lymphadenopathy
Viral
HIV, EBV, CMV, HSV, VZV, hepatitis, measles, rubella
Bacterial
Generalized (brucellosis, leptospirosis, TB, atypical mycobacteria, syphilis)
Localized (streptococci, staphylococci, cat-scratch disease, tularemia)
Fungal/parasitic
Histo, coccidio, paracoccidioidomycosis, toxoplasmosis
Immunologic
Collagen vascular disease, drugs (eg, phenytoin), serum sickness, histiocytosis X, Castleman’s and Kawasaki disease
Neoplasm
Lymphoma, leukemia, amyloidosis, metastatic carcinoma
Other
Sarcoidosis; lipid storage diseases
Factors that favor biopsy
Pt >40 y, >2 cm, location (supraclavicular always abnl), duration >1 mo
Consistency (hard vs. rubbery vs. soft) & tenderness are not reliable
Exicisional biopsy preferred over fine needle aspiration (FNA)