Catalucci, Alessia

Del Nonno, Franca

Di Rocco, Zorika Christiana

Donato, Salvatore

Falzone, Andrea

Licci, Stefano

Morelli, Luca

Neri, Marinella

Piscioli, Irene

English

PubMed

Irene Piscioli

Luca Morelli

Andrea Falzone

Franca Del Nonno

Marinella Neri

Zorika Di Rocco

Alessia Catalucci

Salvatore Donato

Stefano Licci

Crossref

Epithelial-myoepithelial carcinoma of the parotid gland, unusual malignancy radiologically simulating a benign lesion: case report

Springer - Publisher Connector

BioMed Central
International Seminars in Surgical 
Oncology
ssOpen AcceCommentary
Epithelial-myoepithelial carcinoma of the parotid gland, unusual 
malignancy radiologically simulating a benign lesion: case report
Irene Piscioli1, Luca Morelli2, Andrea Falzone3, Franca Del Nonno4, 
Marinella Neri3, Zorika Christiana Di Rocco5, Alessia Catalucci6, 
Salvatore Donato7 and Stefano Licci*4
Address: 1Department of Radiology, Civil Hospital of Budrio, Italy, 2Department of Pathology, "S. Maria del Carmine" Hospital, Rovereto, Italy, 
3Department of Radiology, "S. Maria del Carmine" Hospital, Rovereto, Italy, 4Department of Pathology, National Institute for Infectious Diseases 
"L. Spallanzani" IRCCS, Rome, Italy, 5Department of Oncology, "Istituto Dermopatico dell'Immacolata", Rome, Italy, 6Department of Radiology, 
"S. Salvatore" Hospital, L'aquila, Italy and 7Department of Radiology, Civil Hospital of Bentivoglio, Italy
Email: Irene Piscioli - irenedelirium@libero.it; Luca Morelli - Luca.Morelli@apss.tn.it; Andrea Falzone - Andrea.Falzone@apss.tn.it; Franca Del 
Nonno - delnonno@inmi.it; Marinella Neri - marinellan@hotmail.com; Zorika Christiana Di Rocco - zcdirocco@yahoo.com; 
Alessia Catalucci - alessiacat@tiscali.it; Salvatore Donato - salvatore.donato@ausl.bo.it; Stefano Licci* - licci@inmi.it
* Corresponding author    
Abstract
Background: Ultrasound (US), Computed Tomography (CT) and Magnetic Resonance Imaging
(MRI) are widely used in the clinical diagnosis of parotid gland tumors and their efficacy in identifying
benign lesions is well documented. However, problems arise when facing some malignant lesions.
Only few cases of salivary gland low grade malignant tumors have been previously reported in the
literature complete with the radiological features.
Case presentation: We here describe a case of epithelial-myoepithelial carcinoma (EMC) of the
parotid gland, a low grade malignant tumor, with spread to an intraparotid lymph node and with
CT and MRI findings mimicking a benign lesion.
Conclusion: All the images revealed sharply outlined profiles and a homogeneous enhancement
of the nodule, suggesting a benign tumor and demonstrating that a radiological evaluation of the
lesion alone may be unsatisfactory and misleading in the diagnosis of salivary gland tumours,
especially in the case of low grade malignant tumors, such as EMC.
Background
Nowadays different imaging techniques offer optimal vis-
ualization of the parenchyma and of the tumors of the
parotid gland. Ultrasound (US) imaging is the first-line
technique in the radiological study of parotid lesions
because it is an easy, quick, repeatable and non-invasive
procedure. Moreover, since the parotid gland is superficial
and easily accessible to the ultrasound transducer (even
up to 12 MHz [1]), US is highly sensitive. However, US
can be unsatisfactory in the differential diagnosis of some
tumors and inflammatory diseases and it is not adequate
for all glandular areas. In fact, for tumors situated in the
deep lobe, which is poorly visualized with ultrasound, as
it is obscured by the mandible, it is impossible to evaluate
the lesions.
Published: 16 October 2007
International Seminars in Surgical Oncology 2007, 4:25 doi:10.1186/1477-7800-4-25
Received: 4 July 2007
Accepted: 16 October 2007
This article is available from: http://www.issoonline.com/content/4/1/25
© 2007 Piscioli et al; licensee BioMed Central Ltd. 
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), 
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Page 1 of 4
(page number not for citation purposes)
International Seminars in Surgical Oncology 2007, 4:25 http://www.issoonline.com/content/4/1/25Contrast-enhanced computed tomography (CT) is the
second choice radiological approach: it allows both
assessment of the lesion and adequate exploration of the
deeper gland parenchyma and offers highly defined spa-
tial resolution along with a panoramic overview of the
entire head-neck region.
Magnetic Resonance Imaging (MRI) is mandatory, repre-
senting a valid alternative to CT or a complementary
approach to better assess the lesion. Compared to CT, MRI
offers a much higher contrast resolution, but it is inade-
quate to evaluate the presence of calcifications.
CT and MRI can usually assume the benignancy or malig-
nancy of a focal lesion based on simple elements of radi-
ological findings. Benign lesions are usually small in size,
well circumscribed, and have a regular morphology, as in
the case of pleomorphic adenoma and Warthin's tumour.
The characteristic radiological features of these lesions are
represented by well defined margins, the presence of a
capsule, and by bright signal intensity on T2-weighted MR
images. Intralesional calcifications, easily detected by US
and CT, are another element of benignancy.
Malignant tumors are usually medium to large in size
(over 3 cm in diameter), present undefined margins and a
typical heterogeneous echo pattern because of the fre-
quent presence of necrotic areas. MRI can show multiple
round high signal intensity areas on T2WI or a large very
high signal intensity area on T1WI.
Epithelial-myoepithelial carcinoma (EMC) is extremely
rare compared to other carcinomas, and is considered a
low malignancy neoplasm.
In the present report we describe a case of this unusual
parotid gland neoplasia, radiologically simulating a
benign lesion.
Case presentation
In December 2005, an 81-year-old woman came to the
attention of the othorinolaryngology surgeon complain-
ing of a painless, nodular, firm mass of the left parotid
gland arisen a few months before. The patient underwent
a fine needle aspiration cytology (FNAC) and 3 samples
were sent to Department of Pathology. Although the CT
scans suggested a benign lesion, the finding of atypical
cells indicated a malignant tumor. Thus, the patient
underwent a total parotidectomy with a complete excision
of the lesion.
Axial contrast-enhanced CT scan (Fig. 1a) showed a well-
defined, oval, smooth mass in the depth of the left parotid
gland, confined to the glandular parenchyma, slight
enhancing and localized in proximity to the posterior
facial vein and external carotid artery, with no sign of infil-
tration. The parotid gland displayed a normal morfo-vol-
umetric aspect. Coronal T2-weighted (Fig. 1b), axial T2-
weighted (Fig. 1c) and axial T1-weighted (Fig. 1d) images
showed a well-defined nodular mass with a moderately
high signal intensity in T2-weighted images (Fig. 1b–1c),
and a homogeneous low signal intensity in T1-weighted
images (Fig. 1d).
All the images revealed sharply outlined profiles, suggest-
ing a benign lesion.
Grossly, the parotid gland contained a well circumscribed
gray-white nodule, partially plurinodular in structure,
firm on the cut surface and 2.2 cm in diameter.
Histologically, the tumor was characterized by a biphasic
cell population represented by myoepithelial and ductal
cells. The myoepithelial cells were large, polygonal, with
clear-staining cytoplasm and irregularly shaped nuclei.
The ductal elements were composed of cuboidal cells with
eosinophilic cytoplasm and uniform, round voluminous
a) Axial contrast-enhanced CT scan shows a well-defined, oval, smo th mass in the deep portion f the left parotid gland, confi ed in the glan ular pa enchyma and enhancingFigure 1
a) Axial contrast-enhanced CT scan shows a well-defined, 
oval, smooth mass in the deep portion of the left parotid 
gland, confined in the glandular parenchyma and enhancing. 
The parotid gland displays a normal morfo-volumetric aspect; 
b) Coronal T2-weighted MR image. The mass has a homoge-
neous moderately high signal intensity; c) Axial T2-weighted 
MR image. The lesion shows well-defined nodular mass with 
a moderately high signal intensity; d) Axial T1-weighted 
image of the lesion. It shows a uniform low signal intensity.Page 2 of 4
(page number not for citation purposes)
International Seminars in Surgical Oncology 2007, 4:25 http://www.issoonline.com/content/4/1/25nuclei. The cells appeared to grow in sheets with an orga-
noid pattern. Atypia was mild or absent. Mitotic figure
count was very low. Moreover, spread to an intraparotid
lymph node was observed (Fig. 2). A diagnosis of EMC
was made.
US, CT and MRI are widely used in the diagnosis of
parotid gland tumors. In particular CT and MRI are useful
in the detection of salivary gland tumors and in assessing
their extent [2]. Irregular tumor margins and infiltration
into adjacent structures suggest malignancy. However, as
for other human tumors, only histology can definitively
establish the real nature of a lesion, given that some
malignant tumors may mimic benign lesions at CT and
MRI scans [3-5].
Salivary gland tumors are 12-times more frequent in the
parotid gland than in the submaxillary gland, a difference
that can not be explained only on the basis of gland size.
Most parotid gland lesions are benign (83%) and are
largely represented by mixed-type tumors [6]. CT and MRI
imaging are well characterized for the latter lesions and
have also been described in the following malignant
parotid tumors: carcinosarcoma [7], mucoepidermoid
carcinoma, adenoid cystic carcinoma, carcinoma ex pleo-
morphic adenoma, ductal carcinoma, myoepithelial carci-
noma, sebaceous carcinoma and lymphoma [8-10].
Initially reported by Donath et al. [11], EMC arises pre-
dominantly in the parotid gland, more rarely in the sub-
mandibular and minor salivary glands.
To our knowledge, diagnostic imaging findings of EMC
have been previously reported only few times [12-14].
In the report by Witterick et al. [12], the management of
the lesion appears quite unusual. The right parotid mass
was examined by US imaging in a follow-up period during
which the size remained the same. Tumor resection was
performed after a FNAC revealed malignant cells. Even
though parotid EMC is a low grade carcinoma with a very
slow growth, the absolutely imperceptible tumor enlarge-
ment described in the report seems to be contradicting
with the intrinsic malignant nature of the lesion.
In the report by Silvers et al. [13], a case of EMC is radio-
logically described: CT scan showed a fairly well defined
heterogeneous lesion with smooth margins and slight
enhancement. MR images showed a lesion with interme-
diate T1-weighted signal intensity and a relatively high T2-
weighted signal intensity.
More recently, Tas et al. [14] reported a case of EMC with
MRI showing an irregular and heterogeneous mass, as typ-
ically seen in other more common parotid malignant
tumors.
Conclusion
In our case of parotid EMC all the images revealed sharply
outlined profiles and a slight enhancement of the nodule,
suggesting a benign tumor and demonstrating that a radi-
ological evaluation of the lesion alone may be unsatisfac-
tory and misleading in the diagnosis of salivary gland
tumours, especially in the case of low grade malignant
tumors, such as EMC. A FNAC of the lesion is always rec-
ommendable.
Competing interests
The author(s) declare that they have no competing inter-
ests.
Authors' contributions
AF, MN, AC, SD and IP participated equally in the design
of the paper and in the study of the radiological data. LM,
SL and FDN participated in the study of macroscopic and
microscopic features of the lesion, in the design of the
study and in the drafting of the manuscript. ZCDR was
involved in the drafting of the manuscript. SL revised crit-
Parotid gland with the neoplasia and intraparotid lymph node inv lvement by e n oplastic proliferation (hematoxyli  andeosin, 200×)Figur 2
Parotid gland with the neoplasia and intraparotid lymph node 
involvement by the neoplastic proliferation (hematoxylin and 
eosin, 200×).Page 3 of 4
(page number not for citation purposes)
International Seminars in Surgical Oncology 2007, 4:25 http://www.issoonline.com/content/4/1/25Publish with BioMed Central   and  every 
scientist can read your work free of charge
"BioMed Central will be the most significant development for 
disseminating the results of biomedical research in our lifetime."
Sir Paul Nurse, Cancer Research UK
Your research papers will be:
available free of charge to the entire biomedical community
peer reviewed and published immediately upon acceptance
cited in PubMed and archived on PubMed Central 
yours — you keep the copyright
Submit your manuscript here:
http://www.biomedcentral.com/info/publishing_adv.asp
BioMedcentral
ically the final version of the manuscript. All authors read
and approved the final manuscript.
Acknowledgements
Written consent was obtained from the patient or their relative for publi-
cation of study.
References
1. Gritzmann N, Rettenbacher T, Hollerweger A, Macheiner P, Hubner
E: Sonography of the salivary glands.  Eur Radiol 2003,
13:964-975.
2. Casselman JW, Mancuso AA: Major salivary gland masses: com-
parison of MR imaging and CT.  Radiology 1987, 165:183-189.
3. Bryan RN, Miller RH, Ferreyro RI, Sessions RB: Computed tomog-
raphy of the major salivary glands.  AJR Am J Roentgenol 1982,
139(3):547-554.
4. Rabinov K, Kell T Jr, Gordon PH: CT of the salivary glands.  Radiol
Clin North Am 1984, 22:145-159.
5. Shah GV: MR imaging of the salivary glands.  Magn Reson Imaging
Clin N Am 2002, 10:631-632.
6. Spero RH: Salivary neoplasms. Overview of a 35-year experi-
ence with 2807 patients.  Head Neck Surg 1986, 8:177-184.
7. King AD, Ahuja AT, To EW, Chan EC, Allen PW: Carcinosarcoma
of the parotid gland: ultrasound and computed tomography
findings.  Australas Radiol 1999, 43:520-522.
8. Choi DS, Na DG, Byun HS, Ko YH, Kim CK, Cho JM, Lee HK: Sali-
vary gland tumors: evaluation with two-phase helical CT.
Radiology 2000, 214:231-236.
9. Okahara M, Kiyosue H, Hori Y, Matsumoto A, Mori H, Yokoyama S:
Parotid tumors: MR imaging with pathological correlation.
Eur Radiol 2003, 13(Suppl 4):L25-L33.
10. Ikeda K, Yoshida F, Suzuki H, Oshima T, Hirano K, Takasaka T: A
case report of salivary duct carcinoma.  Tohoku J Exp Med 1997,
183:233-238.
11. Donath K, Seifert G, Schmitz R: [Diagnosis and ultrastructure of
the tubular carcinoma of salivary gland ducts. Epithelial-
myoepithelial carcinoma of the intercalated ducts].  Virchows
Arch A Pathol Pathol Anat 1972, 356(1):16-31. [Article in German]
12. Witterick IJ, Noyek AM, Chapnik JS, Heathcote JG, Bedard YC:
Observation on the natural history of a parotid epithelial-
myoepithelial carcinoma of intercalated ducts.  J Otolaryngol
1993, 22:176-179.
13. Silvers AR, Som PM, Brandwein MR: Epithelial-myoepithelial car-
cinoma of the parotid gland.  Am J Neuroradiol 1996, 17:560-562.
14. Tas¸ A, Yağiz R, Altaner S, Koten M, Karasalihoglu AR: A case of epi-
thelial-myoepithelial carcinoma of the parotid gland.  Kulak
Burun Bogaz Ihtis Derg 2003, 10:171-174.Page 4 of 4
(page number not for citation purposes)


file:///data/core-remote/dit/data/Springer-OA/pdf/9a6/aHR0cDovL2xpbmsuc3ByaW5nZXIuY29tLzEwLjExODYvMTQ3Ny03ODAwLTQtMjUucGRm.pdf

Epithelial-myoepithelial carcinoma of the parotid gland, unusual malignancy radiologically simulating a benign lesion: case report

Abstract

Similar works

Full text

Available Versions

Crossref

Springer - Publisher Connector

Springer - Publisher Connector