A 30-year-old man with a 2-week history of cervical lymphade

A 30-year-old man presents to the emergency department with a 2-week history of cervical lymphadenopathy, drenching night sweats, and unintentional weight loss of 15 lb. A CT scan shows diffuse, bulky lymphadenopathy in the neck, mediastinum, retroperitoneum, and iliac lymph nodes. Laboratory results reveal a blood urea nitrogen level of 56 mg/dL, serum creatinine level of 2.5 mg/dL, calcium level of 13 mg/dL, and a lactate dehydrogenase level 4 times the upper limit of normal. His complete blood count is normal except for a leukocyte count of 24.6 ×103/µL with 70% lymphocytes, some of which are atypical in appearance. He is originally from Jamaica and has no significant past medical history. He has had multiple female sexual partners but has never used intravenous drugs. Which virus is the most likely cause of this patient’s illness?

Cytomegalovirus
Dengue virus
Epstein-Barr virus
HIV
Human T-lymphotrophic virus type 1 (HTLV-1)

HTLV-1. This patient has adult T-cell lymphoma/ leukemia (ATLL), a T-cell neoplasm associated with infection by HTLV-1, a retrovirus endemic to Japan, the Caribbean basin (including Jamaica), Africa, and the southeastern United States.5 The virus is spread via sexual contact, breast feeding, and blood transfusion. Patients with the acute form of ATLL present with rapidly developing B symptoms (eg, night sweats, weight loss), with diffuse lymphadenopathy, lymphocytosis, and hypercalcemia often associated with acute renal insufficiency. The disease responds poorly to therapy and is almost universally fatal. HIV, Epstein-Barr virus, and cytomegalovirus can all present with diffuse lymphadenopathy, but lymphocytosis is less common and hypercalcemia is rarely seen. Dengue fever occurs in the Caribbean but causes bone pain, not diffuse lymphadenopathy.