<prompt> Answer this question truthfullyWhat is the natural history, prognosis, and potential complications associated with anaplastic large cell lymphoma?  <response>: <reason> Those with ALK positivity have a better prognosis. ALK-negative anaplastic large cell lymphomas represent other T-cell lymphomas in a final common pathway of disease progression. Overall better prognosis than other aggressive lymphomas. ALK-positive anaplastic large cell lymphoma is associated with a 5 year survival rate of 70-80. ALK-positive anaplastic large cell lymphoma is associated with a 5 year survival rate of 30-40.The I nternational P rognostic I index IPI is used to estimate the prognosis of patients. The IPI takes into account 5 variables:Patients age 60 years Elevated serum lactate dehydrogenase LDH Eastern Cooperative Oncology Group ECOG performance status Ann Arbor clinical stage III or IV Number of involved extra nodal sites 1If any of this criteria is met, one point is awarded for the IPI. The interpretation of the total score is as follows:0 to 1: Low risk 2: Low-intermediate risk 3: High-intermediate risk 4 to 5: High riskAccording to the International Peripheral T cell Lymphoma Project, the estimated 5-years survival for each of the IPI stages are as follows: Low risk IPI 0-1: 90 Low-intermediate risk IPI 2: 68 High-intermediate risk IPI 3: 23 High risk IPI 4-5: 33However, more recently, the International peripheral T-cell lymphoma Project score IPTCLP has demonstrated to be the most accurate score to predict overall survival in patients. This score includes:Age Eastern Cooperative Oncology Group ECOG performance status Platelet count 