These usually start at the age of about 13 years in the distal segments of the colon and rectum. More and more polyps gradually appear till the age of about 20 years when the entire colon and rectum are involved.
It consists of pointed or blunt finger like processes of lamina propria covered by epithelium that shows branching. This type is often sessile than pedunculated. Majority of this lesion is more than 1 cm in size and in fact 60% of villous adenoma are over 2 cm in diameter.
It is the most common neoplasm of colon and rectum. This condition is rare in patients under 20 years of age. Its incidence increases as age advances and majority of patients are in the sixth decade.
Cholangiocarcinoma is a carcinoma arising from the small ducts or ductules, though carcinoma may occur in major hepatic ducts outside the liver substance.
These ulcers are associated with ‘erythrocyanosis frigida’, which is an exclusive disease of young women. These patients have thick ankles with abnormal amount of subcutaneous fat, combined with an abnormally poor arterial supply to the ankle skin.
These ulcers are caused by inadequate skin circulation. These occur in those parts of the limbs which are subjected to repeated pressure and trauma. Prolonged pressure on one part of the foot causes ischemic damage to the tissues and if the circulation is inadequate then the tissues cannot repair themselves and ischemic ulcer develops.
Sickle cell anemia is hereditary hemolytic anemia. This disease is characterized by presence of sickle and crescent shaped erythrocytes. The normal HbA that is adult hemoglobin is replaced by HbS that is abnormal sickle hemoglobin.
In thalassaemia the main defect is in hemoglobin polypeptide chain synthesis. Specific pairs of genes are responsible for synthesis of alpha, beta, gamma and delta chains of the hemoglobin molecules and deficiency of synthesis of one of these chains will lead to thalassaemia.
It is a hemorrhagic disorder characterized by subnormal platelet count in presence of bone marrow containing normal or increased megakaryocytes and in absence of any systemic disease.