A 63-year-old man comes to the physician because of intermittent fevers and a 5-month history of a weight loss of 5 kg (11 lb). Currently, temperature is 38.5oC (101.3oF). Physical examination shows generalized, nontender lymphadenopathy. The spleen tip can be palpated. Laboratory studies show a hemoglobin of 10.2 g/dL, a platelet count of 145,000/mm3, and a WBC count of 25,200/mm3 with 10% segmented neutrophils, 1% bands, 86% lymphocytes, and 3% monocytes. Examination of a cervical lymph node biopsy specimen shows a nodular pattern of small lymphoid cells (CD5+, CD10–). Cytogenetic studies show the presence of a t(11;14) translocation. Which of the following is the most likely diagnosis?

A 69-year-old man comes to the physician because of a 4-month history of weakness, fatigue, “oozing” epistaxis, and weight loss, as well as a recent history of blurred vision, headaches, and dizziness. He also reports his hands have become markedly sensitive to cold. Physical examination shows hepatosplenomegaly and lymphadenopathy. Laboratory studies show hyperproteinemia with a total serum protein of 14.7 g/dL and an albumin concentration of 3.3 g/dL. Examination of a bone marrow biopsy specimen shows extensive infiltration with lymphoid cells and plasma cells filled with immunoglobulin containing droplets. Which of the following additional findings is most likely in this patient?

A 3½-year-old boy is brought to the physician because of a 5-day history of listlessness. His mother states that the boy experiences pain when she picks him up, and that he resists being touched on the arms or legs. One day ago, several large ecchymoses were noted over the right thigh. Complete blood count shows a hemoglobin of 9.7 g/dL, a mean corpuscular volume of 96 mm3, a platelet count of 39,000/mm3, and a WBC count of 14,100/mm3. Examination of a peripheral blood smear discloses blasts that lack peroxidase positive granules but contain PAS-positive aggregates and that stain positively for TdT. Flow cytometry shows the blasts are CD19+, CD3–, and surface Ig– (sIg–). Which of the following is the most likely diagnosis?

A 27-year-old man comes to the physician because of lumps over the neck that have been getting larger during the past 4 months. On physical examination, a group of enlarged, non-tender, right cervical lymph nodes are palpated. Examination of a node biopsy specimen shows scattered Reed-Sternberg cells, as well as macrophages, lymphocytes, neutrophils, eosinophils, and a few plasma cells. Which of the following factors synthesized by Reed-Sternberg cells accounts for the presence of eosinophils within the involved lymph nodes?

A patient with a history of glucose-6-phosphate dehydrogenase (G6PD) deficiency is undergoing evaluation because of a urinary tract infection. Free radicals generated by the responding neutrophils create an oxidant stress causing hemolysis. Serum levels of which of the following are most likely to decrease when intravascular hemolysis begins in this patient?