4.  A young woman presents with fever, enlarged cervical lymph nodes, and leukopenia on the cell blood count. A lymph node biopsy reveals extensive areas of necrosis with nuclear debris surrounded by lymphocytes, histiocytes, and large numbers of plasmacytoid monocytes. Neutrophils are not present in the necrotic areas. Which of the following is the most likely diagnosis?

  5.  This photomicrograph shows the most characteristic set of histologic changes that develop in regional lymph nodes 2 to 3 weeks after a cat bite or scratch. Which of the following is it?

  6.  The pattern of follicular hyperplasia seen in this lymph node is most characteristic of:

  7.  A biopsy of a large mediastinal mass reveals the microscopic features detailed in these low-power and high-power photomicrographs (A and B), consisting of atretic lymphoid follicles, with a central hyalinized vessel surrounded by concentric layers of lymphocytes. Which of the following is true about this condition?

  8.  A lymph node biopsy from a patient with fever, cervical lymphadenopathy, and splenomegaly reveals the histopathologic changes depicted in these photomicrographs, which consist of marked interfollicular expansion by a mixed cellular infiltrate with numerous immunoblasts, small lymphocytes, and few plasma cells. The follicular architecture is partially preserved. Which of the following is the most likely diagnosis?

  9.  A characteristic feature of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) is shown in this picture. Which feature is it?

10.  A young patient presents with localized cervical lymph node enlargement and fever. One of the lymph nodes is biopsied and reveals the changes shown in this picture. Which of the following features is frequently associated with the lymph node pathology in this condition?

11.  A 25-year-old man presents with cervical node enlargement. A biopsy of an affected lymph node shows effacement of lymph node architecture by a nodular growth, a thin rim of compressed normal node, and a predominantly small lymphocytic population with admixed histiocytes and scattered large cells like those seen in this picture. The latter are immunoreactive for CD45, CD20, CD79a, Bcl-6, and PAX-5 and negative for CD15. Which of the following is the Hodgkin lymphoma (HL) variant in this case?

12.  A biopsy of an enlarged cervical lymph node reveals a nodular growth pattern that effaces the nodal architecture, sparing an attenuated rim of residual lymphoid tissue. Within a cellular background rich in small lymphocytes, classic RS cells are identified. The latter express CD15, but not CD45. Which of the following is the HL variant in this case?

13.  A lymph node biopsy in a case of suspected lymphoma reveals a nodular pattern of growth with broad bands of collagen, as shown in this low-power photomicrograph (A). A mercuric chloride–fixed section demonstrates a mixed lymphohistiocytic, plasmacellular, and eosinophilic infiltrate, along with the cells shown in this high-power photomicrograph (B). These cells are CD15 and CD30 positive and CD45 negative. Which of the following is the HL variant in this case?

14.  A lymph node biopsy reveals the cell population shown in this picture, including many classic RS cells. In this case, a diagnosis of mixed cellularity Hodgkin lymphoma (MCHL) is justified if:

15.  Which of the following is true about lymphocyte-depleted Hodgkin lymphoma (LDHL)?

16.  Which of the following immunophenotypes is characteristic of classical RS cells?

17.  A lymph node biopsy from a 60-year-old man with peripheral lymphocytosis and generalized lymphadenopathy reveals complete effacement of the nodal architecture, as shown in this picture. This is replaced by diffuse sheets of small lymphocytes with round nuclei and scanty cytoplasm. Mitotic figures are rare. Which of the following immunocytochemical, cytogenetic, or molecular findings would be consistent with this morphology?

18.  A 65-year-old woman is found to have enlargement of multiple lymph nodes. Involvement of the spleen and liver is also documented. A lymph node biopsy reveals complete architectural effacement by a mixed population of lymphocytes, plasmacytoid lymphocytes, and plasma cells. Some of the plasmacytoid lymphocytes have nuclear inclusions highlighted by PAS staining, as shown in this picture. Which of the following features is associated with most cases of this lymphoproliferative disorder?

19.  A 70-year-old man suffers from a lymphoma involving lymph nodes, bone marrow, spleen, and brain. Histologically, the lymph nodes display a vaguely nodular architecture, with striking expansion of the mantle zone around small residual follicles, as shown in this low-power photomicrograph (A). This high-power photomicrograph (B) demonstrates the cytologic features of the abnormal lymphocytic population. Which of the following genotypic abnormalities characterizes this type of lymphoma?

20.  This low-power photomicrograph shows a lymphoma composed of CD10-positive and CD5-negative lymphocytes with high levels of cytoplasmic IgG. Which of the following cytogenetic abnormalities is most likely to be present?

21.  Which of the following methods is used for grading follicular lymphomas?

22.  This picture shows a lymphoma composed of neoplastic cells resembling monocytoid B cells. Which one is it?

23.  A 60-year-old man presents with rapidly enlarging axillary lymph nodes. A node biopsy shows the atypical lymphocytic population depicted in this photomicrograph. Neoplastic cells express CD19, CD20, CD79a, PAX-5, and CD10, while they are negative for CD5 and surface immunoglobulins. Which of the following is this type of lymphoma?