Castleman's disease in the orbit of a 17-year-old girl: a case report.

Castleman's disease is an atypical lympho proliferative disorder comprising hyaline vascular elements, plasma cells, or a mixture of both, which can present in unicentric or multicentric fashion. Resection of unicentric lesions is typically curative, but multicentric disease, also characterized by constitutional symptoms and a poorer prognosis, often requires treatment with chemotherapy, radiation, steroids, or immune modulators. Castleman's disease is rarely diagnosed in the orbit. The authors present the clinical and histopathological findings of a 17-year-old who was found to have a focal lesion in her orbit. She was successfully treated with surgical resection and was free of disease recurrence or other sequelae at 10-months follow up.

Hyperhomocysteinemia and thrombosis: an overview.

CONTEXT: Homocysteine, a sulfur-containing amino acid, absent in natural diets, is a metabolic intermediary in transmethylation and transsulfuration reactions. Such reactions are essential to normal cellular growth, differentiation, and function. Excess homocysteine is associated with vascular disease and related disorders. OBJECTIVE: To review homocysteine metabolism, the pathogenesis and classification of hyperhomocysteinemia, and the published literature investigating the association of homocysteine and methylenetetrahydrofolate reductase defects with arterial and venous thromboembolism and related disorders. The role of vitamin supplementation in patients with hyperhomocysteinemia is addressed. DATA SOURCES: Published medical and scientific literature. Articles addressing the objectives were selected and reviewed. Pertinent studies and conclusions were summarized, grouped, and contrasted. CONCLUSIONS: The association of hyperhomocysteinemia and arterial and venous thrombosis is controversial. Severe hyperhomocysteinemia is associated with atherosclerosis. The effect of mild hyperhomocysteinemia is less certain. Coinheritance of methylenetetrahydrofolate reductase defects and factor V Leiden is likely to increase the risk of venous thromboembolism. The association of methylenetetrahydrofolate reductase defects combined with no additional thrombophilic risk factors with venous thrombosis is less clear. High doses of folic acid to lower homocysteine levels might not be necessary.

Novel in vitro perfusion model to study the interaction between coagulation and blood-borne metastasis.

The association between cancer and hemostasis has long been studied in cell culture, animal models, and cancer patients developing thrombosis. The variety of biologic mechanisms involved in malignancy and metastasis makes the understanding of the relative importance of each mechanism difficult. We have developed a novel in vitro perfusion model that allows for the isolated study of the interactions between tumor cells and components of the hemostatic system under normal physiologic conditions. Segments of denuded umbilical cord or saphenous vein are cut longitudinally and mounted in a perfusion chamber under sterile conditions. Human breast cancer cells are perfused for 24 h under venous flow conditions with either whole blood (WB), platelet-rich plasma (PRP), platelet-poor plasma (PPP), or serum. Tissue samples are fixed and stained with hematoxylin and eosin as well as with pan-cytokeratin. Morphometric analysis is performed to quantify cancer cell adhesion. With PRP, this model maintains normal human physiologic conditions for the duration of the experiment. It differentiates between previously characterized high and low metastatic breast cancer cell lines. In addition, different vein tissue types do not alter tumor cell attachment. This model appears to be an accurate representation of the pathophysiology of in vivo metastasis. This model may serve as a useful bridge between cell culture studies and animal models. It may be a useful tool to elucidate the role of selected hemostatic systems in blood-borne metastasis and may potentially serve as a screening tool for the development of antimetastatic pharmaceutical agents.

Splenic lymphoma arising in a patient with Gaucher disease. A case report and review of the literature.

Patients with Gaucher disease have an increased risk of malignancies, especially the lymphoreticular type. To our knowledge, this is the first reported case of Gaucher disease diagnosed during the workup and diagnosis of a splenic marginal-zone lymphoma with progression to diffuse large B-cell lymphoma. There are several theories as to how Gaucher disease leads to malignancies. The accumulated glucocerebroside in the reticuloendothelial organs, histologically visible as Gaucher cells, is thought to provide chronic antigenic stimulus to the immune system. Polyclonal hypergammaglobulinemia develops, and monoclonal populations of lymphocytes and plasma cells may arise from this premalignant proliferative state. How Gaucher disease is related to nonlymphoid malignancies remains unclear.