Rectal varices due to chronic inferior mesenteric vein thrombosis caused by external compression in a large hiatus hernia containing the pancreas

A 79-year-old woman presented with a large fresh rectal bleed. Computed tomography revealed that she had a large type IV hiatus hernia, which contained the stomach and pancreas. Compression of the inferior mesenteric vein and splenic vein had led to thrombosis within these vessels and retrograde flow within the inferior mesenteric vein. This had led to the formation of portosystemic rectal varices. Ectopic varices occasionally form in the rectum, often in the context of liver cirrhosis. At the time of writing, ours is the first reported case of portosystemic rectal varices formulated in response to obstruction of vessels within a hiatus hernia.

Fibromatosis: benign by name but not necessarily by nature

Aggressive fibromatoses, also known as desmoid tumours, are rare fibrous tissue proliferations with a tendency for slow, local infiltrative growth. There is an association with Gardner's syndrome and familial adenomatous polyposis. Histologically they are fairly bland with no abnormal mitoses or necrosis. They do not metastasize, but can cause significant morbidity through their locally destructive effects. Magnetic resonance imaging is the method of choice for diagnosis, pre-treatment planning and post-treatment follow-up. Surgical excision with a wide margin is the treatment of choice. However, there is a tendency for local recurrence and repeated excision may result in a poor functional or cosmetic outcome. Radiotherapy is used to reduce local recurrence rates after excision and is also used to treat inoperable tumours. Long-lasting remissions can be obtained. Treatment is now planned using modern three-dimensional conformal techniques, similar to those used in soft tissue sarcoma management. There is no definite dose-response relationship, but doses of 50-60 Gy in 1.8-2 Gy fractions are recommended. Systemic therapy has been used for lesions not controlled by surgery or radiotherapy, or less commonly, as a primary treatment. Tamoxifen and non-steroidal anti-inflammatory agents are used most often as they are relatively non-toxic, but there is limited experience with cytotoxic chemotherapy and biological agents. There are no randomised trials to help guide the management of this locally aggressive 'benign' tumour and treatment decisions are best made by the local soft tissue sarcoma multidisciplinary team.

Dietary fat type and level influence adiposity development in obese but not lean Zucker rats

The development of obesity is influenced by a variety of factors including genetics and dietary fat type and level. To examine the interaction between these factors, male lean and obese Zucker rats (5 weeks initial age) were fed either a low-fat (15% calories) or one of two high-fat diets (65% calories; predominant fat source of either soybean oil or palm olein) for 8 weeks. Body weight, food intake, indirect calorimetry, and body composition determinations were performed. As expected, food intake, body weight, feed efficiency, oxygen consumption, heat production and carcass lipid were all significantly higher in obese compared to lean rats. Dietary fat level and/or type influenced body weight gain, oxygen consumption, heat production, energy balance, and carcass weight and lipid content in the obese but not in the lean Zucker rats. Oxygen consumption and carcass weight were increased approximately 25% and 10% respectively in obese rats fed either of the two high-fat diets as compared to those fed the low-fat diet. The type of fat fed in the high-fat diets also influenced body weight gain, heat production, energy balance, and carcass lipid content of the obese rats. Body weight gain and carcass lipid content were increased (16%-17%; P < 0.005) in obese rats fed the high-fat palm olein diet as compared to those fed the low-fat diet. These parameters were not increased in obese rats fed the high-fat soybean oil diet. In contrast, indirect calorimetry measurements indicated a moderate increase in heat production (Kcal/effective body mass/day; 14.5%) and decrease in energy balance (44.8%) in the obese rats fed the high-fat soybean oil diet as compared to those fed the low-fat diet. Energy expenditure and lipid accumulation were negligibly influenced by dietary fat level or type in the lean Zucker rats. The differential response of the lean and obese Zucker rats to this short-term dietary manipulation demonstrate that genetic background can influence an individual's response to dietary fat type and level. The genetically obese Zucker rat appears to be a good model for further studies of high-fat diet-induced obesity.

Adipose tissue expansion and the development of obesity: influence of dietary fat type

Recent studies indicate that the prevalence of obesity in adults has increased by 30% or more in the past decade, with increases in both genders and in all ethnic and racial populations and age groups. Obesity is associated with many chronic diseases and alterations in physiologic function including cardiovascular disease, hypertension, diabetes mellitus, gallbladder disease and certain types of cancer. Much attention regarding dietary influences on obesity development or prevention has focused on high fat diets. Many studies have confirmed that high fat feeding leads to an expansion of adipose tissue mass through an increase in fat cell size and/or number and to the subsequent development of obesity. However, there is little definitive information on the effect of type of dietary fat, especially palm oil, on adipose tissue cellularity and the development of obesity. These studies were designed to determine whether dietary fat of different sources vary in their ability to produce obesity and to begin to elucidate the mechanism by which such divergence occurs. Male Osborne-Mendel rats were fed either a low fat (15% calories) or one of three high fat diets (65% calories) for 12 weeks. The predominant fat source in the high fat diets was either soybean oil, tallow, or palm-olein (a fraction of palm oil). Final body weight was not influenced by fat level or type; however, percent carcass lipid and fat pad weight were higher in soybean oil and tallow fed rats than in low fat and palm-olein fed rats. Fat pad specific increases in cell size and cell number were observed for tallow and soybean oil fed compared to low fat and palm-olein fed rats. Serum triglycerides were higher in the tallow and palm-olein fed rats compared to low fat fed rats; no significant effects of dietary fat type on serum cholesterol were observed. These results indicate that palm-olein, unlike tallow and soybean oil, were comparable to a low fat diet concerning fat pad weight, body composition and adipose tissue cellularity when fed for twelve weeks as 65% of energy intake. The lower fat storage in the palm-olein fed rats is perhaps associated with a slower rate of triglyceride uptake and/ or a reduced fat cell proliferative capacity. The influence of dietary fat type on the proliferative capacity of the pre-adipocytes and on the production of a local or systemic adipogenic factor is being determined in subsequent studies.