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A retrospective study of salivary gland tumors. 143 cases treated during a 27-year period
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P23-6Diagnosis of neoplasm
P23-6 Diagnosis of neoplasm 3. Malignant Myoepithelioma of the Mouth Floor 1. A Case of Myoepithelioma of the Palate
Mori, M. 1, Morikawa, M. 1, Kuroda, T.1, Sakou, j.l, Kakudo, K. 1, Shirasu, R. 1, Tanaka, A. 2
Ohtake, If., Mogi, K., lizuka, M., Tuchiya, M., Sasaoka, K. Department of OS, Gunma Univ., Maebashi, Japan Myoepithelioma is a rare salivary gland neoplasm. A case of myoepithelioma of the palate is presented. A 26-year-old woman complaining chiefly of swelling in the palate was referred to us by her dentist for diagnosis and treatment on April 15, 1996, Clinical examination disclosed a swelling, approximately 30-20 ram, in the right side of the palate. A clinical diagnosis of adenoma was made and the tumor was excised under general anesthesia. The palatal bone was intact. There have been no signs of recurrence in the operated region for a period of approximately one year. A microscopic view of the lesion, stained with hematoxylin and eosin, revealed a solid growth pattern of plasmacytoid cells with eccentric nuclei, discrete nucleoli, and hyalinecytoplasm. Only a few cellular atypisms were found. A histopathological d~agnosis of myoepithelioma was made.
2. Plasmacytoid Myoepithelioma of the Palate
Kanazawa, H., Furuya, T. Div. Oral Surgery, Kimitsu Chu-o Hospital, Kisaradu, Japan Myoepitheliomas are quite rare, generally benign neoplasms that account for less than 1% of all salivary gland tumors. A case report of a plasmacytoid myoepithelioma of minor salivary gland origin is presented, and a comprehensive review of the English literature with regard to immunohistochemical features will also be provided.
Case Report A 42-year-old Japanese woman presented with a chief complaint of an asymptomatic palatal mass that had slowly enlarged over one year. Upon oral examination, a nodule measuring 8 mm in diameter was found in the left posterior part of the hard palate. It was firm and rubbery in consistency and covered with normal mucosa. Radiological examination revealed nothing. A clinical diagnosis of minor salivary gland tumor was made, and the tumor was excised with wide soft tissue margins. The specimen was solid and wellencapsulated. The tumor lobes showed a homogenous population of ovoid cells with eccentric nuclei and abundant eosinophilic cytoplasm. Neither ductal differentiation nor chondroid area was identified in the neoplasm, but myxomatous stroma was observed. Immunohistochemical study revealed that the cells were immunoreactive for vimentin and S-100 protein and they did not react with antibodies to epithelial membrane antigen or smooth-muscle actin.
~First Department of OMS, and 2Department of Oral Pathology, Osaka Dental Univ., Osaka, Japan Malignant myoepithelioma is a rare malignant epithelial tumor composed of atypical myoepithelial cells with increased mitotic activity and aggressive growth, The cytological features of individual cells and general morphological features are very similar to benign myoepithelial cells of pleomorphic adenoma. The differential diagnosis of various salivary gland tumors is important. Malignant myoepitheliomas are very uncommon neoplasms that have only rarely been reported in the literature. Most tumors occur in the parotid gland. We report the clinical and histological findings of a case of malignant myoepithelioma of the mouth floor. A 67-year-old woman was referred to our hospital complaining of a mass in the mouth floor on the left side. The mass was elastic hard, tender, mobile, and approximately 15 mm in diameter with sharp margins. The left submandibular lymph nodes were enlarged and tender. M R I revealed a mass with sharp margins in the left mouth floor. The mass was excised under local anesthesia for biopsy. Histopathologic examination of the excised specimen revealed that the clear cells had increased in number and formed a nest. In the nest, keratinization and hyalinization were observable. Tumor cells were spindle-shaped or round in morophology with pleomorphism, in some places, with mitosis or necrosis. The stroma in some areas of the tumors was myxoid. F r o m these findings, a diagnosis of malignant myoepithelioma was made, and the tumor and surrounding tissues were resected under general anesthesia. The patient has not shown recurrence or metastasis as of six months after her surgery.
4. A Retrospective Study of Salivary Gland Tumors. 143 cases treated during a 27-year period
lwanari, S., Aisaki, K., Sato, J., Takeda, A., lshii, T., Oda, Y., Takayama, Y, Kudo, L Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry, Japan From 1970 to 1996, 143 cases of salivary gland tumors were treated at the Department of Oral and Maxillofacial Surgery of the Nihon University School of Dentistry. The 143 cases were retrieved from a pool of 9,300 oral biopsy specimens submitted during this 27-year period. The diagnoses of individual tumors were based on the 1991 W H O classification. Tumors were analyzed according to histological type, location, and the age and sex of the patient, and a provisional clinical diagnosis was obtained from the clinical record of each case. The 143 cases included 88 benign tumors, 54 malignant tumors, and 1 unclassified tumor of the salivary glands. Pleomorphic adenomas were the most frequent his-
P23-6Diagnosis of neoplasm
P23-6 Diagnosis of neoplasm 3. Malignant Myoepithelioma of the Mouth Floor 1. A Case of Myoepithelioma of the Palate
Mori, M. 1, Morikawa, M. 1, Kuroda, T.1, Sakou, j.l, Kakudo, K. 1, Shirasu, R. 1, Tanaka, A. 2
Ohtake, If., Mogi, K., lizuka, M., Tuchiya, M., Sasaoka, K. Department of OS, Gunma Univ., Maebashi, Japan Myoepithelioma is a rare salivary gland neoplasm. A case of myoepithelioma of the palate is presented. A 26-year-old woman complaining chiefly of swelling in the palate was referred to us by her dentist for diagnosis and treatment on April 15, 1996, Clinical examination disclosed a swelling, approximately 30-20 ram, in the right side of the palate. A clinical diagnosis of adenoma was made and the tumor was excised under general anesthesia. The palatal bone was intact. There have been no signs of recurrence in the operated region for a period of approximately one year. A microscopic view of the lesion, stained with hematoxylin and eosin, revealed a solid growth pattern of plasmacytoid cells with eccentric nuclei, discrete nucleoli, and hyalinecytoplasm. Only a few cellular atypisms were found. A histopathological d~agnosis of myoepithelioma was made.
2. Plasmacytoid Myoepithelioma of the Palate
Kanazawa, H., Furuya, T. Div. Oral Surgery, Kimitsu Chu-o Hospital, Kisaradu, Japan Myoepitheliomas are quite rare, generally benign neoplasms that account for less than 1% of all salivary gland tumors. A case report of a plasmacytoid myoepithelioma of minor salivary gland origin is presented, and a comprehensive review of the English literature with regard to immunohistochemical features will also be provided.
Case Report A 42-year-old Japanese woman presented with a chief complaint of an asymptomatic palatal mass that had slowly enlarged over one year. Upon oral examination, a nodule measuring 8 mm in diameter was found in the left posterior part of the hard palate. It was firm and rubbery in consistency and covered with normal mucosa. Radiological examination revealed nothing. A clinical diagnosis of minor salivary gland tumor was made, and the tumor was excised with wide soft tissue margins. The specimen was solid and wellencapsulated. The tumor lobes showed a homogenous population of ovoid cells with eccentric nuclei and abundant eosinophilic cytoplasm. Neither ductal differentiation nor chondroid area was identified in the neoplasm, but myxomatous stroma was observed. Immunohistochemical study revealed that the cells were immunoreactive for vimentin and S-100 protein and they did not react with antibodies to epithelial membrane antigen or smooth-muscle actin.
~First Department of OMS, and 2Department of Oral Pathology, Osaka Dental Univ., Osaka, Japan Malignant myoepithelioma is a rare malignant epithelial tumor composed of atypical myoepithelial cells with increased mitotic activity and aggressive growth, The cytological features of individual cells and general morphological features are very similar to benign myoepithelial cells of pleomorphic adenoma. The differential diagnosis of various salivary gland tumors is important. Malignant myoepitheliomas are very uncommon neoplasms that have only rarely been reported in the literature. Most tumors occur in the parotid gland. We report the clinical and histological findings of a case of malignant myoepithelioma of the mouth floor. A 67-year-old woman was referred to our hospital complaining of a mass in the mouth floor on the left side. The mass was elastic hard, tender, mobile, and approximately 15 mm in diameter with sharp margins. The left submandibular lymph nodes were enlarged and tender. M R I revealed a mass with sharp margins in the left mouth floor. The mass was excised under local anesthesia for biopsy. Histopathologic examination of the excised specimen revealed that the clear cells had increased in number and formed a nest. In the nest, keratinization and hyalinization were observable. Tumor cells were spindle-shaped or round in morophology with pleomorphism, in some places, with mitosis or necrosis. The stroma in some areas of the tumors was myxoid. F r o m these findings, a diagnosis of malignant myoepithelioma was made, and the tumor and surrounding tissues were resected under general anesthesia. The patient has not shown recurrence or metastasis as of six months after her surgery.
4. A Retrospective Study of Salivary Gland Tumors. 143 cases treated during a 27-year period
lwanari, S., Aisaki, K., Sato, J., Takeda, A., lshii, T., Oda, Y., Takayama, Y, Kudo, L Department of Oral and Maxillofacial Surgery, Nihon University School of Dentistry, Japan From 1970 to 1996, 143 cases of salivary gland tumors were treated at the Department of Oral and Maxillofacial Surgery of the Nihon University School of Dentistry. The 143 cases were retrieved from a pool of 9,300 oral biopsy specimens submitted during this 27-year period. The diagnoses of individual tumors were based on the 1991 W H O classification. Tumors were analyzed according to histological type, location, and the age and sex of the patient, and a provisional clinical diagnosis was obtained from the clinical record of each case. The 143 cases included 88 benign tumors, 54 malignant tumors, and 1 unclassified tumor of the salivary glands. Pleomorphic adenomas were the most frequent his-