Acute Di Guglielmo syndrome, M6
Acute erythroleukemia M6b subtype
Acute erythroleukemia M6a subtype
Acute myeloid leukemia FAB-M6
Acute myeloid leukemia M6
Acute erythroid leukemia or Di Guglielmo syndrome is a rare form of acute myeloid leukemia (less than 5% of AML cases where the myeloproliferation is of erythroblastic precursors. It is defined as type "M6" under the FAB classification. M6 or erythroleukemia is rare and difficult to diagnose. More than 30-50% of the nucleated marrow cells are abnormal nucleated red blood cells.
Erythroleukemia is predominantly a disease of adults. It comprises 5-6% of cases of AML. Pure erythroid leukemiais extremely rare and can occur at any age. Occasional cases of CML will transform in to AML-M6.
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.
Some of the symptoms of Leukemia, Erythroblastic, Acute incude:
- Respiratory symptoms
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.
Acute erythroid leukemias can be classified as follows:
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. Despite this lack of myeloblasts, these cases should be considered acute leukemias. In a WHO proposal the blastic leukemias that are limited to the erythroid series are designated pure erythroid malignancies.
M6c (Erythroleukemia and Pure erythroid leukemia):
Myeloblast- and proerythroblast-rich mixed variant.
Information on prognosis is limited by the rarity of the condition. Prognosis appears to be no different to AML in general, taking into account other risk factors. Acute erythroid leukemia (M6) has a relatively poor prognosis. A 2010 study of 124 patients found a median overall survival of 8 months. A 2009 study on 91 patients found a median overall survival for erythroleukemia patients of 36 weeks, with no statistically significant difference to other AML patients. AEL patients did have a significantly shorter disease free survival period, a median of 32 weeks, but this effect was explained by other prognostic factors. That is, AEL is often associated with other risk factors, like monosomal karyotypes and a history of myelodysplastic syndrome. Prognosis is worse in elderly patients, those with a history of myelodysplastic syndrome, and in patients who had previously received chemotherapy for the treatment of a different neoplasm.
Treatment for erythroleukemia generally follows that for other types of AML, not otherwise specified. It consists of chemotherapy, frequently consisting of cytarabine, daunorubicin, and idarubicin. It can also involve bone marrow transplantation.