Clinical Features, Laboratory Investigations, Prognosis And Treatment In Chronic Lymphatic Leukemia
Enlarged Spleen In Leukemia
This is the commonest type of leukemia occurring in adults in the West, but in developing countries, especially India, this is much less common. In the Mongoloid and Chinese races, also the incidence is very low. Chronic lymphatic leukemia is a neoplasm arising from a clone of immunocytes, occurring usually above the age of 45 years, characterized by the presence of excessive number of lymphocytes in the bone marrow and peripheral blood and organomegaly due to infiltration by lymphocytes.
Most of the caes are B-lymphocyte type, though rarely, T-lymphocytes may be involved. These cells proliferate. The lymph nodes are enlarged and histologically resemble diffuse well-differentiated lymphoma. Liver, spleen and bone marrow show varying degrees of lymphocytic infiltration. Progressive replacement of the normal bone marrow leads to compensatory hyperplasia of the yellow marrow, but finally, the bone marrow fails. Lymphocytes may infiltrate other organs like the skin. At times, monoclonal paraproteins of the Kappa or Lambda type are produced hy the tumour cells even without antigenic stimulation. Normal immune mechanisms of the host are impaired since the abnormal immunocytes are functionally incompetent. Other autoimmune disorders like hemolytic anemia, rheumatoid disease, and Guillain-Barre syndrome may occur in association with chronic lymphatic leukemia.
Lymphadenopathy In Leukemia
Clinical features And Lab Findings
Males are affected twice as frequently as females. The onset is insidious with tiredness and vague ill health and on many occasions the disease is revealed by routine examination in asymptomatic subjects. Clinically, two forms of the disease can be identified- benign and aggressive forms. In about 80% of cases, the disease presents with painless lymphadenopathy, the nodes are moderate to large in size, rubbery in consistency, discrete and are most prominent in the neck and axillae. Enlargement of the lacrimal and salivary glands is known as Mikulicz’s syndrome. Spleen is moderately enlarged (5-10 cm) in 75% of cases and in 10% splenomegaly may be the only sign in the absence of lymphadenopathy. Cutaneous involvement presents as nodules, or a diffuse infiltration producing a picture of erythroderma (home rouge). The immune deficiency contributes to recurrent infections of the respiratory and urinary tracts.
Diagnostic finding in peripheral blood is the marked leukocytosis (50- 200 X 109/liters or 50,000- 200,000/cmm) consisting almost totally of small mature lymphocytes. The cells are uniform in type and blasts form only less than 3%. They may increase in the later stages. The total leukocyte count does not bear a direct relationship to the tumour load. Many lymphocytes are ruptured and these are termed smudge cells or basket cells. The normal bone marrow is replaced by lymphocytes which form 25-95% of the total cells. The total body potassium is increased corresponding to the tumour load.
The differential diagnosis includes other causes of lymphoid leukemoid reaction and lymphosarcoma with extension to bone marrow and blood. When lymphosarcoma produces a leukemoid picture, the cells are larger and their nuclei show lobulation.
A clinical staging has been accepted since it correlates with the response to treatment and survival.
Staging of chronic lymphatic leukemia
Lymphocytes 15 X 109/liter or more in peripheral blood and 40% or more in the bone marrow. No enlargement of lymph nodes, spleen or liver. Hemoglobin is above 11 gm/dl and platelet cout is over 100 X 109/liter.
Features as in stage 0, but with enlarged lymph nodes
As in stage 0, but with enlarged spleen, liver or both. Lymph nodes may or may not be enlarged.
As in Stage II, but with hemoglobin less than 11 g/dl.
As in Stage III, but with platelet count below 100 X 109/liter.
Course and prognosis
In the Caucasian races, the disease follows a slow and progressive course, remaining asymptomatic for several years, and ultimately ending fatally because of infection, bone marrow failure, cachexia, or iatrogenic complications. In general, patients with stages I, II and III disease survive for 150, 101 and 71 months respectively. Stage III and IV d not show any significant difference in survival. Though acute lymphoblastic or even acute myeloid leukemia may occur terminally in a few cases, unlike chronic myeloid leukemia terminal blast crisis is very rare.
The aggressive form is more common is Indians. This type follows a more rapidly progressive course, punctuated by episodes of infection. Death occurs within 2-3 years in the majority of cases. Since the total leukocyte count does not bear a direct relation to the tumour load, this is not useful in prognosis. High leukocyte count by itself is not an indication for starting therapy. Treatment helps to allay symptoms and relieve suffering and hence treatment is indicated in all symptomatic cases though it is not clear whether it prolongs life.
Treatment Of Leukemia Patients
Although it is customary in the west to withhold treatment till the disease reaches stages III or IV, in Indian subjects for instance, treatment may have to be started earlier, depending on the progress and extent of the disease. Specific treatment is with chlorambucil (Leukeran B.W) 0.05 to ).1 mg/Kg/body weight per day in continuous dosage till the total leukocyte count becomes normal and the morphological lesions disappear. An alternate dosage schedule is 0.4 mg/Kg/body weight twice a week intermittently. Corticosteroids enhance the effect of alkylating agents. Optimal improvement occurs in 1-2 years, though the neoplasm is not eradicated. Combination chemotherapy has been beneficial in resistant cases. The usual combination is cyclophosphamide, doxorubicin, vincristine and prednislone.
Splenic irradiation with a total dose of 300- 1000 rads in divided doses brings about remission in 6-12 months. Total body irradiation with a dose of 150 rads (15 rads twice a week for 5 weeks) of 32P has been very successful in bringing about clinical remission.
Leucapheresis has been found to be beneficial in removing the leukemic cells and thereby reducing the tumour load in intractable cases.
© 2014 Funom Theophilus Makama