Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The development of estrogen-induced Leydig cell tumors in cryptorchid BALB/c mice was studied with the electron microscope. Changes in Leydig cell fine structure are apparent by 10 days after the s.c. implantation of a pellet of diethylstibestrol (DES). The smooth endoplasmic reticulum is diminished, and there is an increase in lipid droplets and free polysomes as compared with untreated cryptochid controls. These alterations persist as the Leydig cells proliferate to form focal areas of hyperplasia in the interstitial tissue. During this period of proliferation, activated macrophages containing large residual bodies appear among the Leydig cells. If DES treatment is continued for several months, malignant Leydig cell tumors, result. They are characterized by a nuclear and cytoplasmic pleomorphism of the Leydig cells and a decreased macrophage population. Virus-like particles are rarely seen within the cell during the period of tumorigenesis. Along with the reduction in smooth endoplasmic reticulum in the Leydig cells after DES treatment, evidence from the literature suggests that there is also a decrease in testosterone biosynthesis. However, it is not clear whether these two effect are correlated, since the level of the microsomal enzymes of steroid biosynthesis may vary independently of either the amount of smooth endoplasmic reticulum or the level of androgen secretion. The increase in lipid droplets seen in Leydig cells after DES treatment suggest the accumulation of precursors from the steroid biosynthetic pathway. The macrophages are though to represent scavenger cells, rather than a primary tumor cell population. The paucity of virus-like particles within altered Leydig cells implies that formed virus is not a prerequisite for tumorigenesis.
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PMID:Changes in fine structure accompanying estrogen-induced tumorigenesis of Leydig cells in the mouse testis. 23 24

The ultrastructural and immunohistochemical features of a primary tumor of the ileum showing the classic histologic features of an inflammatory fibroid polyp (IFP) of the gastrointestinal tract are presented. Ultrastructurally the proliferating cells showed a combination of fibroblastic and histiocytic features, with abundant rough endoplasmic reticulum and active production of collagen in many of the cells and long, dendritic cytoplasmic projections with large cytoplasmic vacuoles containing remnants of phagocytosed cellular debris in others. Immunohistochemical studies showed strong cytoplasmic positivity in the proliferating cells with vimentin antibodies and scattered positivity with muramidase. Additional findings include the ultrastructural demonstration of oligocilia and occasional primitive intercellular junctions. The findings in this case suggest that IFP may represent a proliferation of primitive submucosal stromal cells exhibiting incomplete fibrohistiocytic differentiation.
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PMID:Inflammatory fibroid polyp of the small intestine: ultrastructural and immunohistochemical observations. 218 50

We report a case of follicular thyroid carcinoma with clear cell change displaying unusual ultrastructural features. Light microscopy revealed a metastatic neoplasm in the 12th thoracic vertebra that was composed of nests consisting mainly of clear cells. The tumor was interpreted as a metastasis of a clear cell type of thyroid carcinoma, based on positive immunohistochemical staining for thyroglobulin. However, unlike the metastatic bone lesions, the primary tumor in the thyroid consisted mainly of neoplastic follicular cells with lightly eosinophilic cytoplasm. A distinct follicular formation was noted throughout the tumor. In a portion of the tumor, a solid or stratified disposition of the cells was also observed. The primary tumor contained only a few clear cells similar to those seen in the metastatic bone lesions. In addition, we noted a transition between the follicular cells and the clear cells. Thus, this neoplasm was diagnosed as a follicular thyroid carcinoma with clear cell change, but not a specific type of thyroid neoplasm. Electron-microscopic examination revealed that the cells corresponding to clear cells under light microscopy had abundant cytoplasm characterized by varying degrees of dilation of rough endoplasmic reticulum (RER), which might reflect increased synthesis, storage of secretory products, or both.
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PMID:Follicular thyroid carcinoma with clear cell change showing unusual ultrastructural features. 327 37

A case of adrenocortical carcinoma with feminization seen in a man aged 35, is reported. The levels of estron (E1) and estradiol (E2) in the venous blood draining the tumor were high, and it was confirmed by in vitro assay of tumor cells taken from the primary tumor of the left adrenal gland that the tumor produced estrone. The light microscopic examination demonstrated that the primary tumor was composed of mixture of large cells with pleomorphic nuclei and vacuolated cytoplasm and uniform cells with ovoid nuclei and eosinophilic cytoplasm. The electron microscopic examination on the latter cells revealed numerous large and irregularly shaped mitochondria with mostly tubular or lamellar and occasionally vesicular cristae and electron-dense matrix, well-developed smooth-surfaced endoplasmic reticulum in the cytoplasm. However, lipid droplets and lysosomes or lipofuscin granules were scanty. From these findings, it is suggested that cells of the present tumor have characteristics of those in the zona reticularis of the adrenal cortex as well as in the fetal cortex, and the functional property of this tumor is well correlated with its morphological features.
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PMID:Estrogen-producing adrenocortical carcinoma. A light and electron microscopic study. 646 58

The case of a 31-year-old man with a neck mass of 7 months' duration is described. An X-ray examination showed a tumor originating from the right greater horn of the hyoid bone that pushed the larynx and pharynx to the left. Upon visual inspection the tumor seemed to be cartilaginous in nature. Histologically it was a well-differentiated chondrosarcoma that originated from the periphery of the hyoid bone. Ultrastructural study demonstrated an abundant rough endoplasmic reticulum, a particularly well-developed Golgi apparatus, and pleomorphic microvilli. 10 months after excision, a local recurrence invaded the primary marrow spaces of the hyoid bone. A review of the literature indicates that the prognosis of this tumor is unfavorable and that the recurrence of hyoid bone chondrosarcoma generally is less differentiated than the primary tumor.
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PMID:Peripheral chondrosarcoma of the hyoid bone. Report of a case. 667 92

A 7000 g cystic tumor replacing the body and tail of the pancreas was resected in a 64-year-old man. Numerous peritoneal implants confirmed its malignant nature. Light microscopy of both the primary tumor and the implants revealed distinctive cytoplasmic eosinophilia and apical granules. Ultrastructural examination demonstrated numerous zymogen granules and abundant, rough endoplasmic reticulum, which confirmed that the tumor was composed of acinar cells. No mucinous or serous differentiation was detected. We have not found report of a similar tumor.
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PMID:Acinar cell cystadenocarcinoma of human pancreas. 745 28

The objective of this study was to examine the identity and characteristics of a spontaneously occurring murine retroperitoneal tumor of BALB/c mouse origin that selectively metastasized to the liver. From the primary tumor, a permanent cell line, termed LMFS (liver metastasis from sarcoma) was established in vivo and in vitro. After a subcutaneous injection of more than 1 x 10(5) cells in the side back of mice, the LMFS cells proliferated at the inoculation site (100% take) and induced metastatic nodules spontaneously in the liver, but not in the lung. By the limiting dilution technique, a cloned cell line, LMFS-1, was established in vitro. The LMFS-1 cell line had similar morphological characteristics to the LMFS cells both in vitro and in vivo. The doubling time of the LMFS-1 cell line was 10 h in passage 60. The number of chromosomes ranged from 71 to 108 and 93% of metaphases showed near-tetraploidy. In microscopic examination, no specific arrangement of the LMFS tumor cells was seen; the LMFS cell had medium- to large-sized atypical nuclei and clear and large cytoplasm. Electronmicroscopy showed that the cytoplasm of the LMFS cell had a moderate amount of rough-surfaced endoplasmic reticulum but no desmosomes or microvilli. Immunohistochemically, the LMFS cells were positive for vimentin, but showed no reaction for keratin or cytokeratin. Therefore, the LMFS tumor was considered to be an undifferentiated sarcoma. The LMFS cell line should be a useful tool not only for studies of metastasis, but also for experiments on the therapy of hepatic tumors.
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PMID:Establishment and characterization of BALB/c retroperitoneal sarcoma with spontaneous liver metastases. 822 80

A case of myofibrosarcoma of the breast is described. A 55-year-old woman presented with a small mammary nodule. A large recurrent lesions appeared a month later, and the patient died 11 months following initial presentation from diffuse pleuropulmonary metastases. Histologically, the primary tumor consisted mainly of spindled cells, arranged in fascicles and surrounded by varying quantities of dense hyaline collagen. The recurrent lesion had a more pleomorphic organization. In both lesions, there was positive immunostaining for vimentin, smooth-muscle actin, and fibronectin, and negative results for desmin, laminin, and type IV collagen. Electron microscopy revealed abundant rough endoplasmic reticulum, myofilaments with focal densities, and the fibronexus junctions and fibronectin fibrils characteristic of myofibroblasts. Given these cellular features and behavior, the tumor was interpreted as a malignant neoplasm showing myofibroblastic differentiation, i.e., a myofibrosarcoma. This case enlarges the group of myofibrosarcoma of breast, also with the demonstration of fibronexus and fibronectin fibrils. The paper emphasizes the criteria required for myofibroblastic differentiation and reviews lesions of the breast reported in the literature as myofibroblastic.
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PMID:Myofibrosarcoma of the breast: review of the literature on myofibroblastic tumors and criteria for defining myofibroblastic differentiation. 913 Sep 98

Malignant melanoma is known to display tremendous histologic diversity. One rare variant is the rhabdoid phenotype, so called because of the appearance of cells resembling rhabdomyoblasts seen in malignant rhabdoid tumors of the kidney. We present the histologic, immunohistochemical, and ultrastructural features of a malignant melanoma composed entirely of rhabdoid cells. A 62-year-old man presented with a 6.5-cm lung mass. Although presumed to be a metastatic lesion, extensive workup failed to reveal a primary tumor site. Histologic sections showed a mass composed entirely of polygonal neoplastic cells with prominent nucleoli and large hyaline cytoplasmic inclusions. The tumor cells were strongly immunoreactive with S100 protein, vimentin, and CD56, and were focally reactive with Mart-1. Tumor cells were negative for Melan-A, tyrosinase, HMB-45, AE1/AE3, cytokeratin (CK) 7, CK8/ 18, CK20, CK903, CAM 5.2, epithelial membrane antigen, smooth muscle actin, desmin, leukocyte common antigen, Bcl-2, CD3, CD20, CD30, CD138, kappa and lambda light chains, CD68, CD34, factor VIII, synaptophysin, and glial fibrillary acidic protein. Electron microscopy showed cytoplasmic whorls of intermediate filaments containing entrapped rough endoplasmic reticulum, mitochondria, and lipid. Recognition of this rare variant of malignant melanoma is important in the evaluation of tumors with rhabdoid morphology.
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PMID:Malignant melanoma with a rhabdoid phenotype: histologic, immunohistochemical, and ultrastructural study of a case and review of the literature. 1516 28

p53 is a critical tumor suppressor which removes cells with DNA damage by regulating expression and activity of a select group of p53-induced genes (PIG) that subsequently induce apoptosis. PIG8 was also identified as a gene induced by etoposide and named etoposide-induced gene 24 (EI24). Later experiments established EI24/PIG8 as a proapoptotic factor and suggested that it may function as a tumor suppressor. Indeed, EI24/PIG8 is relatively highly mutated in aggressive breast cancers and is located in a region which expresses frequent loss of heterozygosity. However, despite these important observations, the activity and role of EI24/PIG8 remain largely unknown. We used (immmuno)fluorescence microscopy and subcellular fractionation techniques to show that EI24/PIG8 is localized in the endoplasmic reticulum (ER). Pull-down experiments showed that it specifically binds with Bcl-2, a death regulator known to reside in mitochondria, ER, and the nuclear envelope. EI24/PIG8-Bcl-2 binding was corroborated by coimmunoprecipitation and other in vitro and in vivo protein-protein binding assays. Further analysis showed that EI24/PIG8 uses its N-terminal region to bind the BH3 domain in Bcl-2. Finally, we used immunohistochemical techniques to analyze expression of EI24/PIG8 in breast cancer tissue progression arrays and showed that loss of EI24/PIG8 is associated with tumor invasiveness but not with the development of the primary tumor. These results suggest that EI24/PIG8 is a novel, ER-localized Bcl-2-binding protein which may contribute to apoptosis by modulating the activity and/or function of Bcl-2 in this organelle. EI24/PIG8 may serve to prevent tumor spreading, consistent with its suspected role as a tumor suppressor.
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PMID:Apoptosis factor EI24/PIG8 is a novel endoplasmic reticulum-localized Bcl-2-binding protein which is associated with suppression of breast cancer invasiveness. 1578 22


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