1/15. 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 = tube (Clic here for more details about this article) |
2/15. Concurrent tubulovillous adenoma and transitional cell carcinoma associated with diffuse gastric and intestinal metaplasia of the defunctioned ureter.Villous adenoma is a common lesion of the gastrointestinal tract, but it is rare in the ureter. Thus, as far as we know, only one case limited to this location has been described. Intestinal metaplasia of the urothelium is not rare. However, only one case of gastric metaplasia with pseudopyloric glands has been described in the literature. We here report in detail on a tubulovillous adenoma of the ureter associated with diffuse gastric and intestinal metaplasia and a concurrent primary, solid, high grade transitional cell carcinoma, with extensive clear cell change, in a 56-year-old male patient. He had undergone a left nephrectomy for renal tuberculosis twenty years earlier, and the lesions developed in the ureteric stump. To the best of our knowledge, such a combination of lesions has not been reported previously either in the ureter or in the rest of the urinary tract. The coexistence of diverse lesions in our case might represent the pluripotentiality of the urothelium in association with chronic inflammation and neoplastic induction. The present report also emphasizes the metaplastic and malignant potential of a defunctioned urothelial structure. This case is of particular interest, because these coexistent lesions arose simultaneously with an anatomically separate adenocarcinoma of the rectum (Dukes' B). The patient died 76 days after admission. The dismal prognosis of our case was determined by the advanced anatomical stage and the histological high grade of the transitional cell carcinoma of the ureter.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
3/15. Melanotic oncocytic metaplasia of the nasopharynx: a report of seven cases and review of the literature.We describe seven cases of melanotic oncocytic metaplasia of the nasopharynx and review five other cases in the literature. It is usually a small, brown to black lesion that occurs around the eustachian tube opening, where abundant seromucinous glands and lymphoid tissue are present. Multiple or bilateral lesions are sometimes seen. All 12 reported cases are of Asian origin. Melanotic oncocytic metaplasia occurs predominantly in men (male:female=11:1), with a mean age of 68 years. Simple excisional biopsy appears to be curative. Microscopically, melanotic oncocytic metaplasia is a combination of oncocytic metaplasia of the epithelium of the gland and melanin pigmentation in its cytoplasm. Fontana-Masson staining and immunohistochemical staining of S-100 protein revealed numerous melanocytes with conspicuous dendrites in the glands and stroma, which probably transfer melanin to adjacent glands. The exact pathogenesis of melanotic oncocytic metaplasia is unknown, but we postulate that the lesion could be related to the oncocytic metaplasia of the seromucinous glands around the eustachian tube, which is followed by the local production and/or acquisition of the melanin pigment, under the influence of certain neuropeptides in the vicinity. The recognition of melanotic oncocytic metaplasia is of clinical importance, as it may be misdiagnosed as a malignancy to the unwary.- - - - - - - - - - ranking = 2keywords = tube (Clic here for more details about this article) |
4/15. Oncocytic metaplasia of the nasopharynx or extra-parotid Warthin's tumour?A case of oncocytic metaplasia obstructing the eustachian tube in an elderly patient is described. Histologically, it was similar to Warthin's tumour of the parotid gland. The lymphocytes were predominantly T cell, unlike those of Warthin's tumour which are predominantly B cell. It is proposed that oncocytic metaplasia represents an early stage in the evolution of Warthin's tumour.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
5/15. Metaplastic papillary tumor of the fallopian tube: a case report with ultrastructure.This is the fifth metaplastic papillary tumor of the fallopian tube identified in a postpartum tubal ligation. light microscopic studies demonstrate a mucinous metaplasia. The ultrastructure of this unusual papillary epithelial proliferation reveals abundant filaments with condensations. The tumor has not recurred during 4 years of follow-up.- - - - - - - - - - ranking = 1240.8682664869keywords = fallopian tube, tube (Clic here for more details about this article) |
6/15. Histogenesis of the broad ligament adrenal rest.broad ligament adrenal rests are well known. A case of adrenal rest external to the surface of the broad ligament and adjacent to the fallopian tube is reviewed, with specific emphasis on its histogenesis. The rest is associated with a foreign body, and it is suggested that it has arisen as a secondary development of celomic epithelial metaplasia.- - - - - - - - - - ranking = 248.17365329739keywords = fallopian tube, tube (Clic here for more details about this article) |
7/15. Barrett's esophagus: radiological and clinical considerations.We reviewed the radiographic findings in thirty patients with columnar-lined (Barrett's) esophageal mucosa. gastroesophageal reflux was observed in 90%, hiatal hernia in 83%, stricture in 80% and esophageal ulceration in 33%. Superficial nodular mucosal changes were detected on 50% of the air contrast esophagrams. Prominence of this pattern may be associated with dysplastic or early malignant change. In addition, four conditions associated with secondary lower esophageal sphincter incompetence were identified in our patient group. These were scleroderma, previous myotomy for achalasia, previous gastric surgery and long-term indwelling nasogastric tubes.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
8/15. Squamous metaplasia following necrosis of the adenohypophysis and of a chromophobe adenoma of the pituitary.Two cases of pituitary necrosis was presented, one occurring post partum in an otherwise normal gland, the other in a large chromophobe adenoma. In both cases the necrotic tissue became surrounded by squamous epithelial nests that developed through metaplasia from glandular cells of the adenohypophysis and adenoma cells respectively. The squamous elements were seen 6 days after the clinical events leading to pituitary necrosis in the first case and 20 days after pituitary apoplexy (hemorrhagic necrosis of an adenoma) in the second case. In contradistinction to the commonly found squamous nests which are usually located in the pars tuberalis and presumably develop through a slower process, the changes in the present two cases indicate that squamous metaplasia can develop quite rapidly at the margins of a necrotic process of the pituitary, either deep in the gland as in case 1 or occupying the entire circumference of a necrotic tumor as in case 2.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
9/15. Unsuspected intraperitoneal perforation of the urinary bladder as an iatrogenic disorder.Perforation of the urinary bladder associated with long-term indwelling catheter drainage is a rare and lethal iatrogenic disorder. Moreover, bladder perforation can occur in a variety of surgical settings. We report here several unusual situations: one in which a fibroid uterus probably played a role in pressure necrosis of a bladder with an indwelling catheter, one in which carcinoma of the prostate and faulty catheter drainage was present, and one in which pelvic radiation therapy was followed by bladder perforation. These three cases illustrate the clinical acumen required to recognize intraperitoneal perforation. The variety of presentations is suggested by the fact that one case was diagnosed preoperatively by cystogram, one was unexpectedly found at laparotomy for acute peritonitis, and one was discovered only at autopsy. One of the patients was diabetic, two had been treated for miliary tuberculosis, and all had a history of long-term urinary bladder catheterization. Bladder perforation can be prevented by several alternative methods of chronic bladder drainage. The diagnosis of the problem requires a high degree of clinical suspicion, aided by definitive cystograms. The treatment is surgical, including prompt repair of the perforation and drainage of the bladder.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
10/15. metaplasia of bone in lungs and bronchi: report of 2 cases.Two cases are reported of pulmonary osseous metaplasia in elderly men aged 91 and 64 years. The first case represented disseminated metaplastic bones occurring throughout the lungs. In the second instance, small foci of metaplastic bones were localized in some bronchial walls of the upper lobe of the right lung which had old treated tuberculosis, severe fibrosis, and bronchiectasis. Both cases also had advanced pulmonary emphysema and interstitial fibrosis. It is suggested that fibrosed interstitium of the lungs and bronchial walls has turned into bony metaplasia in both patients. However, osseous metaplasia from cartilage of the bronchial walls is additionally suggested in case 2. Multiple factors probably play roles in development of bony metaplasia.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
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