1/101. Renal adenomatosis associated with carcinoma of the lower urinary tract: a case report with immunohistochemical study.A case of renal adenomatosis of the left kidney associated with a carcinoma of the ipsilateral ureter in a 49-year-old man is examined. One hundred and eight adenomas, which were smaller than 15 mm in diameter, and a single microcarcinoma, which measured 1 mm in diameter, were found in the kidney. Further, there were more than 800 hyperplastic lesions which could be classified into three groups: (i) 792 of distal origin; (ii) 24 of proximal origin; and 10 of collecting duct origin. The serial sections obtained from 19 paraffin blocks were stained using Leu M1 as the proximal marker and epithelial membrane antigen (EMA) as the distal/collecting marker to assist in determining the origins. Ten of the small adenomas (15 lesions), which did not exceed 3 mm in diameter, were predominantly positive for EMA and five were predominantly positive for Leu M1. Further, hyperplastic lesions of distal and collecting duct origins were diffusely positive for EMA and sporadically positive for Leu M1. The lesions of proximal origin were predominantly positive for Leu M1 and sporadically positive for EMA. These findings suggest that a progression from hyperplasia and a direct transition from a single tubule to adenoma occurred multifocally in different segments of the nephrons throughout the left kidney.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
2/101. Primary liver carcinoma complicating membranous obstruction of the inferior vena cava.A rare autopsy case of primary liver carcinoma complicating a pre-existing, incomplete membranous obstruction of the inferior vena cava (MOVC) is reported. The patient, a 67-year-old Japanese male, was admitted to hospital following a 2 year illness of a left chest wall tumor and a 3 month illness with progressive abdominal pain. Computed tomography scans of the abdomen displayed space-occupying lesions in the third and seventh hepatic segments, respectively. One month later, the patient developed edema of the lower extremities and marked venous dilatation of the abdominal trunk. At that time, Doppler examination revealed the presence of intrahepatic large venovenous collaterals. The patient subsequently succumbed 82 days after hospitalization. At subsequent autopsy, the inferior vena cava was completely obstructed by tumor thrombus, which was formed caudally and cranially to a thin membrane and mimicked the valve, with calcification and elastic lamina, at the phrenic portion. Intrahepatic large collateral pathways were found between submembranous and supramembranous hepatic veins. Anomalous absence of the ostia of the middle hepatic vein was found. In addition, the portal venous trunk was occluded by tumor thrombus. histology of hepatic tumors revealed a combined hepatocellular and cholangiocellular carcinoma in the non-cirrhotic liver with severe acute centrilobular congestion. In MOVC patients such as the case presented, malignancy-induced thrombosis was deemed to be an important factor in prognosis.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
3/101. Initiation of ectopic epithelial calcification in a calcifying odontogenic cyst.Ultrastructural observation was performed on a calcifying odontogenic cyst (COC) associated with an odontoma and arising in the right mandibular region of an 8-year-old Japanese boy. Four types of cells were identified in the epithelial layer of the COC. The basal cells were low columnar in shape and contained some intracellular organelles. They were attached to the neighboring cells with a few desmosomes and resembled inner enamel epithelium of the normal enamel organ. The stellate reticulum-like cells, polygonal in shape, possessed desmosomes and many cytoplasmic projections. Some intracellular organelles and a few bundles of tonofilaments were observed in the cytoplasm. The light oval cells that were pale staining with toluidine blue contained dilated membranous organelles and many relatively evenly distributed tonofilaments. These cells were usually scattered in the vicinity of the focal accumulations of ghost cells, and the cell membrane was discontinuous in parts. The ghost cells contained many bundles of tonofilaments that were 60-240 nm in diameter and arranged in various directions. No intact intracellular organelles were noted in the cytoplasm. They were attached to the neighboring ghost cells with some desmosomes and their cell membrane was discontinuous in parts. A variety of vesicles, 90-450 nm in diameter, were scattered among the tonofilament bundles. Some of these contained needle-like crystals that were considered to be initial calcification sites in ghost cells. These vesicles presented morphological similarities to matrix vesicles, and it is therefore suggested that matrix vesicle-like structures are deeply involved with initiation of calcification of ghost cells in COC.- - - - - - - - - - ranking = 2keywords = membrane (Clic here for more details about this article) |
4/101. Fine structure of a radiation-induced osteogenic sarcoma.An osteogenic sarcoma arose in the right orbit of a 7-year-old boy some 5 years after the right orbit had been treated by four courses of radiotherapy (total dose approximately 13,000 rads) for a multicentric retinoblastoma. death occurred 6 months after the orbital tumor was first detected. Study of the orbital tumor by electron microscopy revealed a cell population of varied morphology in which two main types were identified. In one group, the cells were large with radiolucent cytoplasm, which contained long branching segments of rough endoplasmic reticulum. In the second group, the cells were smaller with irregular nuclei and an electron-dense cytoplasm, which contained short segments of dilated rough endoplasmic reticulum and numerous mitochondria. The first group of cells closely resembled osteoblasts, while the second group had some features of osteoclasts or their percursors. The branching processes of the tumor cells were separated by an amorphous ground substance, which contained collagen-like fibrils and hydroxyapatite crystals. Crystal deposition was in some instances in close relation to extracellular membrane-bound vesicles.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
5/101. Double cancer - hepatocellular carcinoma and intrahepatic cholangiocarcinoma with a spindle-cell variant.Intrahepatic cholangiocarcinoma (ICC) with a spindle-cell variant is very rare. We report here a surgical patient who had double cancer - hepatocellular carcinoma (HCC) and ICC with a spindle-cell variant. In this 70-year-old man, who had a history of hepatic resection for HCC about 2 years previously, two large discrete masses were identified in the right lobe of the liver. A right lobectomy of the liver was performed. Pathological findings revealed that one tumor was a typical HCC, and the other was ICC with sarcomatous lesions. Immunohistochemical examinations of the sarcomatous lesions in ICC demonstrated that some of the spindle cells were positive for keratin, epithelial membrane antigen, and vimentin, but negative for S-100 protein, desmin, and actin. From these findings, we concluded that the sarcomatous lesions of ICC were not a true sarcoma, but sarcomatous transformation of cholangiocarcinoma cells, that is, a spindle-cell variant of ICC.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
6/101. Sinonasal teratocarcinosarcoma: ultrastructural and immunohistochemical evidence of neuroectodermal origin.The authors report a case of sinonasal teratocarcinosarcoma in a 37-year-old man, which was located in the anterior skull base and extended to the right nasal cavity and paranasal sinuses. The tumor was surgically resected twice, but it could not be removed completely. Microscopically, it was mainly composed of primitive cell nests within a moderately cellular stroma. The components of squamous cell epithelia with focal teratoid appearance and adenocarcinomatous differentiation were observed. There were many rhabdomyoblasts scattered in the nests and stroma. Ultrastructurally, the primitive cells had many neural processes with parallel microtubules, resembling olfactory neuroblastoma. Rhabdomyoblasts showed various degrees of skeletal muscle differentiation. Some of the stromal spindle cells had actin filaments with dense patches and dense core granules. Immunohistochemically, the primitive cells were positive for epithelial markers, neuron-specific enolase, synaptophysin, and myogenic regulatory proteins. The rhabdomyoblasts showed immunoreactivity for myoid markers, cytokeratin, epithelial membrane antigen, and synaptophysin. Most of the stromal spindle cells were positive for smooth muscle actin, neuron-specific enolase and synaptophysin. The immunohistochemical and ultrastructural findings suggest that primitive cells had the most primitive phenotype of placodes, and support the possibility that sinonasal teratocarcinosarcoma is essentially a neuroectodermal tumor with divergent differentiation.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
7/101. Old ectopic pregnancy remnants with morphological features of placental site nodule occurring in fallopian tube and broad ligament.Placental site nodule (PSN) is an asymptomatic benign proliferation of intermediate trophoblast from a previous gestation that failed to involute. It is most commonly found in the endometrium or endocervix; however, placental site nodule has recently been reported to occur at sites of ectopic gestation. This is the first case of PSN in the broad ligament in direct contact with the fallopian tube. The patient underwent surgery for an adenocarcinoma of the opposite tube. Microscopically and immunohistochemically, the lesion showed the characteristics of a proliferation of intermediate trophoblast.- - - - - - - - - - ranking = 17.171878429865keywords = ligament (Clic here for more details about this article) |
8/101. Differential diagnosis, prognostic factors, and clinical treatment of proliferative brenner tumor of the ovary.Brenner tumors are rare ovarian tumors displaying benign, borderline or proliferative, and malignant variants. The case of a 63-year-old woman with a proliferative brenner tumor is presented and the histomorphological differential diagnosis of this tumor entity is compared to that of its benign and malignant counterparts. light microscopy, immunohistochemistry, and electron microscopy were performed to allow discrimination from the other subtypes. Despite a considerable overlap of pathological features the differential diagnosis of proliferative brenner tumor could be established. Electron microscopy allowed assessment of characteristic infoldings of the nuclear membrane that proved to be a valuable ultrastructural criterion. Considering that the vast majority of Brenner tumors are benign, precise identification of the small proportion of malignant tumors allows the extent of surgical therapy to be adapted.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
9/101. Chromophobe renal cell carcinoma with sarcomatoid change. A case report.Chromophobe renal cell carcinoma (RCC) is a newly established entity of renal neoplasm with histological and molecular biological features different from those of common RCCs. Chromophobe RCC shows characteristically cloudy and reticular cytoplasm and cellular features resembling distal nephron. Its prognosis has been reported to be more favorable than that of common RCCs. Recently, however, several cases have been reported which showed sarcomatoid change to present poor prognosis. Here we present a case of chromophobe RCC with sarcomatoid change which was once resected surgically. The surgically resected tumor was histologically composed of chromophobe epithelial cell sheets and sarcomatoid elements. The former showed positivity for colloid iron staining, and was immunohistochemically positive for E-cadherin and epithelial membrane antigen (EMA), whereas the latter was positive for vimentin instead of colloid iron and E-cadherin. EMA was focally positive in the sarcomatoid element. The patient died with systemic metastases 14 months after the operation. Histologically, the metastatic tumors were composed only of sarcomatoid element lacking epithelial element. Based on these findings and previous reports, this case supports the existence of a tumor progression pathway from chromophobe to sarcomatoid RCC. It is necessary to perform careful postoperative investigation of chromophobe RCC due to its possible histological progression to the sarcomatoid subtype.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
10/101. 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 = membrane (Clic here for more details about this article) |
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