Use of cholesterol to differentiate tuberculous from malignant pleural effusions

Abstract EN

One of the main problems facing pulmonologists and internists is differentiating tuberculous effusions from malignant effusions.

To help in this decision making we prospectively evaluated the pleural (P) cholesterol and its serum (S) ratio in 39.63 patients suspected either of malignancy or tuberculosis.

Method : In 39 patients whose clinical presentation suggested either malignant or tuberculous effusion chest X-ray was taken to determine the size and the site of the effusion.

In a fasting state, fluid was drawn for cytology, A.F.B.

smear and culture, LDH, protein, glucose, cholesterol, and triglyceride.

Simultaneously blood was sent for evaluation of the same biochemistry parameters.

In all cases the definitive diagnosis was made by pleural biopsy.

Results : Of 39 patients 21 had tuberculosis and 18 had malignancy.

Using SPSS-Pc+program it chose pleural to serum cholesterol ratio as a variable with significant difference.

The mean ratio for tuberculous patients was 0.52 and the patients with malignancy had ratio of 0.44 with P < 0.01.

Plugging P / S cholesterol ratio into two formulas (1) T.B = P.S cholesterol × 60.38-16.45 : (2) malignancy = P / S cholesterol × 50.64-11.91.

Our diagnosis is most likely the one with higher value (P < 0.007).

Conclusion : In difficult cases where diagnosis of either a malignant pleural effusion or tuberculosis is either a malignant pleural effusion or tuberculosis is difficult use of cholesterol level or its ratio can play a pivoting role.