Page 86 - The lraternational Journal of the Royal Society of Thailand.indd

The International Journal of the Royal Society of Thailand
Volume XV-2023

Figure 4 Diffuse growths in some specific entities of lymphoma. Diffuse growth by large lymphoma
cells in diffuse large B-cell lymphoma (A&B), starry-sky pattern with monotonous proliferation of
medium-sized lymphoma cells in Burkitt lymphoma (C&D), typical diffuse growth with hypervascularity
and admixed lymphoma cells with clear cytoplasm in nodal T follicular helper cell lymphoma,
angioimmunoblastic-type (E to G; G with PAS stain), and diffuse growth with pleomorphic medium to
large-sized lymphoma cells in peripheral T-cell lymphoma, not otherwise specified (H&I).

2) It is important to make sure that the lesion is lymphoma. The lymphoma cells should
demonstrate a clear immunophenotype – B-cell, T-cell, NK cell, or Hodgkin-Reed-
Sternberg (HRS) cell. If the immunophenotype of lymphoma cells can be established,

classifying lymphoma should not be a problem. Nevertheless, to obtain a definite
immunophenotype of the lymphoma cells is sometimes very difficult, especially in
the core needle biopsy. Sequence of immunostaining order is very important to

obtain information for making decision about the immunophenotype of the
lymphoma cells. For example, if the panel of immunostaining is limited to CD3,
CD20, and CD30 only, then the results show many large CD20+ B-cells in this
particular aggregate with occasional admixed apoptotic bodies containing
macrophages. It is very important to distinguish this aggregate of large B-cells

between reactive germinal center or aggregate of large lymphoma cells. At least 7
unstained slides for further immunostaining should be prepared at the time of
cutting slides for the first panel of immunostaining above. Then, immunostaining

for CD10, BCL2, BCL6, MUM1, and Ki-67 (total of 5 more tests) can be performed
for the true nature of this aggregate of large B-cells. If it is a dark zone of reactive

78 Reflections on How to Diagnose and Classify Lymphoma