May Be Caused by

 Common

AIDS

Histoplasmosis

Idiopathic lymphadenitis

Infectious lymphadenitis

Lymphoma

Lymphosarcoma

Metastasis

Plague

Sarcoidosis

Small cell lung carcinoma

Tuberculosis

Tularemia

Undifferentiated lung carcinoma

 Uncommon

Castleman disease

Drug reaction

Erythema nodosum

Hydantoin