1/15. Epithelial-myoepithelial carcinoma arising in pleomorphic adenoma of the palate.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.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/15. Adenomatoid hyperplasia of the palate mimicking clinically as a salivary gland tumor.This report describes an illustrative case of adenomatoid hyperplasia (AH) of the minor salivary glands on the palate of a 31-year-old man. The clinical features of the present lesion corresponded with those of pleomorphic adenoma, but histologically large lobules of normal-appearing mucous acini were found. The cell proliferative activity demonstrated in histological sections, by an immunohistochemical staining of proliferating cell nuclear antigen and Ki-67, showed no statistically significant differences among AH and a matched control group of normal palatal salivary glands. This case suggests that AH apparently exhibits an idiopathic, focal hypertrophic lesion of intraoral mucous glands with limited growth potential.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/15. Hyaline cell-rich chondroid syringoma: case report and review of the literature.Hyaline cell-rich chondroid syringoma (HCRCS) is a rare benign cutaneous neoplasm composed of cells with eosinophilic hyaline cytoplasm and plasmacytoid features, the origin of which remains elusive. To the best of our knowledge, only eight cases of this entity have been reported so far, and none of them was submitted to a large panel of myoepithelial markers. We report on a case of a previously healthy 29-year-old male patient who presented with a slowly enlarging flesh-colored nodule on the palmar aspect of the tenar region of his left hand, measuring 2 cm in maximum diameter. The nodule was "shelled-out" and submitted to light microscopy, immunohistochemistry, and ultrastructural examination. Histopathologic analysis disclosed a lobulated neoplasm composed of hyaline cells with plasmacytoid features showing ovoid nuclei, with occasional invaginations, finely granular chromatin, and discrete nucleoli; the cytoplasm was deeply eosinophilic with occasional dot-shaped paranuclear hyaline inclusions. On immunohistochemical evaluation, hyaline cells were strongly and diffusely positive for S-100 protein, vimentin, pan (CAM 5.2) and high molecular weight (34betaE12) cytokeratins; these cells were focally positive for GFAP, maspin, neuron-specific enolase, and cytokeratin 14. Alpha-smooth muscle actin, epithelial membrane antigen, carcinoembryonic antigen, collagen IV, Gp100 (HMB-45), and p63 were negative in neoplastic hyaline cells. Ultrastructural analysis disclosed cells with ovoid nuclei showing occasional invaginations and nuclear pockets; the cytoplasm was rich in meshworks of non-bundling intermediate filaments and a variable amount of rough endoplasmic reticulum cisternae. Based on our findings and those previously reported, hyaline cells of HCRCS might posses an aberrant myoepithelial differentiation. Most importantly, pathologists need to be aware of the histologic and immunohistochemical features of HCRCS to avoid a misdiagnosis of highly malignant neoplams, such as malignant melanoma and extra-skeletal myxoid chondrosarcoma.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
4/15. Chondroid syringoma with small tubular lumina.BACKGROUND: Chondroid syringoma or mixed tumor of the skin is a rare epithelial tumor with eccrine differentiation. The variant with small tubular lumina is extremely uncommon. OBJECTIVE: Chondroid syringoma is usually present as a single subcutaneous nodule. This report describes a man with multiple scalp lesions exhibiting features of chondroid syringoma with small tubular lumina. methods: A Pathological examination of surgically resected multiple scalp nodules was carried out by routine histology and immunohistochemistry. The following antibodies were found: cytokeratin, epithelial membrane antigen, and vimentin. RESULTS: Microscopic findings revealed multiple chondroid syringoma with small tubular lumina. The tumor cells were positive for high- and low-molecular-weight keratin, epithelial membrane antigen, and vimentin. CONCLUSION: This is the first report of multiple chondroid syringoma with small tubular lumina.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
5/15. Pleomorphic adenoma arising in an accessory lacrimal gland of Wolfring.PURPOSE: To describe a patient with pleomorphic adenoma arising in an accessory lacrimal gland of Wolfring in the lower lid and to illustrate the immunohistochemical and molecular cytogenetics. DESIGN: Single interventional case report. methods: A 62-year-old man presented with a 20-year history of a painless slowly growing mass at the temporal part of the right lower eyelid. Histological, immunohistochemical, and fluorescence in situ hybridization studies of the excised tumor were performed. RESULTS: Histological evaluation showed many glandular elements embedded in a myxoid stroma. The tumor was situated beneath an area of a normal accessory lacrimal gland of Wolfring and in close association with normal meibomian glands. Myoepithelial tumor cells in the myxoid stroma reacted strongly with an antibody against glial fibrillary acidic protein, which did not bind to normal lacrimal gland tissue. Tumor cells with both epithelial and myoepithelial morphologies reacted positively for both pleomorphic adenoma gene-1 and high-mobility group A2 proteins. fluorescence in situ hybridization analysis showed no evidence of clonal translocations or numerical abnormalities involving chromosome 8 or 12. CONCLUSIONS: Pleomorphic adenoma of the accessory lacrimal gland is an exceedingly rare tumor of the ocular adnexa. glial fibrillary acidic protein seems to be a tumor-associated antigen. Genetically, this case of pleomorphic adenoma arising from an accessory lacrimal gland of Wolfring is identical with those originating from salivary glands.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/15. True malignant mixed tumor of the submandibular gland.A case of true malignant mixed tumor of the submandibular gland is reported. The submandibular tumor, occurring in a 52-year-old man, started to grow rapidly after a long history without any change in size. Surgical resection was carried out and the resected tumor measured 5.5 cm with a cut surface showing mixed solid structures. Microscopically, the tumor had both carcinomatous and sarcomatous elements, the former consisting of poorly differentiated adenocarcinoma with squamous cell differentiation and the latter consisting of osteosarcoma with chondrosarcomatous and fibrosarcomatous elements. A remnant of benign pleomorphic adenoma could also be identified. Immunohistochemical study demonstrated keratin and epithelial membrane antigen in the carcinoma cells and vimentin in all elements of the osteosarcoma. It is assumed from these clinical and histological findings that the tumor had transformed from a pre-existing benign pleomorphic adenoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/15. So-called mixed tumor of the skin on the wrist: an immunohistochemical study.A case of so-called mixed tumor of the skin arising on the wrist was reported. Immunohistochemical staining of keratins of several molecular weights (AE1/AE3, RCK102, NCL-5D3 and 35 beta H11), carcinoembryonic antigen (CEA), S-100 protein, and desmin was performed. AE1/AE3 and RCK102 were positive in all the tumor cells; CEA, NCL-5D3 and 35 beta H11 were positive mainly in luminal cells of the tubuloalveolar structures. S-100 protein was positive in peripheral cells of the tubular lumina and in scattered cells in the mucous stroma. desmin was negative in all the tumor cells. Immunohistochemical findings lent further support to the hypothesis that so-called mixed tumor of the skin differentiates into the secretory and ductal portions of the sweat gland.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/15. Unusual mesenchymal and mixed tumors of the salivary gland. An immunohistochemical and flow cytometric analysis of three cases.Histological, immunohistochemical, and flow cytometric characteristics of three unusual parotid gland tumors are described. The patients were adult white men with carcinoma ex pleomorphic adenoma, true malignant mixed tumor, and primary parotid gland chondrosarcoma. The carcinoma ex pleomorphic adenoma showed evidence of simultaneous epithelial, myoepithelial, and mesenchymal differentiation by immunohistochemistry. The true malignant mixed tumor exhibited variable positivity for two keratins, vimentin, proliferating cell nuclear antigen, Ki67, and p53. The chondrosarcoma initially stained for vimentin, S100, muscle-specific actin, proliferating cell nuclear antigen, and Ki67, but it lost actin expression in its first recurrence, accompanied by more extensive Ki67 staining. dna ploidy varied from diploid to aneuploid with intratumoral variation in the carcinosarcoma. S-phase fractions ranged from 2.43% to 13.9%. The findings underscore the diversity of tumors that may be pathogenetically related to, and at times derived from, pleomorphic adenoma.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
9/15. Clear cell epithelial-myoepithelial carcinoma arising in pleomorphic adenoma of the lacrimal gland.BACKGROUND: A 63-year-old man had an 8-year history of painless proptosis, which had noticeably increased over the last 2 months. A mass was palpable in the left lateral canthus. Computed tomographic studies showed a globular mass with small foci of calcification involving the lacrimal gland. After an incisional biopsy, a histologic diagnosis of clear cell epithelial-myoepithelial carcinoma was made and an orbital exenteration was performed. FINDINGS: Results of histologic examination of the mass showed a partially encapsulated, clear cell epithelial-myoepithelial carcinoma with an associated pleomorphic adenoma (benign mixed tumor). Immunohistochemical studies disclosed strong immunoreactivity to cytokeratin (AE1/AE3), epithelial membrane antigen, S-100 protein, and alpha-actin. CONCLUSION: Although a clear cell myoepithelial carcinoma rarely has been reported in association with a pleomorphic adenoma of the submandibular gland, to the authors' knowledge, this combination has never been reported in the lacrimal gland, nor has a clear cell epithelial-myoepithelial carcinoma ever been reported in this anatomic location. The differential diagnosis of lesions with prominent clear cells involving the lacrimal gland is extensive and includes clear cell variants of acinic cell carcinoma and oncocytoma, mucoepidermoid carcinoma, and others.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/15. Unique chromosomal rearrangement and mucin production in a novel salivary myoepithelial cell strain.Pleomorphic adenoma is the most frequently occurring benign neoplasm of the salivary glands. We describe the culture characteristics, biochemical properties, immunohistochemical staining, and genetic rearrangements found in a novel cell strain (UNC4) established from a human benign pleomorphic adenoma. serum and/or butyrate stimulation of UNC4 cultures results in upregulation of mucin production. This is confirmed by periodic acid-Schiff, periodic acid-Schiff digest, alcian blue, and mucicarmine staining as well as by gel electrophoresis. Fluorescent immunohistochemical studies detect cellular cytokeratin, desmin, and epithelial membrane antigen. Immunofluorescent staining for S100 protein is negative. Examination of the karyotype of UNC4 reveals a unique rearrangement between one chromosome 8 and the two chromosome 9s involving the 8q12 locus. UNC4 represents an in vitro model of a benign salivary gland neoplasm that can provide the basis for further molecular and biochemical studies on genetic rearrangement and salivary mucin production.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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