Acute panmyelosis with myelofibrosis (APMF) it is a poorly-defined disorder that arises as either a clonal disorder, or following toxic exposure to the bone marrow

Bone marrow

Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...

.

Presentation

Bone marrow biopsy shows abnormal megakaryocytes, macrocytic erythropoiesis, and defects in neutrophil production and fibrosis of the marrow (myelofibrosis).

Clinically patients present with reduction in the count of all blood cells (pancytopenia

Pancytopenia

Pancytopenia is a medical condition in which there is a reduction in the number of red and white blood cells, as well as platelets.If only two parameters from the full blood count are low, the term bicytopenia can be used...

), a very few blasts in the peripheral blood and no or little spleen

Spleen

The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...

 enlargement (splenomegaly

Splenomegaly

Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant of the human abdomen. It is one of the four cardinal signs of hypersplenism, some reduction in the number of circulating blood cells affecting granulocytes, erythrocytes or platelets in any...

).

Cells are usually CD34

CD34

CD34 molecule is a cluster of differentiation molecule present on certain cells within the human body. It is a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells...

 positive.

Prognosis and treatment

Median survival is about 9 months.

Autologous stem cell transplantation has been used in treatment.

Terminology

Controversy remains today whether this disorder is a subtype of acute myeloid leukemia

Acute myeloid leukemia

Acute myeloid leukemia , also known as acute myelogenous leukemia, is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells. AML is the most common acute...

 or myelodysplastic syndromes; however, it is currently classified as a form of AML.