10 research outputs found
Pulmonary Langerhans Cell Histiocytosis in pre-existing chronic myelomonocytic leukaemia: a rare association
Supplementary Material for: A Prospective Study to Evaluate a Diagnostic Algorithm for the Use of Fluid Lymphocyte Subset Analysis in Undiagnosed Unilateral Pleural Effusions
<p><b><i>Background:</i></b> Haematological malignancy is an important
cause of pleural effusion. Pleural effusions secondary to haematological
malignancy are usually lymphocyte predominant. However, several other
conditions such as carcinoma, tuberculosis, and chronic heart failure
also cause lymphocytic effusions. Lymphocyte subset (LS) analysis may be
a useful test to identify haematological malignancy in patients with
lymphocytic effusions. However, research into their utility in pleural
effusion diagnostic algorithms has not yet been published. <b><i>Objectives:</i></b>
We aimed to determine the clinical utility of pleural fluid LS analysis
and whether it can be applied to a diagnostic algorithm to identify
effusions secondary to haematological malignancy. The secondary aim was
to evaluate the diagnostic value of pleural fluid differential cell
count. <b><i>Methods:</i></b> Consecutive consenting patients presenting
to our pleural service between 2008 and 2013 underwent thoracentesis
and differential cell count analysis. We proposed an algorithm which
selected patients with lymphocytic effusions (>50%) to have further
fluid sent for LS analysis. Two independent consultants agreed on the
cause of the original effusion after a 12-month follow-up period. <b><i>Results:</i></b>
A total of 60 patients had samples sent for LS analysis. LS analysis
had an 80% sensitivity (8/10) and a 100% specificity for the diagnosis
of haematological malignancy. The positive and negative predictive
values were 100 and 96.1%, respectively. Overall 344 differential cell
counts were analysed; 16% of pleural effusions with a malignant
aetiology were neutrophilic or eosinophilic at presentation. A higher
neutrophil and eosinophil count was associated with benign diagnoses,
whereas a higher lymphocyte count was associated with malignant
diagnoses. <b><i>Conclusions:</i></b> LS analysis may identify
haematological malignancy in a specific cohort of patients with
undiagnosed pleural effusions. A pleural fluid differential cell count
provides useful additional information to streamline patient pathway
decisions.</p