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PubMed1990

Atypical metaplasia and incidence of bronchogenic carcinoma.

The prognostic implication of atypical squamous metaplasia of the respiratory tract has been uncertain, especially for mild atypia. The relation between degree of severity of atypical metaplasia as detected by sputum cytology and incidence of bronchogenic carcinoma was assessed among 14,414 men aged 45 years or older who smoked one or more packs of cigarettes per day. Trial participants underwent sputum cytologic evaluations every 4 months for an average of 7.4 years as part of the Cooperative Early Lung Cancer Detection Program of the National Cancer Institute and were followed for the development of lung cancer between 1971 and 1983 at three institutions: The Johns Hopkins University, the Memorial Sloan-Kettering Cancer Center, and the Mayo Clinic. Analysis with logistic regression controlling for age, race, occupational exposures to lung carcinogens, average number of cytology records per year, and smoking habits revealed that the estimate of the relative rate (RR) of developing bronchogenic carcinoma was greater among men who had mild atypia as compared with men who had negative cytology readings, but there were marked differences among institutions (RR = 1.1, 95% confidence interval (Cl) 0.8-1.5 at The Johns Hopkins University; RR = 1.6, 95% Cl 1.1-2.5 at the Memorial Sloan-Kettering Cancer Center; and RR = 2.5, 95% Cl 1.6-4.0 at the Mayo Clinic). Results suggest that mild atypia as detected by cytologic evaluation of sputum is an indicator of a modest elevation in risk of bronchogenic carcinoma.

Carcinoma, Bronchogenic↗
PubMed1996

Osseous metaplasia of the endometrium: a rare cause of infertility and its hysteroscopic management.

This case report presents a very rare and long-standing cause of infertility, osseous metaplasia of the endometrium, and describes its successful management by hysteroscopy. A woman with a history of induced abortion 12 years ago, failed to conceive from that time on. The infertility work-up was unrevealing except for the presence of intracavitary calcification on ultrasonography. After diagnostic hysteroscopy, solid bony spicules covering the posterior wall of the endometrial cavity were removed by wire loop resectoscope. Histology established the diagnosis of osseous metaplasia of the endometrium. The patient conceived in her second spontaneous cycle and has an ongoing pregnancy at the time of writing. Hysteroscopy was an effective means of extracting this heterotopic tissue, thereby re-establishing fertility even after a long period of infertility.

Adult↗
PubMed1989

Nature of so-called "metaplasia of the apocrine epithelium". Macrophages attack apocrine epithelium". Macrophages attack apocrine epithelium.

Immunohistochemical and electron-microscopic studies were performed on the lesion termed "metaplasia of the apocrine epithelium." which was seen in association with an apocrine adenocarcinoma. The cells of this so-called "metaplasia" lacked cytokeratin, which was present in the apocrine epithelium. Surprisingly, the lesion ultrastructurally consisted mainly of terminally differentiated macrophages, the cytoplasms of which were filled with numerous phagosomes and lipid droplets. The cells lacked a desmosomal connection at their borders and some had Langerhans granule-like structures in the cytoplasm. The luminal wall was often infiltrated with macrophages and lymphocytes, and, in some portions, was replaced by macrophages with a large cytoplasm filled with numerous phagosomes. The immunohistochemical and ultrastructural findings indicate that the lesion is not composed of cells of the apocrine epithelial origin, but of macrophages that have ingested apocrine epithelium.

Aged↗
PubMed1998

Synovial metaplasia in lipoma.

We present a unique case of a lipoma with widespread synovial metaplasia. A 52-year-old woman had a recurrence 1 year after excision of a subcutaneous lipoma of the neck. Histologically, the primary tumor was an ordinary lipoma. The recurrent tumor was a myxoid lipoma with synovial metaplasia. The synovial metaplastic process manifested as labyrinthlike clefts, which were lined by one or more synovial-like cell layers. Ultrastructurally, the synovial metaplastic cell had secretory, phagocytic, and fibroblastlike features.

Female↗
PubMed1979

Studies on end-stage kidneys. V. Unusual epithelial activity or remarkable endothelial metaplasia. Findings in a dialyzed kidney.

Tubule-like cells were found lining an artery and several arterioles and within the capillaries of infarcted glomeruli in one block of kidney from one of 54 cases of end-stage/dialysis kidneys. Three other blocks showed tubule-like structures within infarcted glomeruli and adjacent arterioles. Squamous metaplasia of remaining tubule epithelium was found in sections from four blocks of the same kidney. In two of these blocks, infarcted glomeruli had capillaries which were occupied by squamous cells. These findings are discussed as examples of metaplasia of the endothelium or alternatively as epithelial growth and invasion. The use of special stains and multiple blocks for this study seem to have been justified. These changes offer further evidence that the end-stage kidney after dialysis has unique alterations.

Adult↗
PubMed1983

Mucoepidermoid and squamous cell carcinomas of breast with reference to squamous metaplasia and giant cell tumors.

Clinical and pathologic features of five low-grade mucoepidermoid and a similar number of squamous cell carcinomas of breast are presented. Three of each were retrieved from 55 cases of invasive breast cancer previously assessed to exhibit squamous metaplasia. Although the estimated incidence of low-grade mucoepidermoid cancers is approximately 0.2%, they may be more frequent, masquerading under designations of squamous metaplasia or intracystic carcinomas. All patients with low-grade mucoepidermoid cancer, and the two recorded previously, were free of recurrence for 4-10 years. No high-grade mucoepidermoid cancers were found. Squamous cell cancers frequently have a phyllode configuration (carcinoma phyllodes). Two examined by electron microscopy revealed a commonality of ultrastructural features with similar tumors of other sites. None exhibited glandular differentiation or tinctorial evidence of mucin secretion. One squamous cell carcinoma contained both malignant epithelial and banal, osteoclast-like, stromal giant cells. Only the latter were identified in tissue culture. This experience and review of the literature prompted a nosologic characterization of giant cell lesions of breast. One patient with squamous cell carcinoma succumbed because of her disease; the remainder are either free of or alive with recurrence at 4 and 10 years.

Adult↗
PubMed1987

Synovial metaplasia of the skin.

Synovial metaplasia has been described in bone or soft tissues following surgical procedures or under experimental conditions. Three cases in which skin biopsies showed synovial metaplasia of the dermis are herein reported. The metaplastic foci were associated with cyst formation and transepidermal fistulae. All patients had a history of previous surgical procedures in the area, and in all, the lesions clinically resembled suture granulomas. Microscopically, the lesions bore a striking resemblance to hyperplastic synovium. The immunohistochemical studies showed strong staining with vimentin and scattered positivity with alpha-1-antichymotrypsin (alpha-1ACT) and lysozyme. No basement membrane antigens or elastic fibers were demonstrated. We believe that the name "metaplastic synovial cyst" is an appropriate pathologic designation for this entity. An increased awareness of its occurrence will help to establish its true incidence.

Adult↗
PubMed1988

Ciliated metaplasia in the gastric mucosa. In an American patient.

We report the first case of ciliated gastric metaplasia found in a Caucasian American patient. Cilia were found in cystically dilated glands underneath a gastric adenoma. The rarity of ciliated metaplasia among Caucasians and its high frequency among the Japanese suggests a difference in the gastric mucosa in the two populations.

Adenoma↗
PubMed1993

Mucous gland metaplasia of the prostate.

Mucous gland metaplasia of the prostate was observed in 11 of the 1,236 autopsy cases. The cells were characterized by plump cytoplasmic mucin and tiny nuclei that were basally oriented. They resembled Cowper's gland (bulbourethral gland) epithelium. The lesion was located randomly within the glands and was very small; only one was larger than 1 mm2. The cytoplasmic mucin was periodic-acid Schiff positive and immunohistochemically negative for prostate-specific antigen. Lectin binding profiles were different from those of normal prostatic glandular epithelium and also from those of Cowper's gland. The importance of recognizing mucous metaplasia lies in its differentiation from other lesions, especially from low-grade carcinoma.

Adult↗
PubMed1993

Pancreatic (acinar) metaplasia of the gastric mucosa. Histology, ultrastructure, immunocytochemistry, and clinicopathologic correlations of 101 cases.

The occasional finding within the gastric mucosa of unidentified epithelial cells with morphological features closely resembling those of pancreatic acinar cells has prompted us to investigate a retrospective series of 8,430 consecutive gastric biopsies and of 126 surgical specimens of gastric resection and total gastrectomy. The aims of the study were to morphologically and immunocytochemically characterize these cells, to define their actual prevalence in a large series of unselected cases, and to assess the clinicopathologic correlates of their occurrence. Pancreatic acinar-like cells characterized by abundant cytoplasm, which was acidophilic and finely granular in the apical and middle portions and basophilic in the basal compartment, have been identified in 101 cases (84 gastric biopsies and 17 gastrectomies). These cells, arranged in nests or in variably sized lobules among the gastric glands, were morphologically indistinguishable from pancreatic acinar cells, both by light and by electron microscopy. Furthermore, they were consistently immunoreactive for pancreatic lipase and trypsinogen and, in 75% of the cases, for pancreatic alpha-amylase. The appearance of these cells within the gastric mucosa was correlated significantly with chronic gastritis (p = 0.032) and with the simultaneous occurrence of intestinal and pyloric types of gastric metaplasia (p = 0.021). The findings indicate that this is a previously unrecognized pancreatic (acinar) metaplasia of the gastric mucosa, clinically and morphologically distinct from pancreatic heterotopia.

Adult↗
PubMed2001

Lipomatous meningioma: a clinicopathologic study of 18 cases with special reference to the issue of metaplasia.

We report 18 cases of lipomatous meningioma occurring in patients aged 14 to 79, most being females (72%). Sixteen were supratentorial and 2 involved the spinal meninges. Follow-up ranged from 1 to 120 months. Fifteen patients were cured with surgery alone and 3 (17%) experienced a recurrence at 7, 8 and 24 months. Of these, one died with disease 4 years after resection of the primary lesion. Histologically, 12 tumors were meningothelial, 3 transitional, 2 showed myxoid stromal changes and 1 was microcystic. The 2 spinal tumors were atypical. The proportion of fatty cells ranged from 10 to 90%. These resembled mature adipocytes or less commonly lipoblasts. Xanthomatous meningothelial cells were also noted in 6 tumors (30%). Both conventional meningothelial as well as lipid-laden cells exhibited epithelial membrane antigen immunoreactivity. In addition, occasional cells resembling mature adipocytes showed reactivity for S-100 protein. Ultrastructurally, lipidization of neoplastic cells varied from intracytoplasmic lipid droplets to a single massive globule. Moreover, lipid-laden meningothelial cells featured interdigitating cell membranes and well-formed desmosomes. Lipid droplets were not membrane-bound. In that metaplasia denotes differentiation of one mature cell type to another, lipid accumulation in meningiomas cannot be considered true metaplasia since their lipid-laden cells retain the immunophenotype and ultrastructural features of meningothelium. We suggest that this distinctive subset of meningiomas be termed "lipidized meningiomas" rather than being included in the metaplastic category.

Adolescent↗
PubMed2006

Ductal metaplasia in chronic lymphocytic thyroiditis as a manifestation of phylogenic regression to an exocrine structure.

From a morphologic and functional point of view the thyroid can be considered as both an exocrine and endocrine organ. Firstly, thyroglobulin is secreted at the apical pole of the thyrocyte. Secondly, after endocytosis thyroglobulin is lysed and T3 and T4 are secreted at the basal pole into the bloodstream. However, usually exocrine glands are constituted of 2 well separate components: an acinus/alveolar component and an exocrine duct component. Under particular conditions such as chronic injury the acinus/alveolar component is rapidly destroyed, whereas the ductal component seems to be far more resistant and can proliferate giving rise to a tubular network described as "ductulus reaction" or "ductal metaplasia." Normal exocrine ducts and metaplastic ducts exhibit common genetic and phenotypic features directly related to their tubular morphology. In this study, we describe in lymphocytic autoimmune thyroiditis the appearance of ductal-like structures which displayed the features of ductal metaplasia.

Exocrine Glands↗
PubMed1995

Synovial metaplasia of a periprosthetic capsule surrounding a polyurethane foam breast prosthesis.

A 43-year-old woman underwent two-stage bilateral reconstruction mammoplasty using silicone-filled, polyurethane foam-covered breast implants. The permanent implants were later removed. The periprosthetic capsule demonstrated synovial metaplasia by light and electron microscopy. Synovial metaplasia is believed to be induced by the physical and chemical characteristics of the prostheses and may have important clinical implications in reducing capsular contracture and increasing host acceptance of implantable biomaterials.

Adult↗
PubMed1983

Mucinous metaplasia of the endometrium: ultrastructural and histochemical characteristics.

The histologic, ultrastructural, and histochemical characteristics of a focus of mucinous metaplasia in the endometrium of a postmenopausal woman are described and compared with normal endocervical and endometrial epithelium. While, architecturally, the simple coiled metaplastic glands resembled endometrial glands, cytologically, they resembled endocervical cells in the ultrastructural appearance of the mucin, as well as in the histochemical-staining properties of the intracellular secretory product. The location of the focal area of metaplasia in the fundus, apparently isolated from endocervical mucosa, as well as its architectural resemblance to endometrium, indicates that it originates from endometrium rather than endocervix.

Endometrium↗
PubMed1992

Tubal metaplasia of the uterine cervix: a prevalence study in patients with gynecologic pathologic findings.

Tubal metaplasia (TM) of endocervical epithelium may be confused with endocervical dysplasia or adenocarcinoma in histologic or cytologic specimens. However, the potential magnitude of this problem is unknown, because the prevalence of endocervical TM in routine surgical pathology material is undefined. To determine the prevalence, distribution, and associated features of endocervical TM, we retrospectively reviewed a consecutive series of cone biopsy specimens (n = 82) and hysterectomy specimens in which the entire cervix had been sectioned (n = 26), obtained over 28-months. Tubal metaplasia was defined as epithelium containing all three cell types (ciliated, secretory, and intercalary) found in the normal fallopian tube. The mean patient age was 41 years (range, 21-79). Endocervical TM was present in 33 of 108 patients (31%) and was evenly distributed among all age groups. Its prevalence was related to the number of sections examined (23% of cases with less than or equal to 12 blocks of the cervix; 52% of cases with greater than 12 blocks; p less than 0.01) and was greater in hysterectomy than in cone specimens (62 vs. 21%, p less than 0.001). Although most frequent in the upper endocervix and in deep portions of glands, TM involved the surface in 36%, the superficial parts of glands in 64%, and the lower endocervix in 30% of positive cases. There was no association with phase of the menstrual cycle, inflammatory changes, or low-grade cervical intraepithelial neoplasia (CIN), but TM was inversely related to high-grade CIN in glands, presumably due to replacement of metaplastic cells by neoplastic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Association of endometrial epithelial metaplasias with endometrial carcinoma and hyperplasia in Japanese and American women.

We reviewed endometrial tissue from 166 cases of endometrial adenocarcinoma and hyperplasia--91 seen at Kyushu University, Fukuoka, Japan, and 75 at George Washington University, Washington, D.C., U.S.A.--to compare the prevalence of epithelial metaplastic changes in the two populations. Metaplasias were more common in the benign endometrium associated with carcinoma at George Washington University (78%) than at Kyushu University (54%). They were associated with carcinomas of lower grade and accompanied by hyperplasia at both institutions. These results indicate that endometrial metaplasias, like endometrial hyperplasias, tend to be associated with less virulent endometrial carcinomas and to be more common in American women (who represent a high-risk population for endometrial carcinoma) than in Japanese women (in whom the risk is low but rising.

Endometrial Hyperplasia↗
PubMed1996

Transitional (urothelial) cell metaplasia of the fallopian tube mucosa: morphological assessment of three cases.

The origin of rarely encountered transitional cell carcinomas of the fallopian tubes has, to date, been ascribed to transitional cell metaplasia of the tubal serosa or subserosal Walthard rests. We report here three examples of transitional cell metaplasia of the mucosa of the fallopian tubes--in each instance an incidental finding--and propose this lesion as a hitherto unreported possible precursor for such tumors.

Adult↗
PubMed1997

Transitional (urothelial) cell metaplasia of the uterine cervix: morphological assessment of 31 cases.

Thirty-one cases of transitional cell metaplasia (TCM) of the uterine cervix were studied. The mean age of patients was 62 years (range 30-87); 25 (81%) were postmenopausal and six premenopausal. In 24 of 25 postmenopausal patients, TCM was an incidental finding at operation for a variety of gynecological lesions, and in such patients the distribution of TCM included the endocervical canal, transformation zone, native ectocervix and vagina. In five of six premenopausal patients, TCM was identified in the cervices of women investigated for abnormal Papanicolaou smears. In all six premenopausal patients, as well as in the remaining postmenopausal patient who also presented with an abnormal Papanicolaou smear, TCM was confined to the endocervical canal and transformation zone. TCM was typified by a multilayer epithelium, clearly distinguishable from the atrophic ectocervical epithelium of most postmenopausal patients by its thickness (averaging 12 cells thick). TCM was identified on the surface epithelium or in sequestered endocervical glands resembling Walthard cell nests of the fallopian tube serosa. There was loss of the usual basal "picket fence" layer seen in cervical squamous epithelia; the cells had crowded nuclei oriented vertically and swirling to give a superficial appearance of disorder. Although lack of "differentiation" from the basal to superficial layers was characteristic, in many examples there was an obvious surface umbrella layer. Intraepithelial glandular differentiation and lesions resembling cystitis glandularis of the urinary bladder were occasionally noted on the ectocervix and vagina. Cellular detail included large pale oval nuclei, oriented vertically, with finely stippled chromatin, small inconspicuous nucleoli, and frequently a deep longitudinal groove. Although the nuclear/cytoplasmic ratio was high, cell-to-cell variation was negligible, and mitoses were rare and never atypical, which, with the nuclear details, distinguished TCM from high-grade squamous dysplasias. The nature of the metaplasia and its biological function are unclear. In postmenopausal patients, it presumably arises occasionally as a consequence of the altered hormonal environment of the cervix and vagina and is of interest only for the possibility of misinterpreting it as a high-grade squamous intraepithelial lesion. In premenopausal patients, it may represent a cellular variation of either physiologic or atypical metaplastic squamous epithelium of the cervical transformation zone.

Adult↗