Section V. THE LEUKEMIAS
a. Leukemia is an abnormal, uncontrolled proliferation of one or more of the
white-cell-producing cells. It is a disease of the blood-forming tissues that always
involves the bone marrow.
b. The condition was first discovered microscopically by Donne in 1839 but was
not recognized as a clinical entity until 1845. Leukemia was commonly called "white
blood" because in many cases, the number of leukocytes in the peripheral blood was so
great that upon separation of the blood elements, the buffy (or white cell layer) might be
ten times greater than normal.
Leukemia occurs at any age. Often during the first five years of life, and until the
age 21, the great majority of cases are acute. From this time until around 45 the tide
turns and chronic granulocytic leukemia becomes the predominating form. It is much
more difficult to ascertain the relative frequencies of the various forms of acute
leukemia. One school of thought is that acute lymphoblastic leukemia predominates in
childhood until about the age of puberty and approximately equals the sum of the cases
of myeloblastic and monocytic; that monocytic leukemia never occurs in the aged; or
that chronic leukemia is never found in children.
a. The leukemias are classified by the duration of the disease; by the number of
white cells present in the peripheral blood; and by the predominant cell type found in the
peripheral blood and bone marrow. On the basis of disease duration, leukemia may be
Acute leukemia, a rapidly progressive disease that lasts several days to
Sabacute leukemia; 2 to 6 months.
(3) Chronic leukemia; the length of this disease is variable, depending on
the age of the patient and the type of cell involved. Most patients live a minimum of 1 to
2 years or more.
b. On the basis of the leukocyte count in peripheral blood, the leukemias are
Leukemic leukemia; white blood count is greater than 15,000.