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.