Persistent lymphocytopenia as a diagnostic feature of bronchogenic carcinoma.

Patients with abnormalities due to bronchogenic carcinoma, noted on chest films, have decreased peripheral blood lymphocytes and increased total white cells compared to patients with benign lesions. Precision studies of 40 patients revealed that a low percentage of lymphocytes averaged over a three-week period distinguished bronchogenic carcinoma patients from patients with benign lesions with 95 percent overall accuracy. Lesions as small as 1.0 cm were correctly predicted to be malignant. Mean 8 AM plasma cortisol levels were elevated in patients with bronchogenic carcinoma and there was a negative correlation of 8 AM plasma cortisol levels with precentage of lymphocytes. Increased levels of endogenous cortisol may account for lymphocytopenia in bronchogenic carcinoma patients.