The Guidelines Project of the Associação Médica Brasileira (AMB) and of the Conselho Federal de Medicina (CFM) began in 2000 with specialist societies participating in the preparation of the texts. The guidelines are based on research and contain solid advice on the diagnosis, therapy, and prevention of diseases. Grounded in evidence-based medicine, they seek to answer specific or crucial questions regarding the disease. A review of the literature is performed and, using pre-established criteria, studies on the disease are selected and graded according to their characteristics and type. Randomized clinical trials and meta-analyses have the highest value (A). Second in importance are observational and clinical studies (B), then case reports and case series (C), and finally, publications of consensuses and opinions (D). Due to the methodology employed, current systematic reviews are clearly more relevant when compared to those written in the past. Historically, reviews were much more based on personal opinions and subject to the author's interest, that is, more concerned with the individual point of view and based on personal experience.1

The Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular (ABHH) began to participate effectively in the development of the guidelines of the AMB in 2009, with contributions by several experts as shown in Table 1; previously, the collection was limited, with fewer themes. After 2012, guidelines on several diseases were completed and published in the Revista Brasileira de Hematologia e Hemoterapia (RBHH); chronic myelogenous leukemia,2 multiple myeloma,3 and diagnosis4 and treatment of immune thrombocytopenic purpura.5 It is also important to quote other systematic reviews published in the RBHH, such as preventive practices in long-term hematopoietic stem cell transplantation survivors, with the participation of experts from several different countries.6 The consensus of the Sociedade Brasileira de Transplante de Medula Óssea (SBTMO) produced the famous 'Pink Book'; this was rounded out with two publications on transplantation in acute myeloid leukemia7 and autoimmune diseases.8

Acute promyelocytic leukemia (APL) has well-defined clinical, cytogenetic, and morphological characteristics; it encompasses 10% to 15% of all myeloid-type leukemias. Its molecular bases are well defined, with different variations influencing the treatment of patients.9 The results, as reported by the International Consortium on APL, established the treatment strategies and the conduct for the disease in developing countries.10,11

The guidelines for the diagnosis and treatment of APL12 are published in this issue of the RBHH, the first in 2014, thereby adding to those already published. Hopefully, this will stimulate other experts to continue this hard work, aiming to contribute to medical practice and to solidify the knowledge on the diagnoses and treatment of hematologic diseases.