A 6-month-old boy from Guinea presented with a 4-month history of a left shoulder nodule at the site of a previous vaccination of unknown type. The child also had recurrent fevers and upper respiratory tract symptoms. On examination, the patient had a 3.5 × 2-cm, rubbery, freely moveable subcutaneous nodule on the left shoulder, which extended into a 6-mm, round, red papule (Figure 1). A 1-cm rubbery subcutaneous nodule was present on the right back. He also had lymphadenopathy in the posterior auricular, cervical, inguinal, and axillary regions. The liver edge was palpable 1 cm below the costal margin. Biopsy specimens from the left shoulder papule (Figure 2 and Figure 3) and left axillary lymph node were obtained. A chest radiogram showed no abnormalities. The child's alkaline phosphatase level was 302 U/L (range, 33-96 U/L) and the aspartate-aminotransferase level, 47 U/L (range, 12-38 U/L) (to convert both these analytes to microkatals per liter, multiply by 0.0167). Test results for hepatitis B surface antigen, hepatitis B core antigen, and anti–hepatitis B core antigen were positive, and the hepatitis B viral load was greater than 250 000 copies.