Sok, D

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18 Malawi Medical Journal. January 1994. Vol. 10. No 1 SHORT REPORTS Peripheral Lymphocytosis In Tropical Splenomegaly Syndrome D.SOK INTRODUCTION Splenomegaly (a spleen greater than 10 cm) is a com-mon finding in patients in Africa and can be caused by many diseases (See Table). In Malawi, schistosomiasis due to S.mansoni, and the Tropical Splenomegaly Syn-drome (TSS) are believed to be the major causes I. Table: Some common causes of massive splenomegaly in Africa. TROPICAL SPLENOMEGALY SYNDROME HEPATIC CIRRHOSIS HEP ATO-SPLENIC SCHISTOSOMIASIS VISCERAL LEISHMANIASIS CHRONIC GRANULOCYTIC LEUKAEMIA CHRONIC LYMPHOCYTIC LEUKAEMIA MYELOFIBROSIS LYMPHOMA HAEMATOLOGICAL DISEASES, eg THALASSAEMIA TSS results from an abnormal immunological response to malaria in certain genetically predisposed individual2.3• Diagnosis is largely by exclusion of other known causes of splenomegaly. In the majority of patients with TSS a mas-sive spleen, often accompanied with some degree of hepa-tomegaly, is the only dominant clinical feature. . A number of laboratory investigations (high malanal antibody titres and high serum levels ofIgM) are helpful in confirming the diagnosis. Unfortunately these are g~ner­ally unavailable in Malawi. A blood film does not contnbute towards the diagnosis because it can be either positive or negative. However, a full blood count and white blood cell differentiation are often available, and these may show certain abnormalities which clinicians should be aware of. The following case history illustrates this point. Case Report A 50-year old woman presented in. the outpatie~ts de-partment with a three month complamt of full~ess In the abdomen after meals. She had no other complaInts; more specifically she had not experienced any weig~lt loss or feve~. On examination, she was an elderly woman In good condI-tion, moderately pale and not jaundiced. There was no lymphadenopathy. On abdominal examinatio~ a massi~ely enlarged spleen was found (Hackett grade 5. I.e. reachmg beyond the level of the iliac crests); the liver was not palpable . and no ascites could be detected. Laboratory investigations showed:- Haemoglobin 6.B g/d!-, 3 • Total white cell count 52,BOO/m , of WhICh 94% were lymphocytes; red cell morphology normocytic and nor-mochromic; platelet estimation normal. The differential diagnosis included TSS or chronic lymphocytic leukaemia (eLL). There was nothing in the clinical evaluation to suggest eLL, and she was therefore treated for TSS with antimalarial chemoprophylaxis (chloroquine 300 mg base once a week). .. On review 3 months later, she reponed sIgJ1Ificant subjective improvement. On examination the size of bel' spleen had remarkably decreased to Hackett grade 3 Montforl Mission Hospital, PO Box 68, Nchalo, Lower Shire, Malawi. Correspondence lO: Dr Dinanl Sok (umbilical level). The total white cell count had de-creased to 50;300/m3, of which 9B% were lymphocytes. It was explained to her that treatment with antimalarial chemoprophylaxis must continue for life. DISCUSSION It is not common knowledge that TSS can be associated with marked peripheral blood lymphocytosis, and given this laboratory picture many patients will be diagnosed as having chronic lymphocytic leukaemia eLL. The usual haematological finding in TSS is pancytopenia, resulting from hypersplenism. However, in Nigeria it is not un-common to see patients with TSS who have high periph-eral blood lymphocytosis2 , and surveys done in Africa show that as many as 15% of patients have a lymphocy-tosis within a range of 4.5 - 100.0 x 109/1 3 • eLL is the commonest leukaemia in Africa as well as in the industrialised world. Lymphocytosis, splenomegaly and lymphadenopathy are characteristic features, although the latter may be absent. The total blood lymjhocyte count in eLL is often higher than 100.0 x 10 /1, whereas in TSS it is generally lower. Bone marrow aspiration may not allow differentiation of the two conditions, as both may show excessive lymphocytic infiltration. Liver histology can be diagnostic by showing the characteristic infiltration in hepatic sinusoids of TSS, but genemlised lymphocytic infiltration occurs in both conditions. More conclusive techniques to differentiate between the two diseases include testing whether the lymphocytes rosette with mouse red cells and whether the lymphocytes are mainly B cells with weak st';lirling mono-clonal surface immunoglobulin, both characteristic of eLL. In addition to this, determination of serum IgM concentrations could be usefue·3, being characteristically elevated in TSS. None of these sophisticated investiga-tions are readily available to clinicians in Malawi, so in some patients who present with splenomegaly and lym-phocytosis, it may be very difficult to distinguish TSS from eLL. Patients with TSS respond to antimalarial chemoprophylaxis, although some patients with eLL may show a partial and transient response as we1l4• If in doubt about the diagnosis, I suggest that such patients be treated with antimalarial chemoprophylaxis . In cases of TSS, this will greatly reduce morbidity and mortality and will eventually lead to complete regression of splenomegaly, which confirms the diagnosis. The patient feels better after a few weeks of treatment, and the spleen decreases in size and becomes impalpable in 1 or 2 years. The lymphocytosis, however, may persis{ Treatment must be continued for life. REFERENCES I. Reeve, P.A., Wirillla lJ· Common Medical Problems in Malawi. 1990: 47-48. ~. Manson-BaliI' PEC. Bell DR. Manson's Tropical Diseases. London: Bailliere Tilldall, 1987: 22-23, 972-973, 977-978. 3. Parry EHO. Principles of Medicine in Africa. Oxford: Oxford Universily Press, 1984: 729, 889-891. 4. Paparello SF, Hoffman SL. Hyperreactive malarial splenomegaly: Pan I. Postgraduale Doctor (Africa) 1993; 15: 22 - 25. Reproduced  by Sabinet Gateway under licence granted by the Publisher ( dated 2012)

Peripheral lymphocytosis in tropical splenomegaly syndrome

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Peripheral lymphocytosis in tropical splenomegaly syndrome

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