For each patient with lymphadenopathy, select the most likely diagnosis.
1. A previously healthy 30-year-old man has had fever, night sweats, pruritus, and an enlarging lump above his left clavicle for 3 weeks. Examination shows a 3-cm, nontender, rubbery, supraclavicular lymph node. An x-ray of the chest shows mediastinal lymphadenopathy.
2. A 41-year-old woman comes to the physician for a follow-up examination. She has taken aspirin for chronic headaches and phenytoin for a seizure disorder for 2 years. Examination shows mild epigastric tenderness and bilateral, 3-cm, nontender axillary lymph nodes. A lymph node biopsy shows hyperplasia. [/SIZE]