The peripheral blood smear shows lymphocytes with granular cytoplasm and irregular cytoplasmic contours (Images 1 and 2). The bone marrow aspirate and biopsy are moderately cellular with approximately 60% cellularity (Images 3 and 4). The erythroid maturation was slightly megaloblastoid (Image 5). Although there is decreased myelopoiesis, myeloid maturation is noted (Image 5). In addition, small lymphocytes with granular cytoplasm and irregular contours are identified (Image 6). The hematoxylin and eosin section of the bone marrow biopsy showed small clusters of lymphoid cells (arrow) and few scattered small lymphocytes (Image 7).
Immunohistochemistry was performed on the paraffin sections of the bone marrow biopsy specimen in order to identify the large granular lymphocytes and the following results were noted:
|CD 3||Positive cells in lines and rows (Image 8)|
|CD 20/L26||Scattered positive cells, small clusters and loose aggregates (Image 9)|
|CD 8||Negative (Image 10)|
|CD 57||Numerous positive cells (Image 11)|
|CD 56||Negative (Image 12)|
|TIA 1||Numerous positive cells (Image 13)|
|CD 7||Negative (Image 14)|
|CD 34||Highlights the blood vessels (Image 15)|
|CD 2|| Negative. (This may be due to the loss of antigens during the fixative
process of the bone marrow biopsy specimen)
|CD 5||Rare positive cells|
|Anti-kappa||Scattered positive plasma cells|
|Anti-lambda||Scattered positive plasma cells|
Flow cytometric immunophenotypic studies were performed on the bone marrow. They demonstrated a population of CD8 positive T-cells co-expressing CD57, CD2, CD7, CD3 and T-cell receptor alpha-beta. They however did not co-express CD16 or CD56. They had weak expression of CD 5 and few of the cells expressed CD4.
The diagnoses considered were:
T-cell receptor gene rearrangement was detected by PCR.