Subcutaneous Myoepithelioma in the Extremity: A Potential Pitfall in the Differential Diagnosis of Subcutaneous Tumors

We present a rare case of myoepithelioma in the subcutaneous layer of the shoulder with ultrasonography (US) and magnetic resonance imaging (MRI). US showed a lobulated hyperechoic mass, leading to an impression of lipoma. MRI showed the mass with low signal intensity on T1-weighted images (T1WI), high signal intensity on fat-suppressed T2-weighted images (T2WI), intermediate signal intensity on T2WI, and intense enhancement with adjacent fascial thickening. Imaging findings of soft tissue myoepithelioma have not been established. We report its US and MRI features mimicking features from a lipomatous tumor to infiltrative malignancy. Although soft tissue myoepithelioma has nonspecific image findings to confirm its diagnosis, some findings may help to make the differential diagnosis. Preoperative pathologic confirmation is recommended in a soft tissue neoplasm.

Benign myoepithelioma of the soft palate: an unusual clinical entity

Myoepitheliomas are rare benign tumours that affect the exocrine glands and are sporadically located in the salivary glands. The most common location of myoepithelioma in the oral cavity is the parotid gland and it is seldom encountered in the palate. The diagnosis of this entity is challenging since its clinical presentation may resemble those of more common neoplasms, rendering a complex histopathological diagnosis. The aim of the present case report is to describe an unusual case of myoepithelioma of the soft palate in a male patient, which developed as an asymptomatic, slowly growing mass. The tumour was assessed with histopathological examination and the diagnosis was verified via immunohistochemistry. Finally, the treatment included surgical resection of the tumour and no signs of recurrence were noted 2.5 years after the surgical procedure. Early diagnosis and treatment plays an important role in the prognosis of this pathological entity.

Myoepithelial carcinoma of tibia mimic giant cell tumor: a case report with emphasis on MR features

Intraosseous myoepithelial carcinoma is an extremely rare type of bone tumor that most often presents in the long tubular bones, but also occurs in small tubular bones and the axial skeleton. We report the radiographic images and complete magnetic resonance (MR) features of a 44-year-old male with right knee pain of 7 months' duration. The radiographic findings and convention MR images indicated a giant cell tumor of the bone. The dynamic contrast-enhanced images showed a patent with the early wash-in and early wash-out usually noted in a giant cell tumor of the bone. Only water restriction on diffusion-weighted imaging (DWI) showed the malignant impression. Care should be taken when conventional images indicate giant cell tumor of the bone, as intraosseous myoepithelial carcinoma, although rare, can mimic this more common diagnosis. Further studies with DWI are warranted.

Myoepithelioma of the lateral abdominal wall: A case report

RATIONALE

Soft-tissue myoepithelioma is a rare neoplasm. It usually occurs in the distal or proximal extremities, but seldomly arises in the abdominal wall.

PRESENTING CONCERNS OF THE PATIENT

The patient is a 40-year-old woman who presented with a painless mass at the lateral abdominal wall for 6 months. Computed tomography scan revealed a lobulated and well-defined iso-density mass showing heterogeneously moderate enhancement. The mass exhibited intermediate T1 signal and obvious high T2 signal on magnetic resonance imaging.

INTERVENTIONS

The tumor was excised. Hematoxylin-eosin stain and immunohistochemical stain showed that the tumor was myoepithelioma.

OUTCOMES

The patient did not undergo chemotherapy and radiotherapy. No recurrence or metastasis was noted during the 1 year follow-up.

LESSONS

Radiologists should consider myoepithelioma in the differential diagnosis when finding a tumor in the abdominal wall.

A rare case of primary peripheral epithelial myoepithelial carcinoma of lung: Case report and literature review

BACKGROUND

Primary salivary gland-type tumors of lung are rare. Epithelial-myoepithelial carcinoma (EMC) of the lung is a minor salivary gland-type tumor subtype.

METHODS

We report a very rare case of EMC located in the peripheral left lower lobe that was diagnosed in a 58-year-old man and this is the first study in which we summarize all the patients with primary peripheral lung EMC concerned with the clinical features. Informed consent was obtained from the patient.

RESULTS

Chest computed tomography displayed an anomalous soft tissue mass with slightly lobular borders in the peripheral segment of the left lower lobe and closed to the visceral pleura. The surgery was performed by using video-assisted thoracic surgery. Grossly, the tumor was solitary, well-circumscribed, and unencapsulated endobronchial lesion. A microscopic examination revealed that it was circumscribed, although the tumor borders may show single cells or clusters of cells proliferating away from the main tumor mass. The inner tubular layer showed epithelial cell characteristics, whereas the outer layer exhibited myoepithelial cell characteristics. Immunostaining for P40, P63, and cytokeratin 5/6 was positive. However, the anaplastic lymphoma kinase-V, thyroid transcription factor-1, synaptophysin, chromogranin A and napsin A were negative.

CONCLUSIONS

Literature review showed that most of patients with peripheral EMC were asymptomatic. Computed tomography and magnetic resonance imaging scans are able to indicate the presence of peripheral EMC. Pathological analysis is an effective method to clarify the diagnosis. Surgery is a regular treatment method. To facilitate the preoperative diagnosis and avoid the misdiagnosis of such a rare disease, more cases will need to be reported.

Accessory parotid gland tumors: A series of 4 cases

Accessory parotid gland tumors are clinically rare, and their management remains unclear. In this article, we describe our experience with 4 patients-2 males and 2 females, aged 13 to 66 years-who were diagnosed with an accessory parotid gland tumor. All patients presented with an asymptomatic midcheek swelling, and all underwent fine-needle aspiration biopsy, ultrasonography, computed tomography, and magnetic resonance imaging. A standard parotidectomy was performed on all patients. Postoperatively, 2 patients were found to have a malignant tumor, while the other 2 had a pleomorphic adenoma. No patient experienced any obvious facial nerve injuries postoperatively, and no recurrences were observed. We discuss the preoperative evaluation, treatment, and prognosis of these tumors, and we briefly describe the literature. The first choice of treatment for accessory parotid gland tumors is surgical resection. In our experience, a standard parotidectomy approach is safe and cosmetically appealing.

Fine-needle aspiration of soft tissue myoepithelioma

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. We describe the cytologic features of a soft tissue myoepithelioma arising in the right lower chest wall in a 65-year-old woman. The fine-needle aspiration (FNA) smears showed round to oval, spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm, and resembled lobular carcinoma of breast. Ultrasound guided core biopsy showed the tumor cells had bland cytologic features, arranged in small cords, nests, and dissociated single cells, with no glandular differentiation or breast tissue seen. The tumor cells demonstrated immunoreactivity for cytokeratin (AE1/AE3) and glial fibrillary acidic protein, but were negative for estrogen receptor. Fluorescence in situ hybridization demonstrated the EWSR1 rearrangement, confirming the diagnosis of myoepithelioma.

Myoepithelioma of the spine: first case in the literature

Myoepithelioma is a very rare tumour. This tumor type has been reported in the soft tissue, ear, sinonasal cavity, breast and lung. Although rare, myoepithelioma can occur in bone. We present the first case of myoepithelioma in the spine, documenting the clinical, radiographic and pathological features.

Myoepithelioma of the hand and carpal tunnel: An unusual cause of median nerve compression

Myoepitheliomas are rare tumors increasingly recognized to occur in the soft tissues. Although the hand and carpal tunnel are exceptional locations, the presence of these lesions in such sites constitutes a potential cause of debilitating symptoms. We report the case of a patient with severe pain secondary to median nerve compression and displacement of flexor tendons caused by a rapidly growing myoepithelioma. This is the first sonographic description of this tumor producing carpal tunnel syndrome and disabling pain. High-resolution sonography allowed evaluation of gross tumor morphology and real-time assessment of its interactions with surrounding structures.

Epithelial-myoepithelial carcinoma in the hard palate: a case report

BACKGROUND

Epithelial-myoepithelial carcinoma (EMC) is an uncommon salivary gland tumor.

CASE

EMC arising from the minor salivary gland of the hard palate is very rare. A 70-year-old man presented with a nodular swelling in the hard palate. Fine needle aspiration cytology revealed biphasic epithelial (small cell) and myoepithelial (large/clear cell) clusters in a pseudopapillary and trabecular pattern. The cytology was reported as salivary gland neoplasm. The mass was excised and the histomorphology was suggestive of a low grade EMC. Immunohistochemistry demonstrated the biphasic nature of the tumor and confirmed the diagnosis of EMC. Follow-up for 2 years post surgery to date did not show any recurrence or metastases.

CONCLUSION

Though exact cytologic typing of EMC was not possible; this case highlights the importance of awareness of this tumor in the differential diagnosis of biphasic tumors of the salivary gland.

Case report: parachordoma of soft tissues of the arm

Parachordoma, or myoepithelioma, is a very rare tumor histologically resembling chordoma but occurring in the nonaxial soft tissues. It typically has an indolent nature, with occasional late recurrence and even rare metastases. Review of existing literature reveals a male predilection, with the tumor typically occurring in the fourth decade of life in the lower extremity. It typically is managed with wide resection. We report the case of a 60-year-old woman with a right distal upper arm parachordoma treated with wide resection of the tumor.

[Image date and clinicopathologic features of myoepithelial carcinoma in parapharyngeal space]

OBJECTIVE

To study the image data and clinicopathologic features of myoepithelial carcinoma in parapharyngeal space.

METHOD

Based on one patient with myoepithelial carcinoma of parapharyngeal space treated in our hospital, image data and clinicopathologic findings were analyzed. The clinical characteristics of myoepithelial carcinoma in head and neck region were discussed.

RESULT

CT obviously showed the mass in parapharyngeal space with destruction of temporal bone. Immunohistochemical stain showed positive staining for S-100 protein, Smooth muscle actin, Cytokeratin and Vimentin. There were otalgia, bloody pus, headache and signs of cranial nerve lesion.

CONCLUSION

Myoepithelial carcinoma was a rare malignant epithelial neoplasm and had a poor prognosis. Myoepithelial carcinoma often occurrence in salivary gland of maxillofacial region. The clinical signs were otalgia and headache in patient with myoepithelial carcinoma in parapharyngeal space. CT image showed malignant neoplasm and surrounding tissues were destroyed. Diagnosis depends on pathology and immunohistochemistry.

[Epithelial-myoepithelial carcinoma of the submandibular gland: a case report]

Epithelial-myoepithelial carcinomas are rare, low-grade, malignant salivary gland tumors. They are mostly seen in the parotid gland. The submandibular gland is a rare localization. A 54-year-old woman presented with a painless lump on the left side of the neck. Examination showed a mass with smooth surface in the left submandibular region. Fine needle aspiration cytology of the mass was reported as malignant epithelial tumor metastasis. Computed tomography of the neck showed left submandibular gland hypertrophy. Left submandibular gland excision with functional neck dissection was performed. The histopathological diagnosis was epithelial-myoepithelial carcinoma of the submandibular gland with one lymph node metastasis.

“Benign,” Metastasizing Adenomyoepithelioma of the Breast: A Report of 2 Cases

Adenomyoepitheliomas of the breast are rare tumors composed of a proliferation of 2 cell populations. For the most part, they are considered to be benign, but they locally recur. Those neoplasms that metastasize are deemed to have come from a histologically malignant primary tumor. Herein, we describe 2 cases of metastases of histologically “benign” adenomyoepitheliomas of the breast to the lung. In both cases, the primary neoplasms and the metastases did not show histologic features of malignancy. These unique cases represent another example of neoplasms that can metastasize in the absence of histologic features that would suggest malignant behavior. Establishing the diagnosis, determining optimal therapy, and predicting outcome are problematic because of the rarity of this entity. Perhaps, classification of adenomyoepitheliomas should be changed to recognize those neoplasms with malignant behavior.

Case report: myoepithelial carcinoma of the breast: a case report with imaging and pathological findings

We present a case of myoepithelial carcinoma of the breast together with illustrations of the imaging and pathological appearances as well as discussion on the management of this condition.

[Breast myoepithelioma. Report of a new case and review of literature]

Breast myoepithelioma is rare. A case is reported of a 71 year old female. The tumor was clinically, radiologically and macroscopically demarcated. Diagnosis was based on histological and immunohistochemical studies. At the time of diagnosis the tumor was composed of myoepithelial cells with few cellular atypias and a low mitotic activity. Tumor cells expressed vimentin, actin, S100 protein and cytokeratin. No local or distant metastases were found. The patient had been treated initially with a large excision of tumor. Local recurrences detected 1 year after initial surgery and showed a similar morphology and immunoreactivity with higher mitotic activity. Mastectomy with axillary dissection was performed. No recurrences and no distant metastases detected 2 years later. Myoepithelial tumors generally considered as benign or low-grade lesion can give rise to a wide range of clinical evolution.

Bronchial Epithelial-Myoepithelial Carcinoma

Epithelial-myoepithelial tumor is extremely rare as a pulmonary neoplasm. Only 20 cases have been reported to date, of which 14 were malignant. We report a case of intrabronchial epithelial-myoepithelial carcinoma in a 73-year-old man with a history of heavy smoking. The tumor was well-circumscribed and caused distal airway obstruction. Histologically, the tumor showed glandular and solid architecture. The glands were composed of an inner layer of epithelial cells and an outer layer of myoepithelial cells. The solid areas consisted of spindle-shaped myoepithelial cells. Immunohistochemical staining was positive for p53 and c-Kit (CD117). Focal atypia and increased mitotic activity were present, but no vascular invasion or nodal metastasis was identified.

Myoepithelioma of the palate: a case report

Myoepithelioma is a rare malignant neoplasm, representing about the 1% of all the salivary gland's tumors. It mainly affects women, particularly in the 7th and 8th decade of life. A case of myoepithelioma of the palate in a 70-year-old woman is described. The tumor was completely excised two years ago. Nowadays, there are no signs of local recurrence and/or distant metastasis. The discrepancy between the histological diagnosis of low-grade malignancy and the clinical aggressive behavior of the tumor is discussed.

[Salivary gland myoepithelioma]

Myoepithelioma is a rare salivary gland tumor (less than 1%) which are usually located in parotid gland and minor salivary glands. Histology and immunohistochemical features of this tumors are reviewed. We report 2 cases arising in parotid and hard palate.

Myoepithelioma of the parotid gland: a report of two cases

We describe the clinical and pathologic features of two benign myoepitheliomas of the parotid gland. Through 1985, only 42 other cases had been reported in the literature--39 benign and three malignant. Fewer than 100 cases had been reported through 1993. Since then, two other reports have been published. But are these tumors really rare, or are they simply not well recognized? It is our opinion that they are not as rare as is generally believed because the number of case reports is increasing as pathologists have become more aware of their existence.

Imaging features of myoepithelioma arising from the hard palate. A case report

A 53-year-old Japanese woman presented with a mass of the hard palate that was histologically diagnosed as myoepithelioma. By CT, the well-demarcated ovoid isodense mass showed faint contrast enhancement. By MR imaging, the mass was homogeneous and isointense on T1-weighted images with homogeneous enhancement after administration of contrast material and markedly hyperintense on T2-weighted images. Myoepithelioma should be kept in mind as differential diagnosis of hard palatine tumors.

Myoepithelioma of the lung

A 54-year-old woman with myoepithelioma, a very rare tumor of the lung, is reported. The patient presented with exertional dyspnea, cough and intermittent pleuritic chest pain. Her chest X-ray revealed a peripheral 2 cm mass in the left lower lung zone. Bronchoscopy was normal. She underwent thoracotomy in which a wedge-resection was performed. Histological examination of the specimen demonstrated myoepithelioma of the lung.

[Tumors of the parapharyngeal space: case report of clear cell myoepithelioma of the parotid gland and review of literature]

The parapharyngeal space is a deep neck region and can be the site of a wide range of neoplasms, including primary benign or malignant tumors, metastatic tumors, neoplasms invading the parapharyngeal space from the adjacent regions and neoformations stemming from systemic processes. Tumors of the parapharyngeal space are, nevertheless, relatively rare and account for 0.5-0.8% of all head and neck tumors. Most are benign tumors originating in the deep lobe of the parotid gland and the minor salivary glands. The most frequent tumor is pleomorphic adenoma while myoepithelioma accounts for just 1% of all salivary gland tumors. The present case report involves a case of myoepithelioma of the deep parotid gland lobe, arising in the parapharyngeal space. Together with a review of the literature, considerations are presented on the clinical and radiological evaluation, differential diagnosis and treatment of these lesions.

Imaging tumors of the minor salivary glands

Magnetic resonance imaging evaluations of nine histopathologically confirmed minor salivary gland tumors were made retrospectively and compared with evaluations of images obtained by computed tomography. All tumors had low-to-intermediate T1 signal intensities and intermediate-to-high T2 signal intensities. Malignant tumors had an irregular margin in all but one case. Benign tumors invariably had well-defined margins. In terms of tumor margination, the magnetic resonance imaging findings correlated well with the histopathologic findings. Magnetic resonance imaging demonstrated the internal architecture of the minor salivary gland tumors multidirectionally and was superior to computed tomography in this respect and in the ability to locate the tumors.

Observations on the natural history of a parotid epithelial-myoepithelial carcinoma of intercalated ducts

A case report of a parotid epithelial-myoepithelial carcinoma (EMC) of intercalated ducts is presented. There were no changes in clinical characteristics or growth over a four-year period as documented by repeated clinical examination and serial ultrasounds. This neoplasm may be mistaken for an adenoid cystic carcinoma on fine needle aspiration and is believed to represent an adenocarcinoma of low malignant potential. The imperceptible growth of this epithelial-myoepithelial carcinoma is in accord with a low malignant potential.

Malignant myoepithelioma of the breast: a case report

Myoepithelioma of the breast is rare. It is usually benign but may be locally aggressive. Its clinical behavior is unknown, but if it follows the course of similar tumors of the salivary glands, the likelihood of systemic spread is very low. Mammographic findings are nonspecific, and ultimate identification is based on ultrastructural criteria.

Adult renal myoepithelial hamartoma

A renal myoepithelial hamartoma presented as a lucent filling defect with gross hematuria in an adult female. Preoperative studies caused conflicting impressions. The predominance of smooth muscle and incorporated tubuloepithelial elements characterize the tumor as a hamartoma of myoepithelial type. Pertinent review of the literature confirms the rarity of this lesion in adults.