Hematopathology Case Studies


CASE 3: Small lymphocytic lymphoma


Clinical History:

A 69-year-old man has noticed several lumps in his neck and axillae that have persisted over the past year. On physical examination, he has a palpable spleen and multiple medium-sized, rubbery, non-tender lymph nodes palpable in both sides of his neck, axillae, and inguinal regions. A CBC shows Hgb 11.1 g/dL, Hct 33.2%, MCV 85 fL, platelet count 109,000/microliter, and WBC count 24,800/microliter with WBC differential count 18 segs, 1 band, 79 lymphs, and 2 monos. His direct Coombs test is positive. A biopsy of an axillary lymph node is performed.
  1. What is the pattern of the lymph node observed under low power magnification?

    2. The pattern is diffuse and no lymphoid follicles are identified. Note that the normal architecture of the lymph node is obliterated.

  2. Under high power magnification, compare the appearance of the neoplastic cells to the few remaining normal lymphocytes present.

    3. Under higher power, the lymph node is replaced by small (mature-appearing) neoplastic lymphocytes, and these cells infiltrate through the capsule of the lymph node and into the surrounding adipocytes.

  3. What is your diagnosis in this case?

    4. The diagnosis is small lymphocytic lymphoma (SLL) in the WHO classification. This is histologically a low grade lymphoma, so it tends to be indolent, but it tends to involve multiple lymph node groups, as well as other organs such as spleen and liver and, thus, have a higher stage. SLL is a type of non-Hodgkin lymphoma (NHL) is seen in older adults, and it is often the tissue phase of chronic lymphocytic leukemia (CLL). Note that this patient has a lymphocytosis. Thus, he has CLL/SLL. Some of these patients develop an autoimmune hemolytic anemia and/or thrombocytopenia, as indicated by the positive Coombs test and the low platelet count in this case. Up to a third of patients may have transformation to a more aggressive form of lymphoma.

    The lymphoma cells typically mark for CD19, CD20, and CD5. The cells tend to express both BCL2 and BCL6. A karyotype may show chromosome deletions.