Massive splenomegaly in Northern Zambia. I. Analysis of 344 cases

[Splenic lymphoma, diagnosis and treatment]

Some common clinical situations, such as splenomegaly or lymphocytosis, or less common, such as autoimmune hemolytic anemia, cold agglutinin disease, or cryoglobulinemia can lead to the diagnosis of splenic lymphoma. Splenic lymphoma is rare, mainly of non-hodgkinian origin, encompassing very different hematological entities in their clinical and biological presentation from an aggressive form such as hepato-splenic lymphoma to indolent B-cell lymphoma not requiring treatment such as marginal zone lymphoma, the most frequent form of splenic lymphoma. These entities can be challenging to diagnose and differentiate. This review presents different clinical and biological manifestations suspicious of splenic lymphoma and proposes a diagnosis work-up. We extended the strict definition of splenic lymphoma (lymphoma exclusively involving the spleen) to lymphoma thant can be revealed by a splenomegaly and we discuss the differential diagnosis of splenomegaly.

Splenomegaly in Children and Adolescents

In contrast to other lymphoid tissues making up the immune system, the spleen as its biggest organ is directly linked into the blood circulation. Beside its main task to filter out microorganism, proteins, and overaged or pathologically altered blood cells, also humoral and cellular immune responses are initiated in this organ. The spleen is not palpable during a physical examination in most but not all healthy patients. A correct diagnosis of splenomegaly in children and adolescents must take into account age-dependent size reference values. Ultrasound examination is nowadays used to measure the spleen size and to judge on reasons for morphological alterations in associated with an increase in organ size. An enormous amount of possible causes has to be put in consideration if splenomegaly is diagnosed. Among these are infectious agents, hematologic disorders, infiltrative diseases, hyperplasia of the white pulp, congestion, and changes in the composition and structure of the white pulp by immunologically mediated diseases. This review attempts to discuss a comprehensive list of differential diagnoses to be considered clinically in children and young adolescents.

The hyper-reactive malarial splenomegaly: a systematic review of the literature

BACKGROUND

The hyper-reactive malarial splenomegaly syndrome (HMS) is a leading cause of massive splenomegaly in malaria-endemic countries. HMS is caused by a chronic antigenic stimulation derived from the malaria parasite. Classic Fakunle's major criteria for case definition are: persistent gross splenomegaly, elevated anti-malarial antibodies, IgM titre >2 SD above the local mean value and favourable response to long-term malaria prophylaxis. The syndrome is fatal if left untreated. The aim of this study is to systematically review the literature about HMS, particularly focussing on case definition, epidemiology and management.

METHODS

The search strategy was based on the following database sources: Pubmed, EmBase, Scopus. Search was done in March, 2014 and limited to English, Spanish, Italian, French, and Portuguese.

RESULTS

Papers detected were 149, of which 89 were included. Splenomegaly was variably defined and the criterion of increased IgM was not always respected. The highest prevalence was reported in Papua New Guinea (up to 80%). In different African countries, 31 to 76% of all splenomegalies were caused by HMS. Fatality rate reached 36% in three years. The most frequent anti-malarial treatments administered were weekly chloroquine or daily proguanil from a minimum of one month to lifelong. In non-endemic countries, a few authors opted for a single, short anti-malarial treatment. All treated patients with no further exposure improved. Cases not completely fulfilling Fakunle's criteria and therefore untreated, subsequently evolved into HMS. It seems thus appropriate to treat incomplete or 'early' HMS, too.

CONCLUSIONS

For patients not re-exposed to endemic areas, a short course of treatment is sufficient, showing that eradicating the infection is sufficient to cure HMS. Longer (probably lifelong) courses, or intermittent treatments, are required for those who remain exposed. Splenectomy, associated with high mortality, should be strictly limited to cases not responding to medical treatment.

Massive splenomegaly in rural Malawi: new wine, old wineskins and the importance of collaboration

During a voluntary placement in rural Malawi, we assessed a 21-year-old man who presented with dyspnoea and lethargy secondary to a chronic refractory anaemia associated with massive splenomegaly. He was initially treated at the rural hospital for a presumptive diagnosis of hyper-reactive malarial syndrome (HMS) with long-term malarial prophylaxis. There was inadequate provision of blood products and the availability of suitable donors was limited by the high local prevalence of blood-borne viruses. He was transferred to the district hospital for further investigations after transfusion of three units of blood. Unfortunately, he self-discharged without receiving appropriate investigations and medical treatment. Subsequently, his family sought help from the local traditional healer who performed scarification to attempt to treat him. Further efforts to emphasise the importance of hospital-based care proved unsuccessful, and sadly this man died at his family home 3 months after his initial presentation.

Splenomegaly: investigation, diagnosis and management

Splenomegaly is a feature of a broad range of diseases, and presents to clinicians in many fields. This review examines the aetiology of splenomegaly in the developed world, and describes a logical approach to the patient with splenomegaly. In some patients, extensive radiological and laboratory investigations will fail to yield a diagnosis: these cases of "isolated" splenomegaly are not uncommon and can be particularly challenging to manage. The risks of serious underlying disease must be balanced against the risks of invasive investigations such as splenic biopsy and diagnostic splenectomy. We discuss the options in isolated splenomegaly and their evidence base, and incorporate them into a management strategy to aid the clinician in cases of diagnostic difficulty.

Hyperreactive malarial splenomegaly in expatriates

Hyperreactive malarial splenomegaly, one of the major causes of splenomegaly in tropics, has been often reported in expatriates of non-tropical settings. Essential features are recurrent malarial infection, overproduction of IgM and hyperplasia of lymphoreticular system. The practice of diagnosing the condition by exclusion of obvious causes of splenomegaly in the tropics has been abandoned. There are specific criteria for the diagnosis. Huge splenomegaly >10 cm below costal margin, serum IgM more than 2 x standard deviation (2SD) above the local mean, high titre of malarial antibodies and response to antimalarial drugs are the cornerstones of the diagnosis. Splenic lymphoma with villous lymphocytes coexists with this condition and it should always be considered in the differential diagnosis of unresponsive or poorly responsive cases of hyperreactive malarial splenomegaly. Condition with fever and acute haemolysis in HMS has been termed as Fulminant tropical splenomegaly syndrome. Treatment of the condition depends on antimalarial (chloroquine/ proguanil/ pyrimethamine) chemoprophylaxis for 1 year or more.

Investigation of familial segregation of hyperreactive malarial splenomegaly in Kumasi, Ghana

Hyperreactive malarial splenomegaly (HMS), a common cause of massive splenomegaly in malaria-endemic regions, is defined as persistent splenomegaly without demonstrable underlying disease. Previous studies have found HMS more frequently in certain tribes in Papua New Guinea, Uganda and Nigeria, with strong familial associations in Uganda and Papua New Guinea. This case-control study aimed to determine the extent of familial association of splenomegaly and the pattern of segregation of the condition in families in Ghana. It involved 22 HMS cases with 99 relatives, and 15 population controls of similar socio-economic background with 51 relatives. The pedigree of each family was recorded. Clinical and laboratory data were collected on all participants, including the presence and degree of splenomegaly. Relatives with splenomegaly were identified for 27% of HMS cases and for 6.7% of population controls (P=0.04). There were significant differences in the IgM levels, which were higher (P=0.005), and the haemoglobin levels, which were lower (P=0.009), in cases compared with controls. In Ghana, relatives of HMS cases are more likely to have splenomegaly than population controls, but with no obvious pattern of Mendelian segregation. HMS aetiology in Ghana is likely to be complex, involving multiple genetic and environmental factors.

Causes of massive tropical splenomegaly in Ghana

BACKGROUND

The causes and diagnosis of massive tropical splenomegaly are not well studied, especially with modern investigative methods. We aimed to identify features that would help local clinicians differentiate between the underlying conditions.

METHODS

We collected prospective clinical and laboratory data on 221 Ghanaian patients with spleen size of at least 10 cm. We identified conditions associated with massive splenomegaly with molecular and immunological investigations as well as routine tests. Patients were assigned to diagnostic categories on the basis of these test results and predetermined criteria.

FINDINGS

Hyper-reactive malarial splenomegaly (HMS; 91 patients [41%]) and B-lymphoproliferative disorders (48 [22%]) were the most common disorders associated with massive splenomegaly. Of the remaining patients, 32 (14%) had haematological disorders, and in 50 (23%) we could not identify the cause of splenomegaly. Male sex predominated in all diagnostic groups except HMS and tropical splenic lymphoma. Age less than 40 years and absolute lymphocyte count (less than 10 x 10(9)/L) were the only useful and widely available discriminators for distinguishing patients with HMS from those with lymphoproliferative disorders.

INTERPRETATION

B-lymphoproliferative disorders are a previously unrecognised cause of massive tropical splenomegaly. This finding has major implications for management of massive splenomegaly. Diagnosis of the less common causes of this disorder is usually straightforward, but differentiating between B-lympho proliferative disorders and HMS can be difficult. HMS is associated with younger age, a higher proportion of women, and lower absolute lymphocyte counts than lympho proliferative disorders.

Circulating villous lymphocytes--a link between hyperreactive malarial splenomegaly and splenic lymphoma

Significant numbers of villous lymphocytes were noted in the blood of patients with a clinical diagnosis of hyperreactive malarial splenomegaly (HMS) in Ghana. Demographic and haematological data were recorded from 22 patients with massive splenomegaly. Additional investigations included lymphocyte immunophenotyping, protein electrophoresis and immunoglobulin gene rearrangements. Although all patients had over 30% villous lymphocytes and no leucocytosis, 7 had no evidence of a monoclonal disorder. Immunophenotyping and the presence of monoclonal lymphocytes identified 3 further patients with B-cell splenic lymphoma with villous lymphocytes (B-SLVL). HMS and SLVL co-existed in the same, predominantly female, patient population and were indistinguishable except by molecular analysis of lymphocytes. The discovery of the uncommon villous lymphocytes in both non-malignant and malignant disorders in the same geographical area suggested that HMS and SLVL are pathophysiologically related. In Caucasians with SLVL the malignant cells arise from B-cells that have undergone antigen selection. We postulate that the excessive proliferation of polyclonal B-lymphocytes, driven by frequent exposure to malaria, predisposes to the emergence of a malignant lymphoma, B-SLVL, in tropical West Africa.

Hyperreactive malarial splenomegaly in pregnancy

Hyperreactive malarial splenomegaly (HMS) is common in many tropical areas and particularly affects women of reproductive age. It is associated with anaemia which can be debilitating in patients already compromised by anaemia due to poor nutrition and pregnancy. The course of the disorder in pregnancy is commonly punctuated by episodes of haemolytic anaemia which can be life-threatening to the mother and cause increased fetal morbidity and loss. Management of the chronic state consists of lifelong anti-malarial therapy supplemented by haematinics. Blood transfusions may be required to treat episodes of severe haemolysis.

The sickle-cell trait modifies the intensity and specificity of the immune response against P. falciparum malaria and leads to acquired protective immunity

It is proposed that the in vivo mechanism of protection against falciparum malaria in individuals of the Hb AS genotype is not due solely to the adverse influence of Hb AS erythrocytes on the intraerythrocytic growth and development of P. falciparum. Instead, the simple physiological effect of Hb S on parasite growth appears to trigger an in vivo process of enhancement of the intensity and/or specificity of the host immune response, leading to acquired protective immunity, in a process simulating vaccination. Testing the hypothesis may lead to the identification of plasmodial antigens that induce protective responses in the human host and distinguish them from non-protective, immunosuppressive or decoy antigens that promote parasite survival. This may ultimately help in the selection of candidate antigens for a malaria blood-stage vaccine.

Chronic splenomegaly in Nairobi, Kenya. I. Epidemiology, malarial antibody and immunoglobulin levels

Chronic splenomegaly in 131 Kenyan patients was investigated at Kenyatta National Hospital, Nairobi. Patients were allocated to diagnostic groups on the basis of clinical, haematological, parasitological, histological, radiological and endoscopic data. The major diagnostic groups were hyper-reactive malarial splenomegaly, our preferred name for tropical splenomegaly syndrome, (31%), hepatosplenic schistosomiasis (18%), visceral leishmaniasis (5%) and "indeterminate splenomegaly", where no diagnosis could be reached (12%). Another 20% of patients were suffering from various non-schistosomal forms of portal hypertension. A number of specific and rarer causes accounted for the rest of the cases. The tribal and geographical distribution of patients with chronic splenomegaly was compared with the pattern of general medical admissions. Splenomegaly was more frequent than expected in Kamba and Luo patients. Hyper-reactive malarial splenomegaly and hepatosplenic schistosomiasis were common in both groups, whereas visceral leishmaniasis was almost restricted to the Kamba and indeterminate splenomegaly was especially prevalent in the Luo. Malarial antibody and immunoglobulin levels differed significantly between the various diagnostic categories of patients and controls. Malarial serology can be diagnostically useful for chronic splenomegaly, provided results are interpreted in their geographical context.

Massive splenomegaly in Northern Zambia. II. Schistosomal splenomegaly and elevated IgG

Twenty-three patients from Northern Zambia with massive splenomegaly due to chronic schistosomiasis were studied. The mean serum IgG levels were found to be extremely high compared with local blood donors and local patients with Tropical Splenomegaly Syndrome (TSS). Mean serum IgG levels also appear to be higher in Zambians with schistosomal splenomegaly than in those reported in patients from most other areas. Mean IgM levels of patients with schistosomal splenomegaly were higher than those of local blood donors, but not as high as in the TSS. IgG and IgM estimations are sometimes of value in the differential diagnosis of splenomegaly in the tropics.