Malignant Hemangiopericytoma Arising in Neurofibromatosis: A Case Report with Histological, Immunohistochemical and Ultrastructural Studies

Subject. A 27-year-old Hispanic male with clinical manifestation of neurofibromatosis type 1 developed chronic constipation and urination difficulty along with recently increased abdominal bloating and anorexia. He also noted 40 lbs weight loss over period of 1 year. Physical and radiographic examinations revealed a large mass in the right pelvic fossa

Primary malignant melanoma of the ovary arising in a cystic teratoma; case report and review of the literature

Primary malignant melanoma of the ovary arising in a cystic teratoma is extremely rare. There is no melanocytic component in the normal ovarian tissue. However, melanocytes may be present in a cystic teratoma of the ovary, especially at the basal layer of squamous epithelium. We report a case of primary malignant melanoma of the ovary arising in a cystic teratoma. We demonstrate junctional activity of melanocytes showing malignant transformation with both radial and vertical growth phases, a feature diagnostic for primary malignant melanoma but not always demonstrated in such cases. We compiled and reviewed twelve cases that are also able to demonstrate junctional activity

Eccentric Iliac Artery Stenosis: A Canine Model for Angioplasty

A canine model was developed to induce eccentric iliac artery stenosis. Lesions were induced by exposing the medial aspect of the right and left common iliac arteries in four animals to direct argon laser energy (LA). A 2.5-mm diameter side-firing laser probe was used to deliver 10 W of power in 5-s intervals. Twenty-five pulses were delivered over a 5-ctn length of artery with an approximate spot size of 0.8 mm2. Selected arteries (n = 2, LA + Ca) were injected in the same laser injury site with calcium chloride (10% solution). Injections were accurately accomplished using an angioscopically guided guidewire/needle device. In all cases, the internal elastic lamina was broken with focal disruptions of the media. At 9 and 14 days, the LA (n = 3) and LA + Ca vessels (n = 1) had minimal stenoses (< 5% area reduction). These vessels contained edematous media with replacement of necrotic smooth muscle by fibrous tissue. At 23 days, the LA (n = 1) and LA + Ca (n = 1) vessels contained 22% und 33% luminal reductions, respectively, with moderate neointimal proliferation and no evidence of calcification. At 56 days the LA vessels (n = 2) contained 30 and 42% luminal area stenoses with marked neointimal hyperplasia. This preliminary data suggests that controlled arterial wall injury with LA irradiation can induce eccentric fibrointimal lesions in a canine model

A Canine Iliac Artery Occlusion Model

This report describes an occlusive canine iliac artery model for use in experimental angioplasty procedures. Lesions were induced by overdistending and breaking the internal elastic lamina of the artery and implanting a 2-cm long occlusive collagen plug. The collagen plug diameter was varied to fit the iliac artery and caused immediate bilateral iliac occlusions. Histology of the lesions at 9 and 14 days (n= 2) showed that the lumen was filled with a mixture of fresh thrombus and collagen pad material (more collagen than thrombus) with focal disruptions of the internal elastic lamina. At 36 days (n= 2) the lumen was obliterated with a mixture of organizing thrombus and collagen pad material (more organizing thrombus than collagen). At 60 (n= 4) and 80 (n=8) days the collagen pad had been completely replaced with organizing thrombus consisting of collagen fibers and hemosiderinladen macrophages with persistent focal disruptions of the internal elastic lamina. These initial data demonstrate the ability to create fibrotic arterial occlusions in as short a time as 60 days and to provide a practical model to study methods for treating localized peripheral vascular occlusive disease