PURPOSE: A pleural effusion may be the initial manifestation of malignancy. We sought to determine the etiology of the malignancy and clinical course of patients with this presentation.
METHODS: Adult patients presenting from January 2001 to December 2006 at Kings County Hospital with a malignant pleural effusion (MPE) as first manifestation of cancer were identified from discharge diagnoses. Clinical data and outcome variables were extracted from the medical records. Data are presented as mean ± SD or median and 95 CI. Comparisons between groups were done using the Student t-Test for continuous variables. Categorical variables were compared using the Pearson chi-square test. A p value <0.05 was considered statistically significant.
RESULTS: Thirty-two patients (20 women and 12 men) were identified. Mean age at presentation was 62 ± 13 years. They included more women (63%) than men (37%). Adenocarcinoma was the most encountered pathological diagnosis (84%), which had 94% sensitivity, 28% specificity and 80% negative predictive value for diagnosing lung cancer as the primary site. Seventeen patients had adenocarcinoma and 1 had squamous cell carcinoma of lung, 4 had adenocarcinoma with unknown primary, 2 had adenocarcinoma of breast, 2 had T cell lymphoma and the remainder from other origins. Three patients required MICU admission. Eight patients died after diagnosis, before being discharged, with a mean survival of 49±41 days. Mortality was associated with a higher WBC and absolute neutrophil count of pleural fluid. An absolute neutrophil count above 320 (/cu mm) had 74% sensitivity and 79 % specificity in predicting hospital mortality and poor prognosis. Mortality correlated with WBC count (r2=0.74; p<0.05), fluid LDH (r2=0.73; p<0.05) and inversely with fluid glucose level (r2=0.68; p<0.05).
CONCLUSION: Adenocarcinoma of the lung was the most common cause of MPE as initial manifestation (53%). Early hospital mortality and a worse prognosis were associated with a higher pleural fluid WBC and absolute neutrophil count.
CLINICAL IMPLICATIONS: Adenocarcinoma is the most likely diagnosis in MPE as first manifestation. A high absolute neutrophil count can predict early hospital mortality.
DISCLOSURE: Shahram Khorrami, No Financial Disclosure Information; No Product/Research Disclosure Information