Cases reported "Adenoma"

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11/56. Metanephric adenoma and papillary carcinoma with sarcomatoid dedifferentiation of kidney. A case report.

    We present the case of a 74-year-old Caucasian male with an expansive process of the left kidney. No clinical and laboratory signs of polycytemia or hypertension were present. Microscopically, the spherical main tumor mass was composed of small basophilic cells arranged in longitudinal branching tubules typical of metanephric adenoma (MA). Another component, different from MA, was formed by a tumor in a papillary and tubopapillary arrangement. This component was diagnostic of grade 3 papillary renal cell carcinoma. The third component, which was merging with the papillary one, was composed of sarcomatoid, spindle cell carcinoma with prominent nuclear polymorphism and a high number of mitotic figures, including atypical mitoses. The sarcomatoid component filled the entire cortico-medullary space and infiltrated the surrounding non-neoplastic renal tissue, including the renal pelvis. Areas of necroses, hemorrhages, and mitotic figures were frequent. No structures of Wilm's tumor were seen in our case. One year after the excision, the patient is without recurrence and metastasis. The existence of the above mentioned tumor supports the hypothesis that metanephric adenomas and papillary renal cell carcinomas are interrelated lesions.
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12/56. adenomatoid tumor of the uterus: report of a case and review of the literature.

    A case of uterine adenomatoid tumor in a 47-year-old female was studied with both light and electron microscopes. The tumor was circumscribed, 2.5 cm in diameter, and located in the posterior wall of the uterus. In light microscopy, tumor cells showing "signet-ring" appearance arranged in cords or tubules. Hyaluronidase-sensitive acid mucopolysaccharide was present in the cells and luminal surfaces. Mucicarmine stain was negative and periodic acid-schiff reaction was faintly positive. In electron microscopy, the tumor showed basal laminae, well-developed desmosomes and numerous microvilli. Intercellular spaces were present between adjacent cells. Small intercellular spaces were separated from the large lumens by desmosomes and tight junctions, while large spaces communicated with the tubular lumens. Forty-four reported cases of adenomatoid tumor in females were briefly reviewed.
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13/56. An immunophenotypic comparison of metanephric metaplasia of Bowman capsular epithelium with metanephric adenoma, wilms tumor, and renal development: a case report and review of the literature.

    Metanephric metaplasia of the parietal epithelium of the bowman capsule is a rare pathologic finding of unknown pathogenesis that has occurred in patients with widespread malignant neoplasms of various types. We report this finding in a 25-year-old woman with partial expression of the Carney triad who died of a disseminated gastrointestinal stromal tumor, specifically a gastric stromal sarcoma. The metaplasia involved both kidneys diffusely. It originated in the parietal epithelium of the bowman capsule, extended into the proximal tubules, and focally surrounded the glomeruli in a semicircular manner Immunohistochemical analysis revealed that the cells of metanephric metaplasia expressed the wilms tumor gene product, bcl-2 protein, and CD57 and cytokeratin 7 and keratin AE1/AE3 focally, but not CD56. This immunophenotype parallels that of metanephric adenoma, wilms tumor, and nephrogenic rests and overlaps with antigen expression in certain periods of renal development.
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14/56. Syringomatous adenoma of the nipple: a case report.

    Syringomatous adenoma of the nipple is a rare disease. To our knowledge, only 23 cases have been reported in the literature. We present the case of a 36-year-old lactating woman with syringomatous adenoma of the nipple, in whom local excision of the tumor was performed. Histologically, the tumor consisted of tubules, ductules and epithelial cell strands, and most of the proliferating ducts showed a characteristic teardrop or comma-shaped appearance. Careful monitoring to detect local recurrence is considered necessary, because syringomatous adenoma of the nipple, while being benign, is a locally invasive tumor.
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15/56. Metanephric adenoma: case report and review of the literature.

    Metanephric adenomas are benign tumors frequently found post-mortem (from 7% to 22% of autopsies) which originate from distal tubules; they are generally small in dimensions (smaller than 1 cm) and located in the renal cortex. Etiology is unknown, even though they could be associated with smoke, tubular nephrosclerosis, dialysis. An endocrinal relationship was proposed, because of its more frequent incidence in female (2:1). Metanephric adenoma is an uncommon kind of renal adenoma with no malignant potentiality: from the clinical and diagnostic viewpoint its own greater importance depends on the probability of diagnostic misunderstanding with Wilms' tumor; furthermore its echographic, tomographic and arteriographic characteristics are often similar to small renal adenocarcinoma ones (100). Polycytemia is frequently associated to metanephric adenoma as paraneoplastic syndrome and, more rarely, abdominal mass, abdominal pain, hematuria and hypertension (140). The most important study on metanephric adenoma is the one realized by E.K. Mostofi, including 50 cases from the Department of Genitourinary pathology, Armed Forces Institute of pathology, washington, D.C., published in 1995; in this study half of findings was incidental; mean dimension of tumor about 5,5 cm and in 50% it could be seen a distinct capsule sourrounding the tumor (in the remaining cases the capsule was discontinuos or absent) (210). An important radiological characteristic is that metanephric adenomas are more frequent calcificated than other histotypes and, from the pathological viewpoint, the most important differential element seems to be the smaller dimensions of its cells with hyperchromatic nuclei in the absence or lack in mitotic activity and in the absence of chromosome aberrations. In the case of difficult histological diagnosis, cytogenetic and immunohistochemical analysis can be useful. In conclusion, because it is impossible to distinguish in the preoperatory between the metaneprhic adenomas and the other tumoral types on the bases of the symptoms, dimensions or radiographic appearance, it is mandatory to treat it as malignant eteroformations in a therapeutical strategy, when it is possible.
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16/56. Tubular adenoma of the gallbladder with squamoid spindle cell metaplasia. Report of three cases with immunohistochemical study.

    Three cases of tubular adenoma of the gallbladder with squamoid spindle cell metaplasia are reported. Two of the three patients, who were middle-aged Japanese, had a solitary polyp in the gallbladder, and the other had three polyps. All the lesions were detected incidentally by ultrasonography. The polyps were pedunculated with a fine or frail stalk, and ranged from 0.5 to 3.9 cm in diameter. Histologically, they were tubular adenomas accompanied by scattered foci composed of a compact collection of short-spindle or oval cells with mild atypia. These cells did not retain intercellular bridges, and lacked intracellular keratinization. Immunohistochemically, the spindle cells stained positively for high-molecular-weight cytokeratin (EAB 903, a marker of squamous cell differentiation), whereas adenoma cells lining the tubules were negative for this antigen. Therefore, the spindle cell component is considered to represent squamoid metaplasia of adenoma cells.
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17/56. Microcarcinoids in large intestinal adenomas.

    Composite adenoma-carcinoid tumors are rare colorectal lesions consisting of intermingled adenomatous and carcinoid components. Unlike other mixed endocrine-glandular colorectal neoplasms, which are generally malignant, their glandular component is histologically benign and their natural history is favorable. We present 4 cases of colonic adenomas containing microcarcinoids, a hitherto undescribed lesion that is either a precursor of composite adenoma-carcinoids or a related but independent entity. The cases, identified among our surgical and consultation files, were endoscopically routine sessile polyps removed from 4 otherwise normal individuals, 3 from the cecum and 1 from the distal colon. The microcarcinoids were 0.5 to 1.5 mm in size and situated within the basal lamina propria, where they interposed between the crypts and muscularis mucosae without disturbing the overall polyp architecture. Histologically, they consisted of collections of low-grade epithelial cells arranged in nests, cords, tubules, and irregular clusters and characterized by eosinophilic, granular, or clear cytoplasm and by round central nuclei with stippled or dusty chromatin. Endocrine differentiation of the microcarcinoids was confirmed by the expression of 3 or more of the following: Grimelius argyrophil, chromogranin, synaptophysin, neuron-specific enolase and somatostatin. No mitotic figures or MIB-1 or p53 positivity were observed. The glandular component of the polyps was unremarkable in 3 cases, but 1 polyp, in addition to a microcarcinoid, showed a diffuse pattern of mixed adenomatous-endocrine differentiation. The patients' clinical course was benign on the basis of 2 years' median follow-up (range, 6 mo to 10 y). Two patients with incomplete polypectomies underwent hemicolectomy revealing no residual endocrine neoplasia. awareness of microcarcinoids in colonic adenomas should help avert potential diagnostic pitfalls posed by their pleomorphism, basal location, and infiltrative patterns, and may help clarify their natural history and possible relationship to composite glandular-carcinoid tumors.
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18/56. Fine structural studies of a human thyroid adenoma, with special reference to psammoma bodies.

    The fine structural morphologic features of a microfollicular thyroid adenoma from a 28 year old female were examined. Although the patient had been laking exogenous thyroxine therapy for 14 months, the morphology of the adenoma was characterized by numerous small to medium sized follicles composed of metabolically active, well differentiated columnar cells with numerous colloid droplets, dilated granular endoplasmic reticulum, large numbers of coated vesicles and lysosomes, large colloid containing "lakes," microtubules, microfilaments, and prominent apical microvillous projections. Of special inetrest were small spherical psammomatous calcospherites ecountered in histiocytes and the interstitium. Also noteworthy were ropelike configurations observed in most of the follicular lumina. Structural-functional correlations and potential origins of psammoma bodies and calcospherites are discussed.
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19/56. Fine structure of a virilizing adrenocortical adenoma.

    An adrenocortical adenoma associated with adrenogenital syndrome in a two-year-old boy was investigated light and electron microscopically. Urinary 17-ketosteroid excretion was considerably elevated and unresponsive to dexamethasone administration. The level returned to normal after surgical removal of the tumour. Adenomatous cells display striking cellular and nuclear pleomorphism. Megalocytes with huge nuclei and nucleoli frequently occur. Deep cytoplasmic indentations cause nuclear pseudoinclusions and bizarre shape of the nuclei. True nuclear inclusions are also seen, as well as nuclear fragmentation. Cytoplasmic organelles show striking morphological alterations. mitochondria with lamellar and tubular cristae are transformed into round or ovoid organelles of vesicular type. Their internal compartment is reduced, matrix material increases relatively, and mitochondrial inclusion bodies develop. Mitochondrial inclusions are identified as corresponding to fuchsinophil (siderophil or argyrophil) granules seen in the light microscope. Their staining properties indicate their glycoprotein nature. Vesicular profiles of smooth endoplasmic reticulum predominate and stacks of rough endoplasmic reticulum are transformed into tubules and vesicles. In Golgi regions, only vesicular elements are enriched. Lipid droplets are scarce. It was not possible to demonstrate histochemically catalase activity in microbodies. Dense bodies only occur in small, undifferentiated tumour cells. multivesicular bodies, autophagosomes and residual bodies are rare. lipofuscin is absent. Tumour cells are thought to derive from a population of undifferentiated cells ("germinative tumour cells"). Their morphological features and organelle equipment during a hypothetical course of differentiation and following dedifferentiation is described and discussed with respect to exceeding androgen synthesis.
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20/56. Histiocytoid (epithelioid) hemangioma of the testis. The so-called vascular variant of "adenomatoid tumor".

    Adenomatoid tumors are well-recognized neoplasms generally considered to be of mesothelial derivation. We describe an unusual vascular neoplasm that arose in the testis of a 29-year-old and resembled an adenomatoid tumor by light microscopy. An orchiectomy was performed, and the patient is alive and disease-free 3 years later. The 2-cm tumor was composed of small tubules lined by mesothelial-like cells with uniform, vesicular nuclei. However, some lumina contained erythrocytes, and immunohistochemically, the luminal cells reacted with antibodies to vimentin, factor viii-related antigen, and ulex europaeus I lectin but not cytokeratin or epithelial membrane antigen. A cuff of muscle-specific actin-positive cells surrounded the luminal cell layer. This adenomatoid-like vascular neoplasm is more properly interpreted as a histiocytoid (epithelioid) hemangioma. Although some authors have considered microscopically similar lesions to represent a vascular variant of adenomatoid tumor, we prefer to reserve the term "adenomatoid tumor" for microscopically appropriate proliferations that have mesothelial features.
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