Biology of Disease

joints and bones and a general feeling of malaise. Diagnosis is achieved by

microscopic examination of bone marrow taken from the pelvis or sternum.

A lumbar puncture may be used to obtain a sample of cerebrospinal fluid, to

detect the presence of leukemic cells.

Acute lymphoblastic leukemia is classified into three types according to the

FAB classification. These are L1ALL, in which the lymphoblasts resemble

mature lymphocytes, with L2ALL and L3ALL showing increasingly immature

forms of lymphoblasts. The disease may also be classified according to

whether the leukemic cells are T cells or B cells, or pre-B cells, which are

immature forms. A diagnosis of these forms involves histological examination

and immunofluorescence testing of cell surface characteristics, with analysis

by flow cytometry (Box 6.1 and Chapter 4). A proportion of ALL patients also

have the Philadelphia chromosome, which can be shown by karyotyping.

The treatment for ALL involves chemotherapy and this achieves remission

in 80% of patients. Chemotherapy may also require intrathecal injection

of chemotherapeutic agents (Section 17.7) to destroy leukemic cells in the

cerebrospinal fluid. Steroids, such as dexamethasone, may be combined

with cytotoxic drugs and imanitib may also be used. Radiation therapy to the

brain and the testes in men may also be required to prevent recurrence. When

patients are at high risk of relapse, a stem cell transplant may be required.

The survival rates for ALL depend on the age at which it is diagnosed. Children

with ALL have a five-year survival rate of between 65 and 75%, while for adults

it is only 20–35%.

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Chris, a 56-year-old man, recently noticed that he

needed to urinate more frequently, especially during the

night. Also, urination was painful. He visited his doctor

where a rectal examination showed his prostate gland to

be enlarged and smooth. A blood sample was taken for a

PSA test. The results showed the level of PSA in his blood

to be 5.3 ng cm–3.

Questions

(a) What is the likely diagnosis for Chris?

(b) What would be the recommended treatment?

CASE STUDY 17.1

Rebecca is a 55-year-old woman. About four weeks ago

she developed a bad cold and cough. While the cold

cleared up, the cough has remained and has become

more painful. During the last week she was alarmed to

find that she was coughing blood into her handkerchief,

especially first thing in the morning. Rebecca gave up

smoking about two years ago, but was previously a

smoker of 20 cigarettes a day, starting from the age of

23 years. Her husband also smokes. Rebecca visited

her physician who referred her to a consultant. The

consultant saw Rebecca two weeks later and she had a

full examination, including a chest X-ray.

Questions

(a) What clinical findings might the physician be

expecting to see?

(b) What is the risk of Rebecca having lung cancer if

she is a nonsmoker?

CASE STUDY 17.2