Non-B, Non-T Neoplasms With Lymphoblast Morphology

Abstract

We studied the morphologic, immunohistochemical, and clinical characteristics of 158 cases of lymphoblastic lymphoma. Based on immunophenotyping and cell lineage, cases were classified into B-cell type (CD20,CD19 or CD79a+, n = 53), T-cell type (surface CD3+, n = 84), and non-B, non-T type (B cell marker- and surface CD3-, n = 21). The latter group was further divided based on immunohistochemistry into: 1) CD7+ stem cell lymphoma (CD7+SCL) [CD4-, CD7+, CD33+/-, CD56-], 2) blastic natural killer cell lymphoma (B-NKL) [CD4-, CD7+/-, CD33-, CD56+, CD123-], 3) myeloid/NK precursor cell leukemia (M/NKL) [CD4-, CD7+, CD33+, CD56+], and 4) CD4+CD56+ hematodermic malignancy (CD4+CD56+) type [CD4+, CD7+/-, CD33-, CD56+, CD123+]. The CD7+SCL and M/NKL types frequently exhibited bone marrow invasion and mediastinal masses. All CD4+CD56+ types were associated with skin lesions. B-NKL type is included into Blastic NK lymphoma in new World Health Organization classification with CD4+CD56+ type. But the cases of B-NKL were more reminiscent of CD7+SCL or M/NKL type than the CD4+CD56+ type, both clinically and histologically. We propose that blastic NK lymphoma, a disease entity in the new WHO classification, should be divided into two types based on phenotypes and clinical features. The non-B, non-T lymphomas exhibited poorer prognoses, similar to that of B-cell lymphomas, than T-cell type tumors (P = 0.009). Among the 21 tumors, the prognosis of the four subtypes did not differ significantly; however, cases receiving aggressive chemotherapy and stem cell transplantation had a more favorable prognosis than those receiving only traditional chemotherapy and radiation therapy (P = 0.0089).

Expression of the plasmacytoid dendritic cell marker BDCA-2 supports a spectrum of maturation among CD4+ CD56+ hematodermic neoplasms

“…15 For example, variable expression of CD2, CD7, CD33, CD36, and CD68 has been demonstrated and a subset of cases display terminal deoxynucleotidyl transferase (TdT) immunoreactivity. 1,3,[16][17][18] Blood dendritic cell antigen-2 (BDCA-2) is a recently described cell-surface protein that is selectively expressed on plasmacytoid dendritic cells. 19 Primary amino-acid sequence homology suggests that BDCA-2 (CLEC4C, HECL, CD303) may act as a carbohydrate-binding protein of the C-type lectin family, although specific ligands have not been reported.…”

Effective Treatment of a Childhood Blastic Plasmacytoid Dendritic Cell Neoplasm with a Cutaneous Tumor Alone by Stem Cell Transplantation with Reduced Intensity Conditioning

“…But this report included not only BPDCN with lesion restricted to the skin. A summary of eight cases of pediatric BPDCN being initially limited to the skin is shown in Table 2 [17][18][19][20][21]. With only a few case reports of pediatric BPDCN being initially limited to the skin, treatment remains controversial and not standardized, especially.…”

“…Treatment related late toxicities such as infertility and growth deficiency and secondary malignant neoplasms have been reported in patients who received BMT with MAC. RIC regimens might be the preservation of fertility and the reduced risk of secondary malignant neoplasms [18]. Hence, the MAC regimen is preferably best avoided in children as for late toxicities.…”

Nucleolar Positivity for CD20

“…Eighty percent or more of lymphoblastic lymphomas are derived from precursor (thymic) T cells, and the reminder are derived from precursor B cells. 11 However, of the 158 lymphoblastic lymphomas classified by Karube et al 14 based on immunophenotyping and cell lineage in a recent study, 53 (33.5%) were B-cell type (CD20, CD19 or CD79α+), 84 (53.2%) were T-cell type (surface CD3+), and 21 (13.3%) were non-B, non-T type (Bcell marker− and surface CD3−). Of the 5 lymphoblastic lymphomas diagnosed by Sneige et al 4 in FNA smears, 2 each were of T-and B-cell phenotype.…”