immunohistochemically.

CONCLUSION

The occurrence of epithelial-myoepithelial carcinoma in the nasal cavity is possible. In published cases, no recurrence or metastasis has been reported in this location.

Epithelial-myoepithelial carcinoma: a review of the clinicopathologic spectrum and immunophenotypic characteristics in 61 tumors of the salivary glands and upper aerodigestive tract

To further define the clinicopathologic spectrum of epithelial-myoepithelial carcinoma (EMCa), we report the gross, histologic, and immunophenotypic characteristics of 61 tumors seen within a 30-year-period. The mean age at presentation was 60.9 years, with a female predominance (1.5:1). The most common sites were parotid (62.1%), sinonasal mucoserous glands (10.3%), palate (8.6%), and submandibular (8.6%). Most EMCas showed a characteristic nodular/multinodular growth pattern and classic biphasic tubular histology. However, new morphologies in EMCa such as ancient change (8.2%), "Verocay"-like change (3.3%), and sebaceous differentiation (13.1%) were noted. Specific histologic variants were dedifferentiated EMCa (3.3%), oncocytic EMCa (8.2%), EMCa ex pleomorphic adenoma (1.6%), double-clear EMCa (3.3%), and EMCa with myoepithelial anaplasia (3.3%). All cytokeratin cocktails selectively highlighted the epithelial component well. Of the myoepithelial markers, p63, smooth muscle actin and vimentin performed best. Bcl-2 and c-kit were frequently positive (66.7% and 69.2%, respectively). p53 was highly expressed only in 1 dedifferentiated EMCa. The recurrence rate was 36.3% (median disease-free survival 11.34 y), but death was rare with 5-year and 10-year disease-specific survivals of 93.5% and 81.8%, respectively. The most important univariate predictors of recurrence were margin status (log rank P=0.006), angiolymphatic invasion (P=0.002), tumor necrosis (P=0.004), and myoepithelial anaplasia (P=0.038). Thus, EMCa is generally a low-grade tumor with a broader morphologic spectrum than previously thought, with several key features predictive of recurrence. Immunohistochemistry can aid diagnosis by highlighting the biphasic nature of the tumor.

Epithelial–myoepithelial carcinoma of the submandibular gland with symptomatic lung metastases treated with chemotherapy

This report concerns a patient with symptomatic lung metastases from an epithelial-myoepithelial carcinoma of the submandibular gland. Although the efficacy of chemotherapy is unknown in this disease, our patient was treated with cisplatin combined with 5-fluorouracil and later with paclitaxel and cyclophosphamide. Chemotherapy allowed disease stabilization and relief of the pulmonary symptoms. This is the first report on the use of chemotherapy in this very rare salivary gland carcinoma.

Epithelial-myoepithelial carcinoma in the base of the tongue: a case report

OBJECTIVES

To report a rare case of epithelial-myoepithelial carcinoma (EMC) of a minor salivary gland originating in the base of the tongue, which is a highly unusual location.

STUDY DESIGN

This is a case report and a review of literature.

METHODS

A 76-year-old man was referred to our outpatient clinic with a 6-month history of a sensation of a foreign body in the pharynx. Endoscopic examination revealed a tumorous lesion 40 x 20 mm in the base of the tongue on the left side. A biopsy was performed, and the lesion was histologically identified as squamous cell carcinoma.

RESULTS

The patient underwent subtotal glossectomy, bilateral neck dissection, and reconstruction with a microvascularized rectus abdominis myocutaneous flap. The final diagnosis based on the histological and immunohistochemical findings was EMC. Because neither histological evidence of residual tumor in the surgical margin nor neck metastases were found, radiotherapy was not performed. No local recurrence or distant metastases have been found 19 months post-surgery.

CONCLUSION

We believe this report is the first description of EMC originating in the base of the tongue. We conclude that a wide surgical excision with a clear margin and close, prolonged follow-up are recommended for the treatment of EMC.

Salivary gland-like tumours of the breast: surgical and molecular pathology

Breast glands and salivary glands are tubulo-acinar exocrine glands that can manifest as tumours with similar morphological features, but that differ in incidence and clinical behaviour depending on whether they are primary in breast or salivary glands. Salivary gland-like tumours of the breast are of two types: tumours with myoepithelial differentiation and those devoid of myoepithelial differentiation. The first and more numerous group comprises a spectrum of lesions ranging from "bona fide" benign (such as benign myoepithelioma and pleomorphic adenoma), to low grade malignant (such as adenoid cystic carcinoma, low grade adenosquamous carcinoma, and adenomyoepithelioma), to high grade malignant lesions (malignant myoepithelioma). The second group comprises lesions that have only recently been recognised, such as acinic cell carcinoma, oncocytic carcinoma of the breast, and the rare mucoepidermoid carcinoma.

Primary salivary clear cell tumors--a diagnostic approach: a clinicopathologic and immunohistochemical study of 20 patients with clear cell carcinoma, clear cell myoepithelial carcinoma, and epithelial-myoepithelial carcinoma

CONTEXT

Primary salivary clear cell tumors comprise an uncommonly encountered subgroup of salivary neoplasia. We hypothesize that clear cell carcinoma does not represent a "monomorphic" variant of epithelial-myoepithelial carcinoma, but is distinct in terms of histogenesis and tumor biology.

OBJECTIVES

To compare the clinicopathologic features of 20 cases of salivary primary clear cell tumors, including 12 clear cell carcinomas (CCCs), 7 epithelial-myoepithelial carcinomas (EMECs), and 1 clear cell myoepithelial carcinoma (CCMEC); to investigate their interrelationship with regard to myoepithelial differentiation; and to offer a diagnostic approach for distinguishing between these entities.

DESIGN

Retrospective and prospective identification and review of patients diagnosed with primary salivary clear cell neoplasia and review of the English language literature.

SETTING

Three academic tertiary-care hospitals.

PATIENTS

We identified 12 patients with CCC, 7 with EMEC, and 1 with CCMEC. Patients included 11 men and 9 women, aged 30 to 88 years (median 72.5 years).

MAIN OUTCOME MEASURES

Immunohistochemical reactivity for S100, muscle-specific actin, and calponin; ultrastructural examination when feasible; review of patient charts; and telephone interviews to establish clinical outcome.

RESULTS

Clear cell carcinoma has a predilection for intraoral sites, whereas EMEC has a predilection for the parotid. All 3 of the tumor types studied have a propensity for locoregional recurrence, which can manifest decades after initial surgery. There were no mortalities among patients with CCC, even after pulmonary metastasis in 2 patients, confirming the indolent nature of this group of clear cell tumors. A meta-analysis of reported cases of CCC, EMEC, and CCMEC confirmed that EMEC and CCMEC have a much greater propensity for locoregional recurrence than CCC, despite the predilection of both for a more surgically accessible site (parotid). We found no definitive evidence of myoepithelial differentiation in CCC, indicating that it is probably morphogenetically distinct from EMEC and CCMEC, both tumors with diagnostically requisite myoepithelial differentiation.

CONCLUSIONS

The initial treatment of choice for CCC, CCMEC, and EMEC is surgical resection with negative margins. Locoregional recurrence should be treated aggressively, as it is still consistent with long disease-free intervals. The lack of myoepithelial differentiation in CCC is consistent with the concept that this tumor is histomorphogenically distinct from EMEC and that it is not merely a monomorphic variant.

Epithelial-myoepithelial carcinoma of the salivary gland--a low grade malignant neoplasm? Report of two cases and review of the literature

Epithelial-myoepithelial carcinomas (EMC) are rare neoplasms of the salivary gland with an incidence of less than 1% arising predominantly in the parotid gland. Although they are thought to be of low grade malignancy, fatal courses are described. We report a case of EMC of the parotid gland in a 58-year-old woman with an unfavorable course of this disease in long term follow-up. The malignant potential of this tumor is discussed. In addition, we include another case of EMC of the submandibular gland.

An unusual case of epithelial-myoepithelial carcinoma of the liver

The authors present an unusual case of an epithelial-myoepithelial carcinoma of the liver in a 67-year-old man who was admitted for resection of a gastric adenocarcinoma. At operation, a 3 x 3 cm mass in the right liver lobe was also removed. This mass consisted of duct-like structures with dual differentiation. The inner layer was composed of an epithelial lining, and the outer layer consisted of clear cells, all unrelated to the moderately well-differentiated gastric adenocarcinoma. The clear cells were positive for S-100 and alpha-smooth muscle actin, suggesting myoepithelial origin. The mass was considered to be low-grade epithelial-myoepithelial carcinoma. However, the patient had a history of an oral nodule present since childhood, resected 10 years previously. These slides were reviewed and revealed a mixture of clear cells and basal cells with squamous differentiation. In addition, there were duct-like structures with the two-layer pattern found in the liver tumor. This tumor had numerous mitotic figures and showed perineural invasion, suggesting a high grade of malignancy. These findings led to an interpretation of the oral tumor as also being epithelial-myoepithelial carcinoma, which had remained as "benign" for more than 50 years and subsequently underwent malignant transformation. During this long period, liver metastases may have occurred and remained low-grade. Alternatively, the liver and oral tumors may have arisen separately in the foregut during embryologic development, remaining low-grade until malignant transformation occurred.

Epithelial-myoepithelial carcinoma of the bronchus

An extremely rare case of epithelial-myoepithelial carcinoma (EMC) of a lobar bronchus in a 47-year-old female is reported. Grossly, the tumor formed a polypoid mass obstructing the bronchial lumen. Microscopically, it was composed of two cellular types--epithelial cells with eosinophilic cytoplasm and clear myoepithelial cells. Numerous tubules formed by an inner epithelial and outer myoepithelial layer were found. Focally, the tumor showed solid growth of clear cells. Prominent hyalinization of the stroma was found. The nature of the cells was confirmed by positive expression of cytokeratins and epithelial membrane antigen in epithelial cells and vimentin and smooth muscle actin in myoepithelial cells. Differential diagnosis of EMC includes a broad spectrum of salivary gland-type tumors. Furthermore, metastases of clear cell carcinoma of the kidney or thyroid, clear cell ("sugar") tumor of the lung, glandular form of carcinoid, bronchioalveolar adenocarcinoma with myoepithelial cells and pulmonary adenosquamous carcinoma with amyloid-like stroma must be distinguished from EMC. The tumor has neither recurred nor metastasised, a fact supporting the current opinion, that EMC is a tumor of low grade malignancy.

Clear cell neoplasms in salivary glands: clearly a diagnostic challenge

Although infrequent, salivary gland tumors with a dominant population of clear staining cells present problems in differential diagnosis. Mucoepidermoid carcinoma, acinic cell adenocarcinoma, "clear cell" oncocytoma, epithelial-myoepithelial carcinoma, clear cell adenocarcinoma, and metastatic renal cell carcinoma are considered in the differential diagnosis. This review focuses on this heterogenous group of clear cell neoplasms and attempts to clarify some of the features that help distinguish one neoplasm from another.

Prognostic significance of DNA ploidy in mucoepidermoid carcinoma

Thirty-four mucoepidermoid carcinomas were studied retrospectively with regard to histological and clinical parameters. In 28 of the tumors DNA patterns were also assessed using flow cytometry. Twenty-two of the 28 tumors (79%) were DNA diploid and 6 (21%) DNA aneuploid. Two tumors (7%) showed intratumoral DNA as indicated by different stemlines in specimens investigated from different parts of the tumor. DNA ploidy correlated significantly with cervical lymph node status (P < 0.01), but not with tumor size or histological grade. The mean S-phase value was 2.7% and was significantly higher in aneuploid samples than in diploid ones (P < 0.05). The recurrence rate was significantly lower for patients with stage I and II tumor compared with those with stage III and IV disease (P < 0.01). Five aneuploid tumors showed significantly higher recurrence rates (5/6) than the diploid ones (1/22) (P < 0.01). In univariate analysis for survival, only N stage tumor (P < 0.05) and tumor DNA ploidy (P < 0.0003) had significant prognostic influence. Thus, DNA ploidy seems to be a valuable parameter for evaluating the biological behavior of mucoepidermoid carcinomas of the salivary glands.

Epithelial-myoepithelial carcinoma of the palate

A case of epithelial-myoepithelial carcinoma (EMC) of the palate in a 72-year-old Japanese man is described. The patient had noticed swelling of the palate commencing about 20 years previously. Histologically, the tumor consisted of a proliferation of double-layered duct-like structures with two distinctive cell types. The inner layer was composed of eosinophilic epithelial cells, while the outer layer was composed of clear cells. Immunohistochemical analysis revealed that reaction products for total keratin were predominantly found in the cytoplasm of the inner epithelial cells, while those for S-100 protein and smooth muscle actin were observed only in the outer cells. Immunoreactive products for secretory component and lysozyme were found in some of the luminal contents and the inner cells of the tumor nests. These findings indicated this tumor to be an EMC of the palate, which had shown no aggressiveness over a twenty-year period prior to surgical excision.

Hybrid tumours of salivary glands. Definition and classification of five rare cases

Hybrid tumours are very rare tumour entities which are composed of two different tumour entities, each of which conforms with an exactly defined tumour category. The tumour entities of a hybrid tumour are not separated but have an identical origin within the same topographical area. In contrast, biphasically differentiated tumours are a mixture of two cellular patterns with a corresponding term in the tumour classification. Examples of a biphasic differentiation are: basaloid-squamous carcinoma, adeno-squamous carcinoma or sarcomatoid carcinoma, and epithelial-myoepithelial carcinoma, mucoepidermoid carcinoma or adenoid cystic carcinoma. Hybrid tumours must also be distinguished from the multiple occurrence of salivary gland tumours which can develop syn- or metachronously. In the tissue samples of more than 6600 salivary gland tumours covered by the Salivary Gland Register (Institute of Pathology, University of Hamburg, Germany) only 5 cases of hybrid tumours were recorded between 1965 and 1994. This means less than 0.1% of all registered tumours. Case 1 was a very rare example of a hybrid adenoma with differentiation as a basal cell adenoma and a canalicular adenoma of the parotid gland. The similar cellular origin of both types of adenoma may be an explanation for its development in a hybrid adenoma. Case 2 is a hybrid tumour with a composition of basal cell adenoma and a glandular type of adenoid cystic carcinoma. In both types of tumours the two cell types (duct-lining cells and modified myoepithelial cells) have a similar histogenetic origin. Therefore, the development of the both cell types in a hybrid tumour with two trends of differentiation is possible. Case 3 represents a hybrid adenoma as a mixture of a Warthin tumour and a sebaceous adenoma. Although inclusions of sebaceous cells are observed in Warthin tumours, this hybrid tumour shows a composition of two different epithelial structures in a varied mixture. Case 4 is a very rare and unique hybrid carcinoma with two absolutely different components: acinic cell carcinoma and salivary duct carcinoma. The poor prognosis of this hybrid carcinoma is determined by the salivary duct carcinoma. Case 5 represents a hybrid carcinoma whose two components have a similar histogenetical basis: epithelial-myoepithelial carcinoma and a glandular type of adenoid cystic carcinoma. Both carcinomas are composed of variable proportions of ductlining cells and myoepithelial cells.

Epithelial-myoepithelial carcinoma of the parotid gland. An unusual cause of ear canal stenosis

Epithelial-myoepithelial carcinoma (EMC) accounts for approximately one per cent of salivary gland tumours. This tumour is gaining wider recognition following inclusion into the WHO histological classification of salivary gland tumours in 1990. Salivary gland tumours characteristically present with an enlarging mass. We describe an unusual presentation of a salivary gland tumour with stenosis of the external ear canal in the absence of a palpable mass. EMC usually arises from the salivary glands but isolated cases have been described arising primarily from the paranasal sinuses, trachea and lacrimal gland. The management of this tumour is still evolving with surgical excision being the main-stay of treatment. The efficacy of radiotherapy has not yet been established but high local recurrence rates despite apparently adequate excision and the possibility of a multicentric origin of the tumour may herald an increasing role for radiotherapy in the future. We stress the importance of awareness of adjacent structures when considering the cause of cartilaginous canal stenosis.

Epithelial-myoepithelial carcinoma--report of a case arising in the nasal cavity

We present an extremely rare case of epithelial-myoepithelial carcinoma (EMC) arising in the nasal cavity. The patient was a 56-year-old Japanese male with a polypoid tumour arising from the nasal septum. Histopathological examination revealed the tumour to consist of a solid proliferation of clear-cells and, in some areas, small or elongated duct structures with a double-layered arrangement of inner cuboidal cells and outer clear-cells. Dual differentiation toward myoepithelial and ductal cells were confirmed immunohistochemically. The occurrence of EMC in the nasal cavity is possible and this entity should be generally recognized by surgical pathologists, not only those engaged in head and neck surgery.

Quantitative multivariate analysis of myoepithelioma and myoepithelial carcinoma

The nuclear DNA content and morphologic data of 30 surgical samples (eight normal parotid gland, 12 myoepithelioma, and 10 myoepithelial carcinoma) were analyzed by the IBAS II analysis system. The results suggest that there are relationships between tumor ploidy distribution and prognosis, and that correct pathologic diagnosis can be obtained by the IBAS image system.

Epithelial-myoepithelial carcinoma of the salivary glands. A study of 22 cases

Twenty-two cases of epithelial-myoepithelial carcinoma of major and minor salivary glands were studied retrospectively to define the clinico-pathological profile and to assess the value of DNA ploidy as a prognostic tool. Fifty-nine percent of the cases occurred in the major salivary glands, the patients being mostly females in their 5th to 8th decades. The clinical course was characterized by a high number of recurrences (in 50% of cases). Death due to the neoplastic disease was found in 40% of the patients. The only morphological feature found to be correlated to prognosis was the presence of nuclear atypia in more than 20% of the tumour cells. In 18 cases, cytophotometric DNA analysis was performed; 15 cases had a diploid DNA histogram and 3 an aneuploid one. All the cases that were DNA aneuploid were of the solid, predominantly clear-cell type and were associated with fatal outcome.

Epithelial-myoepithelial carcinoma of salivary gland with metastasis to lung: report of a case and review of the literature

A 63-year-old man was initially seen with multiple pulmonary nodules 14 years after a left parotidectomy for an epithelial-myoepithelial carcinoma of salivary gland. Eight and 18 months after parotidectomy, the patient had local recurrence of his salivary gland tumor. He remained disease-free before being seen with pulmonary nodules, which were evaluated by open lung biopsy. The pathologic features of the pulmonary nodules were identical to the salivary gland tumor resected 14 years earlier. This is the fourth reported case of epithelial-myoepithelial carcinoma of salivary gland metastasizing to a distant site.

The World Health Organization's Histological Classification of Salivary Gland Tumors. A commentary on the second edition

The second edition of the World Health Organization's Histological Classification of Salivary Gland Tumors is more extensive and detailed than the previous edition published 20 years ago. The new edition is based on data regarding newly described tumor entities and the behavior and prognosis of the previously classified tumors. The distinct morphologic features of monomorphic adenomas justify their separation for purposes of identification. Among the carcinomas, various types were distinguished for purposes of recognition, prognosis, and treatment. The term tumor was replaced by carcinoma in the following two entities: acinic cell carcinoma and mucoepidermoid carcinoma. The tumor-like lesions were described in more detail.

Histopathology of malignant salivary gland tumours

This report is based upon the Salivary Gland Register in Hamburg and on the second revised edition of the WHO Histological Typing of Salivary Gland Tumours. The group of malignant salivary gland tumours contains carcinomas, malignant non-epithelial tumours, malignant lymphomas and secondary tumours. The various carcinomas are classified in a continuous separate listing because the different types are distinguished not only by histopathology, but also by differences in prognosis and treatment. The term "tumour" is replaced by "carcinoma" in two entities: acinic cell carcinoma and mucoepidermoid carcinoma. New entities are: polymorphous low-grade adenocarcinoma, basal cell adenocarcinoma, salivary duct carcinoma and malignant myoepithelioma. Carcinoma in pleomorphic adenoma can be distinguished as non-invasive and invasive carcinoma, and carcinosarcoma. Malignant non-epithelial tumours are mostly malignant fibrous histiocytoma, malignant schwannoma and rhabdomyosarcoma. The large majority of malignant lymphomas are non-Hodgkin-lymphomas with high differentiation. Many lymphomas are associated with chronic immunosialadenitis (Sjögren's syndrome). Secondary tumours are mostly metastases from primary squamous cell carcinomas or from melanomas of the skin (head and neck area). Haematogeneous metastases are very rare (mainly from lung, kidney or breast).

Epithelial-myoepithelial carcinoma of salivary glands

Epithelial-myoepithelial carcinomas comprise approximately 1% of all salivary gland neoplasms. They are preponderantly tumors of the parotid glands with a relatively low mortality but a decided locoregional aggressiveness. Histopathologically, the carcinomas are characterized by a dual cell population of epithelial (ductal) cells and myoepithelial cells. These cells vary in their dominance and phenotypic expression.

Troublesome tumours 2: borderline tumours of salivary glands

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Epithelial-myoepithelial carcinoma of the parotid gland in a child

A rare case of epithelial-myoepithelial carcinoma of the parotid gland, which occurred in a child, is reported. An 8-year-old boy presented with swelling of the right parotid gland. He underwent total parotidectomy followed by irradiation for a parotid gland tumor. Three years after the operation, a recurrent tumor invading the base of the skull and the brain and metastases in the lung were noted. The patient expired in spite of extirpation of the intracranial recurrent tumor. The resected tumor showed a characteristic histologic feature: double-layered tubular structures composed of inner dark cells (epithelial cells) and outer clear cells (myoepithelial cells). This patient may be the youngest one with the epithelial-myoepithelial carcinoma reported in the literature.

Epithelial salivary gland tumors of children and adolescents in southern Portugal. A clinicopathologic study of twenty-four cases

During a 30-year period 24 epithelial salivary gland tumors were diagnosed in children and adolescents less than 18 years of age. The cases were retrieved from a series of 759 consecutive cases of salivary gland tumors (3.2%) from the area corresponding to southern Portugal during the same period of time. The mean age of the patients was 13.4 years, and one case was congenital. There was a slight female predominance (male/female ratio 1:1.7). The parotid gland was affected in most cases (70.8%). Seventeen neoplasms were benign, and the remaining seven were malignant. As in the adult group, pleomorphic adenoma was the most frequent benign tumor (66.6%), with similar histologic findings and clinical course. Mucoepidermoid carcinoma was the prevalent malignant tumor (20.8%), had a high grade of differentiation, and had a favorable outcome. The histologic pattern of the congenital neoplasm was similar to that of adult epithelial-myoepithelial carcinoma.

Epithelial-myoepithelial carcinoma of salivary glands

Four cases of epithelial-myoepithelial carcinoma of the salivary glands arose as painless masses in patients over 60 years old, three in the parotid and one in the submandibular gland. Histologically, all the tumours were composed of small ducts with a double cell lining surrounded by a basement membrane. The inner cells were epithelial and the outer cells myoepithelial, the latter usually possessing clear cytoplasm. There was a variable degree of intervening hyalinised stroma. All the tumours were partly encapsulated, but also displayed local invasiveness. One of the tumours also showed areas of dedifferentiation when it later recurred and metastasised. The other three were apparently cured by initial excision, with adjuvant radiotherapy in one instance. In the past this tumour has been described as clear cell adenoma, and it was only recently that its true malignant nature, albeit low grade, was recognised. Reports of epithelial-myoepithelial carcinoma are still relatively few, with only one case described from Britain. It is recommended that this histologically distinct neoplasm deserves wider recognition.

WHO International Histological Classification of Tumours. Tentative Histological Classification of Salivary Gland Tumours

The principles of the proposed modified WHO Histological Typing of Salivary Gland Tumours are based on the following: 1) The classification of tumours is oriented to the routine work of the practicing surgical pathologists, those who do not see tumours of the salivary glands very often. The inclusion of rare, but clearly defined tumour entities should be helpful to surgical pathologists consulting with clinical specialists. 2) The different types of carcinomas must be distinguished not only by precise histopathological definitions, but also considering differences in prognosis and treatment. For example, the polymorphous low-grade adenocarcinoma and the epithelial-myoepithelial carcinoma are characterized by a relatively good prognosis in contrast to the salivary duct carcinoma. 3) Special points of discussion are: subclassification and grading of carcinomas (e.g. acinic cell carcinoma, mucoepidermoid carcinoma and adenoid cystic carcinoma), the classification of basal cell tumours (basal cell adenoma, basal cell carcinoma, solid type of adenoid cystic carcinoma), malignant tumours in pleomorphic adenomas and the differential diagnosis between primary tumours and metastases.

Prognosis of salivary adenocarcinomas. A retrospective study of 52 cases with special regard to cytochemically assessed nuclear DNA content

52 salivary adenocarcinomas of the years 1965-1980 from the files of the Salivary Gland Registry, Institute of Pathology, University of Hamburg, were evaluated retrospectively with regard to clinical follow up and cytochemically assessed nuclear DNA content. The age distribution showed a peak from the 6th to 8th decade (range 3 to 87 years). The m:f ratio was 1:1.36, the mean age was 59.3 years. Over 80% of the tumours were located in the major salivary glands. The clinical course was characterized by metastases present at initial diagnosis (16 cases), subsequent development of metastases (9 cases), local recurrence (15 cases) or death from tumour (10 cases) and was related to differentiation, grade 3 tumours showing the worse clinical courses. In 37 cases, nuclear DNA content was determined by a single scanning cytophotometry device. 28 cases were diploid, 9 were atypical. The clinical course was significantly related to the histogram type, atypical tumours showing a dismal prognosis.