UC has become more common since the 1950s.The geographic distribution of UC and Crohns disease is similar worldwide, with the highest number of new cases a year of UC found in Canada, New Zealand and the United Kingdom. The disease is more common in North America and Europe than other regions. In general, higher rates are seen in northern locations compared to southern locations in Europe and the United States. UC is more common in western Europe compared with eastern Europe. Worldwide, the prevalence of UC varies from 2 - 299 per 100,000 people. Together, ulcerative colitis and Crohns disease affect about a million people in the United States.As with Crohns disease, the rates of UC are greater among Ashkenazi Jews and decreases progressively in other persons of Jewish descent, non-Jewish Caucasians, Africans, Hispanics, and Asians. Appendectomy prior to age 20 for appendicitis and current tobacco use are protective against development of UC. However, former tobacco use is associated with a higher risk of developing the disease. United States
As of 2004, the number of new cases of UC in the United States was between 2.2 and 14.3 per 100,000 per year. The number of people affected in the United States in 2004 was between 37 and 246 per 100,000. Canada
In Canada, between 1998 and 2000, the number of new cases per year was 12.9 per 100,000 population or 4,500 new cases. The number of people affected was estimated to be 211 per 100,000 or 104,000.
Acute erythrocyte leukemia is a rare form of acute myeloid leukemia (less than 5% of AML cases) where the myeloproliferation is of erythrocytic precursors. It is defined as type "M6" under the FAB classification. Signs and symptoms
The most common symptoms of AEL are related to pancytopenia (a shortage of all types of blood cells), including fatigue, infections, and mucocutaneous bleeding. Almost half of people with AEL exhibit weight loss, fever and night sweats at the time of diagnosis. Almost all people with AEL are anemic, and 77% have a hemoglobin level under 10.0 g/dl. Signs of thrombocytopenia are found in about half of people with AEL. Causes
The causes of AEL are unknown. Prior to a 2008 reclassification by the World Health Organization, cases that evolved from myelodysplastic syndromes, myeloproliferative neoplasms, chemotherapy for other cancers or exposure to toxins were defined as secondary AEL. These cases are now likely to instead be classified as acute myeloid leukemia with myelodysplasia-related changes or therapy-related AML. +

Diagnosis
Acute erythroid leukemias can be classified as follows:

M6a (Erythroleukemia)
50% or more of all nucleated bone marrow cells are erythroblasts, dyserythropoiesis is prominent and 20% or more of the remaining cells (non- erythroid) are myeloblasts. M6b (Pure erythroid leukemia)
In rare cases the erythroid lineage is the only obvious component of an acute leukemia; a myeloblast component is not apparent. The erythroid component consists predominantly or exclusively of proerythroblasts and early basophilic erythroblasts. These cells may constitute 90% or more of the marrow elements.