Background

Epithelial–myoepithelial carcinomas are well recognized but rare neoplasms that occur most commonly in the salivary glands, where they constitute only 1% of primary tumors. At this site they show a spectrum of morphologic features ranging from a purely myoepithelial phenotype to tumors containing both well-formed glandular elements and myoepithelial cells, these sometimes being termed adenomyoepitheliomas. They show a spectrum of biologic activity ranging from benign lesions to highly aggressive carcinomas. Epithelial–myoepithelial carcinomas are also very rarely seen in other organs containing salivary-type seromucinous glands, including breast, sweat glands, and bronchi.

Outline

Epidemiology
Disease Associations
Pathogenesis
Gross Appearance and Clinical Variants
Histopathological Features and Variants
Special Stains/Immunohistochemistry/Electron Microscopy
Differential Diagnosis
Prognosis and Treatment
Commonly Used Terms
Internet Links

EPIDEMIOLOGY	CHARACTERIZATION
INCIDENCE	Rare 1% of salivary gland tumors
AGE	7th decade
SEX	Slight female predominance

 

DISEASE ASSOCIATIONS

CHARACTERIZATION

Epithelial-myoepithelial carcinoma arising in pleomorphic adenoma of the palate. Li CY, Shirasuna K, Ishibashi H, Nakayama H, Kiyoshima T. Kyushu University, Oral and Maxillofacial Surgery, Fukuoka, Japan.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000 Oct;90(4):460-5 Abstract quote A case of epithelial-myoepithelial carcinoma (EMC) in pleomorphic adenoma (PA) occurring in the palate of a 72-year-old woman is reported. The tumor was composed of 2 different components, PA and EMC, accounting for approximately 40% and 60% of the whole tumor, respectively. The EMC showed multiple tubular or solid nests, which were separated by a basement membrane and consisted of variable proportions of 2 cell types, cuboidal epithelial cells positive for cytokeratin and clear myoepithelial cells positive for glial fibrillary acid protein, whereas the myoepithelial nests of PA intermingled with hyaline and myxoid stroma. The malignancy was demonstrated by convincing evidence of invasion into the submucosa, although the EMC component was mostly surrounded by the PA components. An increased immunoreactivity of proliferating cell nuclear antigen in the EMC area in comparison to the PA area also suggested EMC arising in a PA.

 

PATHOGENESIS	CHARACTERIZATION
Intercalated duct hyperplasia: possible relationship to epithelial-myoepithelial carcinoma and hybrid tumours of salivary gland. Chetty R. Division of Anatomical Pathology, University of Natal School of Pathology and Laboratory Medicine, Durban, South Africa.	Histopathology 2000 Sep;37(3):260-3 Abstract quote AIMS: The aims of this study were to ascertain the incidence of intercalated duct hyperplasia in association with cases of epithelial-myoepithelial carcinoma (EMC), and to explore a possible relationship between them and hybrid carcinomas of salivary glands. METHODS AND RESULTS: Seven cases of EMC with sufficient surrounding non-tumour parotid were examined. Three cases contained foci of intercalated duct hyperplasia adjacent to the tumour. One of the cases was a hybrid tumour composed of EMC and mucoepidermoid carcinoma. The hyperplastic intercalated ducts formed multiple foci within the salivary parenchyma and were composed of bland, uniform ducts. Cytological atypia was not identified. CONCLUSIONS: Intercalated duct hyperplasia may be a precursor lesion to EMC. Furthermore, it may also explain why EMC is frequently associated with other salivary gland carcinomas, so-called hybrid tumours, as well as sharing histological features with adenoid cystic carcinoma. Recognition of the latter is of particular importance because adenoid cystic carcinoma carries a poor prognosis.
Epithelial-myoepithelial carcinoma harboring p53 mutation. Daa T, Kashima K, Gamachi A, Nakayama I, Yokoyama S. 1st Department of Pathology, Oita Medical University, Japan.	APMIS 2001 Apr;109(4):316-20 Abstract quote A case of epithelial-myoepithelial carcinoma of the parotid gland harboring p53 mutation is reported. The tumor removed from a 67-year-old Japanese female was composed of an organoid biphasic population of cells: inner dark epithelial cells were surrounded by clear myoepithelial cells. The cells were immunopositive for EMA and smooth muscle actin, respectively. Some of the epithelial cells formed solid nests. Immunostaining for proliferating cell nuclear antigen (PCNA) resulted in a higher percentage of labeled cells in the solid epithelial region than in the region with the more general biphasic pattern. Genetic analysis, including polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and nucleotide sequencing, revealed a mutation in codon 207 (aspartic acid to glycine) of the p53 tumor-suppressor gene. To our knowledge, this is the first report of a mutation in the p53 gene in an epithelial-myoepithelial carcinoma of the salivary gland.

 

GROSS APPEARANCE/ CLINICAL VARIANTS	CHARACTERIZATION
GENERAL
VARIANTS
Epithelial-myoepithelial carcinoma of the lung: immunohistochemical and ultrastructural observations and review of the literature. Wilson RW, Moran CA. Department of Pulmonary and Mediastinal Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.	Hum Pathol 1997 May;28(5):631-5 Abstract quote Epithelial-myoepithelial carcinoma is a rare low-grade malignant salivary gland neoplasm that most commonly occurs in the parotid gland but can also arise in minor salivary glands. We report a case of a primary epithelial-myoepithelial carcinoma of the lung. The patient is a 55-year-old black woman who presented with increasing shortness of breath and productive cough of at least 3 months duration. A left lower lobe endobronchial lesion was identified radiographically. Surgical resection of the lesion was performed, obtaining a circumscribed, nonencapsulated 3.9 cm tan mass which was attached to the inner wall of the lateral basal segment bronchus. A biphasic proliferation of epithelial (cytokeratin positive; S-100 protein and muscle-specific actin negative) and myoepithelial (S-100 protein and muscle-specific actin positive with focal weak cytokeratin positive) cells was identified by immunohistochemical and ultrastructural analysis of formalin-fixed tissue. The patient is disease free 7 months after resection. Pulmonary epithelial-myoepithelial carcinoma likely derives from the submucosal bronchial glands and should be added to the growing list of salivary gland-type neoplasms that may occur as primary pulmonary neoplasms. Because its histology is identical to salivary epithelial-myoepithelial carcinoma, pulmonary epithelial-myoepithelial carcinoma should be considered a low-grade malignant neoplasm and should be designated as epithelial-myoepithelial carcinoma is preference to other terms that may not convey its malignant potential. Although follow-up on reported cases is limited, lobectomy with negative bronchial margin should be curative.
Epithelial-myoepithelial carcinoma arising in the nasal cavity: a case report and review of literature. Jin XL, Ding CN, Chu Q. Department of Pathology, Rul Jin Hospital, Shanghai Second Medical University, China.	Pathology 1999 May;31(2):148-51 Abstract quote Epithelial-myoepithelial carcinoma is an uncommon, low-grade, malignant epithelial neoplasm composed of variable proportions of ductular cells and large, clear staining, myoepithelial cells arranged around the periphery of the ducts. About 120 cases have been reported in the world literature, most of which were located in salivary glands, except for a few cases occurring in unusual locations such as breast, lacrimal gland, nose, paranasal sinus, trachea, bronchus, and lung. We here reported the second case of epithelial-myoepithelial carcinoma of the nasal cavity with extension to the nasopharynx. The patient was a 61 year old Chinese female with two month's history of progressive nasal obstruction. Histopathologically, the tumor showed typical myoepithelial and ductal cells biphasic differentiation, duct-like structure and infiltrating growth pattern. Some ductal cells showed the characteristics of oxyphilic cell, which had never been reported before. Recurrence and metastasis rates of epithelial-myoepithelial carcinoma varied from 35% to 50% and 8.1% to 25% respectively in different reports. The present case had neither recurrence nor metastasis twenty months after operation. When epithelial-myoepithelial carcinoma is mainly composed of spindle myoepithelial cells, the differential diagnosis should include myoepithelioma, neurofibroma, leiomyoma and hemangiopericytoma.
Epithelial-myoepithelial carcinoma of the nasal cavity. Lee HM, Kim AR, Lee SH. Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul.	Eur Arch Otorhinolaryngol 2000;257(7):376-8 Abstract quote A 22-year-old male presented with a 1-year history of nasal obstruction due to a polypoid mass in the right nasal cavity. Histopathologic examination revealed the tumor to consist of a mixture of a trabecular structure with a double-layered arrangement of inner dark cells and outer clear cells. Immunohistochemical examination showed the clear cells to be positive for alpha-smooth muscle actin and S-100 protein. Ultrastructural examination confirmed the myoepithelial cell origin. The tumor was excised and no recurrence or metastasis was found 40 months after surgery. We describe here a rare case of epithelial-myoepithelial carcinoma arising from the nasal cavity, one of the most unusual locations.
Pulmonary epithelial-myoepithelial tumor of unproven malignant potential: report of a case and review of the literature. Pelosi G, Fraggetta F, Maffini F, Solli P, Cavallon A, Viale G. Department of Pathology and Laboratory Medicine, European Institute of Oncology and University of Milan School of Medicine, Italy.	Mod Pathol 2001 May;14(5):521-6 Abstract quote Epithelial-myoepithelial tumors of the lung are rare neoplasms whose biological behavior and clinical course still remain to be defined. A case of epithelial-myoepithelial tumor of the lung arising from bronchial mucosa-submucosa and occurring as a polypoid lesion of the upper left bronchus in a 47-year-old man is reported. The tumor did not infiltrate the cartilaginous wall of the bronchus and showed a biphasic histological appearance with a double layering of epithelial and myoepithelial cells. Myoepithelial spindle cells with eosinophilic cytoplasm were also observed. Mitotic figures were very rare and necrosis absent. Immunohistochemical study for epithelial and muscular markers confirmed the presence of a double-cell component in the tumor, namely epithelial and myoepithelial. The patient is alive and well, with no evidence of recurrent or metastatic disease 6 months after surgery. On the basis of the present case and the six previously reported cases, we suggest using the noncommittal term pulmonary epithelial-myoepithelial tumor of unproven malignant potential (PEMTUMP) for this type of neoplasm. In addition, we first introduce p63 as a novel marker for highlighting the myoepithelial cells of the respiratory tract and speculate on the role of these cells in the development of this unusual tumor.
Epithelial–Myoepithelial Carcinomas of the Bronchus Laura G. Fulford, M.B.B.S. ; Yoshimasa Kamata, M.D. ; Koichi Okudera, M.D. ; Allan Dawson, F.R.C.Path. ; Bryan Corrin, F.R.C.Path. ; Mary N. Sheppard, F.R.C.Path. ; Nassif B. N. Ibrahim, F.R.C.Path. ; Andrew G. Nicholson, D.M. From the Department of Histopathology (L.G.F., B.C., M.N.S., A.G.N.), Royal Brompton Hospital, London, U.K.; the Pathology Center (Y.K.) and Second Department of Internal Medicine (K.O.), Hirosaki University School of Medicine, Hirosaki, Japan; the Department of Histopathology (A.D.), Morriston Hospital, Swansea, U.K.; and the Department of Histopathology (N.B.N.I.), Frenchay Hospital, Bristol, U.K.	Am J Surg Pathol 2001;25:1508-1514 Abstract quote Epithelial–myoepithelial carcinomas are very rare in the lung, and little is known about the relationship of their histologic features to prognosis. We describe five primary pulmonary epithelial–myoepithelial carcinomas with details on clinical presentation, histology, and immunohistochemical profiles. We also reviewed the literature to detail further their prognosis. The patients' ages ranged from 33 to 57 years (average 51 years). The tumors were all endobronchial and the patients presented with symptoms or imaging features of airway obstruction. The tumors were completely resected; none showed nodal involvement. All five patients are alive and free of disease 4 months to 8 years (average 4.2 years) after surgery. Four tumors showed a mixed pattern of glands lined by a dual layer of cells and solid sheets of either spindle cells or clear cells, the glandular and solid components being present in variable proportions. The fifth tumor comprised purely spindle cells. The mitotic rate was <1/20 high power fields in both the glandular and spindle/clear cell components. In one case there was focal nuclear pleomorphism. The inner layer of the glands stained for cytokeratins and epithelial membrane antigen, and the outer layer for S-100 and smooth muscle actin. In one case the spindle cells stained for CD34. A review of published cases shows the majority of tumors behave in an indolent fashion, the rare aggressive tumors being predominantly myoepitheliomatous. Nevertheless, the term epithelial–myoepithelial carcinoma is preferred because of their malignant potential. A high mitotic rate, tumoral necrosis, and nuclear pleomorphism appear to be adverse prognostic factors.

 

HISTOLOGICAL TYPES	CHARACTERIZATION
GENERAL	Double cell proliferation with inner layer of neoplastic ductal cells associated with an outer layer of prominent clear neoplastic myoepithelial cells Infiltrative margins and perineural invasion May have sclerotic hyalinizing variant and clear cell dominant variant which is ductal poor Occasional cases with dedifferentiation
VARIANTS
Epithelial-myoepithelial carcinoma of the parotid. A case of ductal-predominant presentation with cytologic, histologic and ultrastructural correlations. Yang GC, Soslow RA. Department of Pathology, New York University Medical Center, New York 10016, USA.	Acta Cytol 1999 Nov-Dec;43(6):1113-8 Abstract quote BACKGROUND: The cytologic features of the usual type of epithelial-myoepithelial carcinoma (EMC) of the parotid, with myoepithelial cell predominance, is well described in the cytology literature. In contrast, the cytologic features of ductal-predominant-type EMC has not yet been reported. CASE: An 82-year-old male presented with a 2.7-cm parotid mass of two years' duration. Fine needle aspiration smears stained with Diff-Quik showed cohesive tissue fragments outlined by metachromatic fibrils scattered in abundant, smooth, bluish background material. Ultrafast Papanicolaou stain revealed sharply outlined, large ductal cells with smooth, round to oval nuclei, prominent nucleoli and abundant vacuolated cytoplasm; the cells were arranged tridimensionally in occasional follicles that contained thick secretions. Neoplastic myoepithelial cells were occasionally seen at the periphery of tissue fragments, most commonly hidden underneath the neoplastic ductal epithelium at a slightly different focal plane; the cells had small, oval, dark nuclei and inconspicuous cell borders. The nuclear area and cell size of the neoplastic ductal cells was two and three times, respectively, that of neoplastic myoepithelial cells. CONCLUSION: EMC, depending on the ratio of ductal to myoepithelial cell components, has different cytologic presentations. This case illustrates the ductal-predominant presentation of EMC.
High-grade carcinoma component in epithelial-myoepithelial carcinoma of salivary glands clinicopathological, immunohistochemical and flow-cytometric study of three cases. Alos L, Carrillo R, Ramos J, Baez JM, Mallofre C, Fernandez PL, Cardesa A. Department of Pathology, Hospital Clinic and IDIBAPS, University of Barcelona, Spain.	Virchows Arch 1999 Apr;434(4):291-9 Abstract quote Three cases of epithelial-myoepithelial carcinoma (EMC) with coexisting areas of high grade carcinoma are reported. In two of the cases there was a previous recurrence, and in all three patients there had been a sudden increase in size before final surgery. T he typical ductal and myoepithelial components of EMC showed the usual biphasic pattern and the expected immunophenotypes, with expression of wide spectrum cytokeratins, Cam 5.2 and EMA in the ductal part, and muscle-specific actin, smooth muscle actin, S-100 protein, vimentin and cytokeratins in the myoepithelial component. These areas also had a low mitotic count and low proliferation rate as measured by immunohistochemistry and by flow cytometry. Conversely, areas of high-grade tumour had the features of a large cell carcinoma, with focal mucin secretion in two cases. This high-grade component showed an epithelial immunophenotype in two cases, and was negative for all tested markers in the third one. The mitotic counts and the proliferation rates were much higher in these anaplastic areas. One of the patients died 3 months after treatment; another developed lymph node metastases 1 year later and was alive after 6 years of follow-up. The third patient was alive without evidence of disease 7 months after wide surgical resection of the tumour. The possibility of anaplastic transformation in EMC makes thorough sampling mandatory in this type of neoplasm.

 

SPECIAL STAINS/IMMUNOPEROXIDASE/ OTHER	CHARACTERIZATION
SPECIAL STAINS
IMMUNOPEROXIDASE
Epithelial-myoepithelial carcinoma: an immunocytochemical study. Palmer RM.	Oral Surg Oral Med Oral Pathol 1985 May;59(5):511-5 Abstract quote An immunocytochemical study of epithelial-myoepithelial carcinoma, using antibodies to smooth muscle myosin, keratins, and type IV collagen, is presented. This rare tumor of salivary gland is composed of tubules and ductal structures, comprising an outer layer of clear cells that show myoepithelial differentiation and an inner layer of eosinophilic cells that show ductal differentiation. The findings in this study correlate well with previous ultrastructural descriptions of this tumor.
Epithelial-myoepithelial carcinoma of parotid gland: a case report with immunohistochemical and ultrastructural studies. Shuangshoti S, Lutigaviboon V, Kasantikul V. Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.	J Med Assoc Thai 1998 Sep;81(9):712-6 Abstract quote A 66-year-old man presented with a painless mass of the parotid gland. Light and electron microscopic studies verified the basic nature of the tumor as epithelial-myoepithelial carcinoma, a low-grade malignant neoplasm of the salivary gland. Pathologically, there were two types of cells; the inner eosinophilic epithelial cells lining the ducts and the outer clear cells. The former cells displayed immunoreactivity for cytokeratin and ultrastructural features of apical microvilli and desmosome. The latter cells were positive for actin, S-100 protein, vimentin and the cytoplasm contained actin microfilaments. Such pathological findings were characteristic features of this rare tumor. To our knowledge, this is the first reported case of EMC in Thailand.
The myoepithelial immunophenotype in 135 benign and malignant salivary gland tumors other than pleomorphic adenoma. Prasad AR, Savera AT, Gown AM, Zarbo RJ. Henry Ford Hospital, Detroit, MI 48202, USA.	Arch Pathol Lab Med 1999 Sep;123(9):801-6 Abstact quote BACKGROUND: We have previously studied the immunoreactivity of 3 novel smooth muscle-specific proteins, alpha-smooth muscle actin, smooth muscle myosin heavy chains, and calponin, to assess myoepithelial differentiation in pleomorphic adenomas. OBJECTIVE: To further expand our knowledge of myoepithelial differentiation in other benign and malignant salivary gland tumors. DESIGN: Formalin-fixed paraffin sections of 135 salivary gland tumors with associated normal glands were stained with monoclonal antibodies using the avidin-biotin complex immunoperoxidase method and enzymatic and microwave heat-induced epitope retrieval. RESULTS: In adenoid cystic carcinomas and epithelial-myoepithelial carcinomas, all 3 markers exclusively highlighted the myoepithelial cell components and the epithelial cells were entirely negative. No immunostaining was detected in canalicular adenomas, oncocytomas, Warthin tumors, acinic cell carcinomas, mucoepidermoid carcinomas, squamous cell carcinomas, and polymorphous low-grade adenocarcinomas. Salivary duct carcinomas and adenocarcinomas, not otherwise specified had a distinctive pattern of uniform periductal staining of reactive myofibroblastic cells, and in salivary duct carcinomas some ducts retained a peripheral immunoreactive myoepithelial cell layer. CONCLUSION: Immunoreactivity for these 3 smooth muscle-specific proteins confirms the known neoplastic myoepithelial component of adenoid cystic carcinomas and epithelial-myoepithelial carcinomas. The consistently positive staining pattern in adenoid cystic carcinomas may be diagnostically useful in discriminating histologically similar but consistently negative polymorphous low-grade adenocarcinomas. Periductal linear staining in adenocarcinoma, not otherwise specified and salivary duct carcinomas is distinctive and appears to represent a tight cuff of myofibroblasts associated with the infiltrating glands.

 

DIFFERENTIAL DIAGNOSIS	KEY DIFFERENTIATING FEATURES
Adenoid cystic carcinoma
Basal cell carcinoma
Low grade polymorphous adenocarcinoma

 

PROGNOSIS AND TREATMENT	CHARACTERIZATION
PROGNOSTIC FACTORS	Oral Surg Oral Med Oral Pathol 1985;59:482-490 Virch Arch A Pathol Anat 1993;422:389-396 Thought to be a low to intermediate grade malignancy with 39% recurrence rate and 8.5% death rate in one series of 9 cases Another series with 20 cases found cumulative survival of 87.1% at 5 years and 67.5% at 10 years with a 41% recurrence rate, 35% metastatic rate, and 40% rate of death from disease indicating long term follow up is needed
Epithelial-myoepithelial duct carcinoma of salivary glands: a follow-up and cytophotometric study of 21 cases. Hamper K, Brugmann M, Koppermann R, Caselitz J, Arps H, Askensten U, Auer G, Seifert G. Institute of Pathology, University-Hospital Hamburg-Eppendorf, West Germany.	J Oral Pathol Med 1989 May;18(5):299-304 Abstract quote The Salivary Gland Registry provided 21 cases of epithelial-myoepithelial duct carcinoma of salivary glands from 1965-1980 which were evaluated retrospectively for clinical follow-up and cytophotometric data; 81% were localized in the major, 19% in the minor salivary glands. The male:female ratio was 1:1.1, 10 patients (47.6%) being men and 11 (52.4%) women. The youngest patient was 27, the oldest 91 y old. The mean age was 59.3 y (overall), 57.9 y (women) and 61.0 (men). The clinical course was characterized by lymph node metastases present at initial diagnosis and local recurrences in 23.5%. No patient died of the tumor. In 12 cases, cytochemical assessment of nuclear DNA by means of single cell scanning cytophotometry yielded diploid histograms. According to clinical and cytophotometrical data, epithelial-myoepithelial duct carcinoma of salivary glands can be regarded as a proper tumor entity of low grade malignancy.
Epithelial-myoepithelial carcinoma of the parotid gland: a clinico-pathologic and immunohistochemical study of seven cases. Collina G, Gale N, Visona A, Betts CM, Cenacchi V, Eusebi V. Istituto di Anatomia e Istologia Patologica, Universita di Bologna, Italy.	Tumori 1991 Jun 30;77(3):257-63 Abstract quote Seven cases of epithelial-myoepithelial carcinoma of the parotid gland are reported. Immunohistochemical evidence for the dual (glandular secretory and myoepithelial) differentiation of the cells composing these lesions is presented. Three of the cases recurred locally and two gave rise to metastases. The biologic behavior does not appear to be correlated with the histologic features that constitute the morphologic spectrum of epithelial-myoepithelial carcinoma.
Epithelial-myoepithelial carcinoma of salivary gland with metastasis to lung: report of a case and review of the literature. Noel S, Brozna JP. Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha.	Head Neck 1992 Sep-Oct;14(5):401-6 Abstract quote 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.
Proliferating cell nuclear antigen immunohistochemistry in epithelial-myoepithelial carcinoma of the salivary glands. Fonseca I, Soares J. Department of Pathology, Portuguese Cancer Institute, Lisbon.	Arch Pathol Lab Med 1993 Oct;117(10):993-5 Abstract quote Myoepithelial-type cells are largely predominant in the composition of aggressive recurrent epithelial-myoepithelial carcinoma, suggesting that such tumor cell lineage constitutes a highly proliferating neoplastic population. Thirteen cases of epithelial-myoepithelial carcinoma, seven of the solid type and six of the tubular-cribriform type, were immunostained with the anti-proliferating cell nuclear antigen PC10 antibody to evaluate the proliferative activity of the two tumor cell components. Positively stained nuclei were only observed in the myoepithelial cells. Only one of the 13 cases, of tubular architectural type, had a few but unequivocally positive ductlike cells. The percentage of cycling clear cells varied between 0.2% and 45.7%. Higher values were observed in the solid (11.2% to 45.7%) as compared with tubular-cribriform epithelial-myoepithelial carcinoma (0.2% to 6.3%) and were associated with a high recurrence rate of the neoplasm. No other relationship was found between proliferating cell nuclear antigen indexes and clinical evolution. T hese results point to epithelial-myoepithelial carcinoma growth being related to the proliferation of the myoepithelial cell component. The proliferating role of the duct cell population seems to be irrelevant, which points to these neoplastic cells being a "terminally differentiated" component with low potential dividing capacity.
Epithelial-myoepithelial carcinoma of the salivary glands. A study of 22 cases. Fonseca I, Soares J. Servico de Patologia Morfologica, Instituto Portugues de Oncologia de Francisco Gentil, Lisboa.	Virchows Arch A Pathol Anat Histopathol 1993;422(5):389-96 Abstract quote 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 glands. A clinicopathologic, DNA flow cytometric, and immunohistochemical study of Ki-67 and HER-2/neu oncogene. Cho KJ, el-Naggar AK, Ordonez NG, Luna MA, Austin J, Batsakis JG. Department of Pathology, University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA.	Am J Clin Pathol 1995 Apr;103(4):432-7 Abstract quote Thirty-one salivary gland epithelial-myoepithelial carcinomas from 26 patients were studied by DNA flow cytometry, and immunostaining for Ki-67 and HER-2/neu oncogene product. The results were correlated with clinicopathologic factors and patient outcome. The tumor most commonly involved the parotid gland, and mainly affected patients in their 6th to 8th decades. The clinical course was characterized by a high incidence of local recurrence (50%) and not infrequent distant metastasis (25%). None of the patients in this cohort died of disease. DNA content analysis revealed 21 neoplasms with DNA diploidy and 5 tumors with DNA aneuploidy; all aneuploid cases were near-diploid (hyperdiploidy) and showed low proliferative activity. All aneuploid and 60% of the diploid neoplasms developed recurrences and/or metastases. Immunohistochemical analysis of Ki-67 proliferation markers also showed low overall growth fractions. Interestingly, Ki-67 immunoreactivity was largely restricted to myoepithelial cells, suggesting a central role for this cell in the development of these tumors. HER-2/neu oncogene analysis failed to demonstrate overexpression in any of the tumors examined. This study indicates that epithelial-myoepithelial carcinoma is a low grade malignant neoplasm with a high propensity for recurrence. HER-2/neu oncogene and Ki-67 offer no additional advantages over current factors in the biologic evaluation of these neoplasms. DNA aneuploidy may allow for the identification of a subset of tumors that is more prone to recurrence and metastasis, but further studies with extended follow-up are needed.
Cell proliferation in salivary gland adenocarcinomas with myoepithelial participation. A study of 78 cases. Fonseca I, Felix A, Soares J. Departamento de Patologia Morfologica & Centro de Investigacao de Patobiologia Molecular (CIPM), Instituto Portugues de Oncologia de Francisco Gentil, Lisboa, Portugal.	Virchows Arch 1997 Mar;430(3):227-32 Abstract quote We used three markers of cell proliferation mitotic counts, mitotic index and expression of proliferating cell nuclear antigen--to assess the proliferative activity of a series of 78 low-grade salivary adenocarcinomas with myoepithelial participation classified according to: their histological type, the predominant architectural type, and the predominant cytological type. The series included adenoid cystic carcinomas (40), epithelial-myoepithelial carcinomas (19), polymorphous low-grade adenocarcinomas (12) and basal cell adenocarcinomas (7). The proliferation indicators were found to be similar in the first three groups, being significantly lower than in the last. Tumours formed by basal cells had statistically significant higher mitotic indexes than those predominantly composed of clear cells of myoepithelial type and ductal cells. Tubular tumours, irrespective of the histological classification of the neoplasm, had proliferation indexes similar to those found in cribriform neoplasms. Solid tumours, whether formed by ductal or clear myoepithelial-type cells, had higher indexes than the neoplasms with differentiated (cribriform and tubular) patterns. The highest mean values for every proliferation indicator used were found in tumours with solid organization that were predominantly formed by basal cells. These results agree with the hypothesis that cell proliferation is inversely related to neoplastic differentiation. The identification of the prevalent cell phenotype and architecture may extend our knowledge from adenoid cystic carcinoma, whose solid variant carries a worse prognosis, and supports that the usual classification of this group of salivary adenocarcinomas would benefit to be complemented with information on tumour architecture and cellular composition.
Epithelial-myoepithelial carcinoma of the salivary glands: a clinico-pathologic, immunohistochemical and DNA flow cytometric study of three cases. Tralongo V, Rodolico V, Nagar C, Mancuso A, Salvato M, Daniele E. Istituto di Anatomia ed Istologia Patologica, University of Palermo, Italy.	Anticancer Res 1997 Jan-Feb;17(1B):761-8 Abstract quote Epithelial-myoepithelial carcinoma is a rare neoplasia of the salivary glands. Histologic, immunohistochemical and flow cytometry analysis were used to study three new cases involving the major salivary glands of two women and one man. The mean age was 66.7 years. Immunohistochemistry confirmed the epithelial-myoepithelial dualism of the tumors: the predominant growth pattern showed ducts made up of an external myoepithelial layer and an internal epithelial layer. Proliferative activity, assessed by means of the PCNA and Ki-67 immunostaining and the study of the S-phase with flow cytometric analysis, proved to be higher in a recurrent case. All three cases were diploid. The use of immunohistochemical and flow cytometric techniques for the assessment of proliferative activity would seem to be an efficient method for the selection of a subgroup of epithelial-myoepithelial carcinomas with unfavorable prognosis.
Epithelial-myoepithelial carcinoma of the parotid gland with multiple distant metastases: a case report. Friedrich RE, Donath K. Eppendorf University Hospital, University of Hamburg, Germany.	J Oral Maxillofac Surg 2000 Jun;58(6):690-4
TREATMENT	Surgical Excision

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Salivary Glands

Last Updated 12/5/2001

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