1/113. Melanin pigmented oncocytic metaplasia of the nasopharynx.A 64-year-old man presented with a history of discomfort of the throat of a few weeks' duration. Nasoscopic examination revealed multiple small, brown pigmentations at the left suprapharynx, the base of the left nasal cavity and the pharyngeal openings of the auditory tube on both sides. Microscopically, the lesion showed a glandular pattern of oncocytic epithelium with abundant pigmented granules and melanophages in the surrounding stroma. Immunohistochemically, the dendritic cells in the basal layer were positive for S-100 protein. Electron microscopic study revealed numerous fully melanized melanosomes and hypertrophied mitochondria in the oncocytic cells. Oncocytic cells do not produce melanin for themselves, melanin granules apparently being transferred from the adjacent dendritic cells to the oncocytic cells.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
2/113. Squamous cell carcinoma arising in a Warthin's tumor.Warthin's tumor is a well-defined salivary gland neoplasm consisting of epithelial and lymphoid components. However, malignant transformation is extremely rare. Such a patient who developed squamous cell carcinoma within a Warthin's tumor of the parotid gland is described and possible pathogenesis is discussed.- - - - - - - - - - ranking = 2keywords = gland (Clic here for more details about this article) |
3/113. Gastric adenocarcinoma associated with fundic gland polyps in a patient with attenuated familial adenomatous polyposis.Familial adenomatous polyposis (FAP) is a rare autosomal dominant precancerous condition of the colon caused by mutations in the adenomatous polyposis coli (APC) tumor suppressor gene. FAP is characterized by the appearance of innumerable adenomatous polyps throughout the large bowel. Fundic gland polyps are the most common gastric lesion in FAP. It is generally believed that fundic gland polyps have little or no potential for malignant transformation in the population at large, and only a few case reports describe the development of high grade dysplasia or gastric adenocarcinoma associated with diffuse fundic gland polyposis in patients with FAP. We report the second case of gastric adenocarcinoma intimately associated with fundic gland polyposis in a family with an attenuated form of FAP. The patient had undergone routine screening per current guidelines because of his known mutation in the APC gene. This suggests that malignant transformation of fundic gland polyps in patients with FAP occur more frequently than previously believed. Current screening recommendations may not be sufficient for patients with FAP or its attenuated forms.- - - - - - - - - - ranking = 9keywords = gland (Clic here for more details about this article) |
4/113. Middle ear adenoma with neuroendocrine differentiation.The lining of the middle ear cleft is normally a thin modified respiratory type mucosa. Normal mucosa of the middle ear is devoid of salivary type seromucous glands. Middle ear adenoma is a rare tumor that seems to be derived from the middle ear mucosa. This tumor has been previously described under a variety of names because of its different nature and biological behavior. We herein report a case of middle ear tumor that shows adenomatous and neuroendocrine features. A 64-year-old woman presented with a history of hearing loss, tinnitus and stuffy feeling of the right ear. The patient was treated two times for ear polyp. She finally underwent a tympanomastoidectomy and there was no evidence of recurrence 18 months after the procedure. Histopathological examination displayed cuboidal and columnar cells, arranged as glands, trabeculae and solid sheets. Neuroendocrine differentiation was revealed by immunohistochemical staining with polyclonal antibodies against neuron specific enolase and chromogranin antigens.- - - - - - - - - - ranking = 2keywords = gland (Clic here for more details about this article) |
5/113. Benign glandular peripheral nerve sheath tumor of the seventh and eighth cranial nerve complex.A unique, deep-seated, benign, glandular peripheral nerve sheath tumor (PNST) of the cerebellopontine angle is described. The tumor arose from the seventh and eighth cranial nerve complex in a 15-year-old boy without neurofibromatosis. Histologically, benign glands were embedded in a bland spindle cell stroma. The epithelial cells were immunoreactive for CAM 5.2, and focally for chromogranin. The spindle cells were positive for S100P. The benign glandular PNST unassociated with neurofibromatosis is a controversial entity. The superficial location of most reported cases has made it difficult to exclude entrapped adnexae as a source for the glands. This tumor was separate from the internal auditory meatus on MRI scan, the most likely source of entrapped glands at this site. This case is the first report of a deep-seated, benign, glandular peripheral nerve sheath tumor. It suggests that glandular differentiation in PNSTs, while unusual, is not synonymous with neurofibromatosis or malignancy.- - - - - - - - - - ranking = 11keywords = gland (Clic here for more details about this article) |
6/113. Metastasizing mixed tumor of the parotid: initial presentation as a solitary kidney tumor and ultimate carcinomatous transformation at the primary site.Benign mixed tumors of the salivary glands are generally regarded as indolent and harmless neoplasms. A subset of benign mixed tumors, however, can undergo carcinomatous transformation (that is, carcinoma ex-mixed tumor). Even more rarely, a mixed tumor that is seemingly benign at the microscopic level will metastasize like a true carcinoma (that is, metastasizing mixed tumor [MZMT]). Despite the benign appearance of the metastatic implants, there is usually little doubt regarding their true nature and origin. patients invariably have had a mixed tumor removed from the parotid or some other salivary gland, and metastatic spread is usually preceded by multiple episodes of local tumor recurrence. We report a case of MZMT that presented as a solitary kidney mass. In the absence of a previous or concurrent salivary gland tumor, its metastatic nature was not appreciated and it was regarded as an unusual but benign kidney adenoma. One year after removal of the kidney mass, the patient presented with signs and symptoms of an aggressive parotid tumor. Pathologic examination of the tumor in the parotid demonstrated a high-grade carcinoma arising from a mixed tumor. This case underscores the importance of considering MZMT when a seemingly benign mixed tumor is encountered at a nonsalivary site, even in patients without a supportive history. Failure to do so may cause an unnecessary delay in primary tumor diagnosis and management, allow the primary tumor to progress toward a more malignant phenotype, and deny the patient a high expectation for a complete cure.- - - - - - - - - - ranking = 3keywords = gland (Clic here for more details about this article) |
7/113. Histomorphometric characteristics and cellular kinetics of colorectal polyps with epithelial serrated proliferation adjacent to carcinoma.Four cases of colorectal polyps with epithelial serrated proliferation (CP-ESP) with malignant transformation were studied. In CP-ESP adjacent to carcinoma, if the nuclear size in the surface layer was significantly smaller than those in the bottom and the middle layers of the crypts, the specimen was defined as zone formation positive. If there was no significant difference among the layers, the specimen was defined as zone formation negative. Cell kinetics were evaluated using Ki-67 immunostaining. The CP-ESP regions of cases 1 and 2 showed zone formation with inferior and lateral glandular branching, and were qualitatively hyperplastic on cell kinetics. Cases 3 and 4 showed inferior and lateral glandular branching with no zone formation, and were kinetically neoplastic (adenoma). The histogenesis of hyperplastic polyps with atypia (cases 1 and 2) involves the hyperplastic polyp-carcinoma sequence. In contrast, the development of tubulovillous adenoma or serrated adenoma (cases 3 and 4) may involve the tubulovillous adenoma-carcinoma or serrated adenoma-carcinoma sequence.- - - - - - - - - - ranking = 2keywords = gland (Clic here for more details about this article) |
8/113. Sebaceous carcinoma with apocrine differentiation.A 54-year-old male had a dome-shaped and skin-colored nodule on his nose. Histopathologically, we diagnosed this neoplasm as a low-grade sebaceous carcinoma rather than a sebaceoma based on the scanning magnification and cytology. This low-grade sebaceous carcinoma was associated with glandular structures. We regarded the glandular structures as those of apocrine glandular differentiation based on 1) the histopathologic features of the glandular structures formed by columnar luminal cells with evidence of decapitation secretion; 2) the expression of cytokeratin (CK) 19, CK8, CK8/18, and CK7 in the luminal cells; 3) the positive reaction of carcinoembryonic antigen and epithelial membrane antigen on the luminal surface and in the cytoplasm of the luminal cells; and 4) the common embryologic origin of the folliculosebaceous-apocrine unit. We found CK15 expression in undifferentiated cells within the mantles of normal hair follicles, suggesting that sebaceous stem cells might exist in mantles as follicular stem cells exist in bulge areas. pluripotent stem cells in the folliculosebaceous-apocrine unit can give rise to follicular stem cells, sebaceous stem cells, and apocrine stem cells. Our patient's neoplasm showed apocrine glandular differentiation and partial immunohistochemical positivity for CK15 in the neoplastic aggregations. We believe this neoplasm originated from pluripotent stem cells destined to become sebaceous stem cells or from sebaceous stem cells, which also have the ability to differentiate within apocrine glands.- - - - - - - - - - ranking = 6keywords = gland (Clic here for more details about this article) |
9/113. Dedifferentiation of adenoid cystic carcinoma: report of a case implicating p53 gene mutation.Adenoid cystic carcinoma is an indolent tumour with an unfavorable long-term prognosis. Dedifferentiation of adenoid cystic carcinoma, which is associated with an accelerated clinical course, has recently been described. We report a case with immunohistochemical and molecular workup to elucidate the likely mechanism of dedifferentiation. The patient, a 64-year-old woman, developed dedifferentiated adenoid cystic carcinoma of the submandibular gland ab initio, accompanied by cervical lymph node metastasis. Histologically, the low-grade adenoid cystic carcinoma merged gradually into an extensive dedifferentiated component that was composed of solid sheets and cords of anaplastic tumor cells with focal gland formation. Immunohistochemically, the dedifferentiated component, but not the adenoid cyst carcinoma component, showed strong overexpression of p53 protein and cyclin d1, as well as a higher Ki67 index. Molecular study confirmed the presence of p53 gene mutation selectively in the dedifferentiated component, suggesting a pivotal role of p53 gene alteration in the dedifferentiation process of adenoid cystic carcinoma.- - - - - - - - - - ranking = 2keywords = gland (Clic here for more details about this article) |
10/113. adenocarcinoma arising in a retained esophageal remnant.Fistulation between the trachea and an infected mucocele arising from an excluded retained esophageal segment is an interesting and unusual complication of esophageal bypass surgery. We present such a case in which there was also malignant transformation in the cyst wall, manifested by invasive adenocarcinoma and widespread high-grade glandular dysplasia.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
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