Malignant myoepithelioma. Clinicopathological and immunohistochemical characteristics

Myoepithelioma- An Uncommon Parotid Tumour in An Adolescent

Myoepitheliomas are uncommon neoplasms of major and minor salivary glands. These tumours are encapsulated and slow growing in nature and are benign in majority of the cases. The mean age of presentation is 40 years and this entity is rarely reported in younger age groups. Here, we seek to report a rare case of a 10-year-old patient who presented with a swelling below the right ear. Clinical and radiological evaluation revealed a mass in the parotid gland. This patient was treated with a superficial parotidectomy and subsequent histopathological examination revealed it to be a myoepithelioma.

Cytopathology of salivary gland myoepithelial carcinoma: A study of 13 cases and review of the literature

INTRODUCTION

Myoepithelial carcinoma (MECA) is an infrequently recognized salivary gland (SG) neoplasm that commonly develops within a preexisting pleomorphic adenoma (MECA ex PA). Fine-needle aspiration (FNA) biopsy reports of this neoplasm are largely restricted to small series and single case reports.

METHODS

Our cytopathology files were searched for examples of SG MECA/MECA ex PA having confirmatory histopathologic verification. Conventional FNA biopsy smears were performed, and exfoliative specimens processed using standard techniques.

RESULTS

Thirteen cases from 9 patients (M:F = 3.5:1; age range: 36 to 95 years, mean age = 60 years) met inclusion criteria. FNA biopsy sites included parotid gland (4), trunk (2), scalp (2), and neck (2). Exfoliative specimens included pleural fluid (1), bronchial brushing (1), and bronchoalveolar lavage (1). Most cases were metastatic deposits (8; 62%), 4 were primary neoplasms, and 1 a local recurrence. FNA diagnoses were MECA ex PA (6; 46%), myoepithelial neoplasm (2), PA (2), basaloid neoplasm (1), atypical myoepithelial cells (1), and myxoma (1). Ancillary testing in 2 cases showed positive staining for myoepithelial markers. Cytologic features were that of a low-grade neoplasm composed principally of epithelioid/polygonal cells exhibiting minimal if any cytologic atypia. Myxoid and chondromyxoid stroma was often the dominant feature in MECA ex PA aspirates.

CONCLUSION

In the primary setting, a cytologic diagnosis of MECA/MECA ex PA is extremely challenging if at all possible. Due to overwhelming amounts of stroma, the diagnosis may be challenging in some cases of metastatic MECA ex PA.

Myoepithelial Carcinoma Arising in a Plasmacytoid Myoepithelioma of the Parotid Gland Synchronized with Melanoma: A Case Report and Review of the Literature

Myoepithelial carcinoma, also known as malignant myoepithelioma, is considered an extremely rare (0.45-1%) malignant salivary gland neoplasm. Approximately 100 cases have been reported in the English-language literature on myoepithelial carcinoma. The majority of the myoepitheliomas described in the literature have been benign, and the malignant counterpart is considered rare (<1%). Such a tumor may appear de novo or rarely develop from a preexisting pleomorphic adenoma (<20%), and in exceedingly rare cases (<0.5%), it has arisen from a benign myoepithelioma (i.e., plasmacytoid myoepithelioma). To our knowledge, no case of myoepithelial carcinoma of the parotid gland arising in a plasmacytoid myoepithelioma synchronized with melanoma has been reported to date. The treatment of myoepithelial carcinoma has been mainly surgical, including wide excision with free margins, with or without nodal dissection. The roles of chemotherapy and radiotherapy have not yet been established. We report a case of myoepithelial carcinoma of the parotid gland arising in a plasmacytoid myoepithelioma synchronized with melanoma in a 40-year-old woman. In our case, a complete response was achieved with surgery followed by adjuvant chemotherapy based on carboplatin and paclitaxel concurrent with radiotherapy.

Benign myoepithelioma of the hard palate: a clinical and histological diagnostic challenge. Case report and literature review

Introduction: Myoepithelioma (ME) is a rare salivary gland tumor. Constructed aroung a clinical case, this article aims to gather up up-to-date epidemiological, clinical and histological data about myoeptihelioma with emphasis on the diagnostic approach and differential diagnoses, paraclinical exams and the main histological features reported for its characterization. Observation: A 41-year-old female, presenting a 1-year slowly enlarging palatine nodule was referred to the Oral Pathology Consultation. Clinical data and paraclinic examination were non-specific. A thorough histological examination, comparing clinical data with cyto-architectural and immunostaining profile of the tumor allowed a positive diagnosis of ME. Discussion: The clinical aspect of ME is close from other more frequent tumors within the same areas. Accordingly, its discovery is often incidental and its diagnosis histological. ME display variable architecture and composition, requiring full tumor examination for proper diagnosis. When benign, ME act as mixed tumor regarding local extension, prognosis and recurrence. Malignant ME behaves as a low-grade malignant tumor with metastatic potential. Conclusion: Despite its rarity, ME should be hypothesized in front of a palatine nodule. Clinician and pathologist should be particularly cautious regarding nature, malignancy and follow-up of this tumor, since few data are up-to-now available.

(125)I interstitial brachytherapy for the treatment of myoepithelial carcinoma of the oral and maxillofacial region

PURPOSE

This study evaluated the treatment of myoepithelial carcinoma (MC) of the oral and maxillofacial region with radioactive iodine ((125)I) seed implantation.

METHODS AND MATERIALS

Twenty-seven patients with MC in the oral and maxillofacial region were treated with (125)I seed implantation between March 2006 and October 2012. Thirteen of the 27 patients (8/8 patients with primary disease and 5/19 patients with recurrent disease) were treated on an adjuvant setting after resections, and the other 14 patients were treated by brachytherapy after a recurrence precluding a surgical resection for salvage. The sites of the MC were the parotid for 18 patients, oral cavity for 2 patients, and base of skull for 7 patients. Recurrence-free survival (RFS), overall survival (OS) rates, and side effects were retrospectively reviewed.

RESULTS

Patients were followed for 6-105 months (median 37 months). The 3- and 5-year RFS rates were 51.9% and 46.1%, respectively. The 3- and 5-year OS rates were 68.6% and 51.5%, respectively. The OS and RFS were significantly better among the 8 patients treated upfront in comparison with the 19 patients treated for salvage at relapse. The OS was worst for the 7 patients with base of skull region disease. No severe complications were observed during followup.

CONCLUSIONS

This study showed (125)I brachytherapy is a feasible and effective modality for the treatment of MC. These findings should be interpreted cautiously due to the small number of patients and the relatively short followup.

Malignant myoepithelioma of the maxilla posing a diagnostic dilemma

Malignant myoepithelioma is an extremely rare tumor of the salivary glands. Myoepitheliomas make up less than 1% of all salivary gland tumors. We report of a case of malignant myoepithelioma of the upper jaw in a 55-year old man. The tumor primarily arose from the maxillary sinus and secondarily involved the palate. A diagnosis of pleomorphic adenoma was interpreted, following fine needle aspiration cytology and spindle cell tumor, following incision biopsy with a dilemma. The surgery consisted of subtotal maxillectomy preserving the infra orbital rim and posterior wall of the maxillary sinus, with wide local resection. Neck dissection was not carried out. The final histologic diagnosis of the tumor proper was made out to be malignant myoepithelioma. Three different diagnoses were made in dilemma to reach out the final diagnosis, which was confirmed by immunohistochemistry. The case presented and discussed, underscores the importance of diagnosis and treatment of this rare clinicopathologic entity.

Myoepithelial carcinoma inside of maxilla bone: A case report

Myoepithelial carcinoma (MC) is a rare type of carcinoma occurring mainly in the parotid gland, while other carcinomas occur in submandibular or the accessory glands of the oral cavity. They may arise from the glands of the respiratory tract. However, primary MC of the bone is extremely rare. In the present study, a rare case of a 41-year-old woman with MC in the maxilla bone was reported. Following misdiagnosis as a bone cyst, a local excision was performed. The patient then presented with an extremely high malignancy and showed no response to chemoradiation treatment. The bone cyst was thought to be MC, thus early diagnosis with complete surgical excision was highly important. After confirmation of MC, a secondary extensive surgery may be crucial, following the primary local surgical resection.

Malignant myoepithelioma of the soft palate

Malignant myoepitheliomas (MM) (myoepithelial carcinomas) are rare tumors representing <1% of salivary gland tumors. They are characterized as being locally aggressive. Rarely do they present distant metastases; however, when they do metastasize the sites most affected are the lungs, liver, pleura, peritoneum and skin. They may originate de novo in a pleomorphic adenoma or a benign myoepithelioma. We report the case of a patient with a submucosal lesion of the soft palate measuring ∼4cm×3cm. The patient underwent transoral resection with a microscope and CO2 laser. Histopathological report was MM originating in a pleomorphic adenoma. Management of this neoplasm is controversial. Myoepithelial carcinoma is a rare neoplasm whose diagnosis includes immunohistochemical (IHC) studies. Surgery is the cornerstone of treatment. Management with laser surgery may preserve the function of the soft palate without deterioration of the quality of life in these patients.

Malignant myoepithelioma of the palate: a case report with review of the clinicopathological characteristics

A malignant myoepithelioma is one of the rarest salivary gland neoplasms which may either arise de novo or develop within a preexisting pleomorphic adenoma or benign myoepithelioma. The parotid gland is the most common primary site and the palate the most common intra-oral site of occurrence. Herein is present a case of a malignant myoepithelioma arising in the hard palate of a 79-year-old woman. The lesion had been examined by biopsy at another hospital, and diagnosed as a poorly differentiated squamous cell carcinoma. The patient underwent a wide local tumor resection. Examination of the resection specimen showed the characteristic histopathological and immunohistochemical features of a malignant myoepithelioma. Five months after the operation, the patient was well without evidence of recurrence or metastasis.

Myoepithelial carcinoma of the retromolar area in a young female. A rare case report

We present a case of a 34-year-old woman with myoepithelial carcinoma of the retromolar area. Myoepithilial carcinoma is a rare tumor of small salivary glands most usually located in the parotid gland. The major differential diagnosis of myoepithelioma is from pleomorphic adenoma. Little is known about the clinical and biological behavior and the prognosis of myoepithelial carcinoma and there is no consensus for its treatment. It is considered a low-grade malignancy; it sometimes shows aggressive behavior and may locally recur. Our patient was treated successfully with wide-local resection and remained free of disease for 6 months.

Myoepithelial carcinoma of the submandibular gland: report of a case with multiple cutaneous metastases

Myoepithelial carcinoma is a rare and aggressive neoplasm of the salivary glands. One-third of the patients may develop regional distant metastases, and lungs and kidneys have been regarded as the most usual sites for implantation. There is, however, little information on the metastatic behavior of this malignancy. We report the first case of patient with multiple cutaneous metastases from a myoepithelial carcinoma of the submandibular gland, which depicted a very aggressive clinical course.

[Myoepithelial carcinoma ex-pleomorphic adenoma of the parotid gland]

INTRODUCTION

Myoepithelial carcinoma accounts for less than 1% of salivary gland malignant tumors. It may develop de novo or, in approximately 50% of the cases, from a pleomorphic adenoma.

OBSERVATION

A 57-year-old man with a history of a pleomorphic adenoma of the parotid treated surgically 6 years earlier, presented with a 2 cm tumor mass, palpable in the scar region. The histological examination and immunohistochemical study revealed a low-grade myoepithelial carcinoma. The patient had no complementary treatment. He presented 5 years later with a 2 cm parapharyngeal recurrence which was resected. There was no evidence of recurrent tumor or of distant metastasis at 4 year follow-up.

DISCUSSION

Although myoepithelial cells are often predominant in pleomorphic adenomas, carcinomas developing in pleomorphic adenomas show in most cases a glandular differentiation and myoepithelial carcinomas are rare. Currently the diagnostic criteria, the prognosis, and the management of myoepithelial carcinomas are not well documented. Invasive carcinomas developing in pleomorphic adenoma are known to be highly aggressive neoplasms and myoepithelial carcinomas ex-pleomorphic adenoma seem to have a better prognosis. Our reported case was characterized by the weak aggressiveness of the lesion.