Abstract
Plasmacytoid dendritic cell (pDC) lymphoma is a disease entity in the WHO/EORTC cutaneous lymphoma classification. The pDC lymphoma co-expresses CD4 and CD56 without any other lineage-specific markers and has been identified as arising from pDC. In addition, pDC lymphoma is rare and characterized by a rapid aggressive course, with notable skin involvement and a frequent evolution towards overt leukemia. While this disease mainly affects the elderly, a few pediatric cases have been reported. In children, there are two distinct types that exist. These include an aggressive type that involves the skin similar to that seen in the adult type of the disease, along with a second type that is less aggressive and does not involve the skin or behave like acute leukemia. We describe the clinical and biological features of three pDC lymphoma children (Table 1). Morphologically, we observed a peculiar arrangement of the vacuoles along the cytoplasmic outline, the so-called pearl necklace appearance. The blast cells expressed CD4, CD56, HLA-DR, CD123 in three of the patients while BDCA-2 was noted in two patients (Table 2). After the initial AML-oriented therapy, two patients developed an early relapse and subsequently died; they were considered as aggressive type of pDC lymphoma. In our hospital, 3 of 22 patients with malignant lymphoma were diagnosed as pDC lymphoma for five years. In conclusion, the CD4+, CD56+, CD3−, CD13−, CD19−, CD33− phenotype is highly suggestive of pDC lymphoma. In the current cases, additional analyses using CD123 and BDCA-2 antibodies helped to confirm our initial diagnosis. Since an optimal therapy for pDC lymphoma in children is as of yet still unknown, a cooperative study needs to be undertaken to further investigate potential effective therapies for this disease.
Table 1. Clinical presentation of the patients with plasmacytoid dendritic cell lymphoma
| . | Patient 1 . | Patient 2 . | Patient 3 . |
|---|---|---|---|
| AraC, cytosine arabinoside; PSL, prednisone; VCR, vincristine; MTX, methotrexate | |||
| Year/Sex | 5/M | 9/M | 6/F |
| Skin lesion | + | + | + |
| Lymphadenopathy | − | − | + |
| WB C (×109/L) | 5.0 | 7.4 | 6.4 |
| Hemoglobin (g/dL) | 11.4 | 12.6 | 13.2 |
| Platelets (×109/L) | 284 | 294 | 264 |
| BM blast cells (%) | 13 | 0 | 0 |
| Initial therapy | AraC, etoposide | AraC, etoposide | PSL, VCR, MTX |
| Complete remission | + | + | + |
| Relapse | + | + | − |
| Survival (month) | 22 | 36 | 2 < |
| Outcome | Death | Death | Alive |
| . | Patient 1 . | Patient 2 . | Patient 3 . |
|---|---|---|---|
| AraC, cytosine arabinoside; PSL, prednisone; VCR, vincristine; MTX, methotrexate | |||
| Year/Sex | 5/M | 9/M | 6/F |
| Skin lesion | + | + | + |
| Lymphadenopathy | − | − | + |
| WB C (×109/L) | 5.0 | 7.4 | 6.4 |
| Hemoglobin (g/dL) | 11.4 | 12.6 | 13.2 |
| Platelets (×109/L) | 284 | 294 | 264 |
| BM blast cells (%) | 13 | 0 | 0 |
| Initial therapy | AraC, etoposide | AraC, etoposide | PSL, VCR, MTX |
| Complete remission | + | + | + |
| Relapse | + | + | − |
| Survival (month) | 22 | 36 | 2 < |
| Outcome | Death | Death | Alive |
Table 2. Immunophenotypes of the blasts with plasmacytoid dendritic cell lymphoma
| Surface marker . | Patient 1 . | Patient 2 . | Patient 3 . |
|---|---|---|---|
| NA, not available | |||
| CD3 | − | − | − |
| CD4 | + | + | + |
| CD7 | + | − | − |
| CD13 | − | − | − |
| CD19 | − | − | − |
| CD33 | − | − | + |
| CD34 | − | − | − |
| CD56 | + | + | + |
| CD123 | + | + | + |
| HLA-DR | + | + | + |
| BDCA-2 | + | NA | + |
| Surface marker . | Patient 1 . | Patient 2 . | Patient 3 . |
|---|---|---|---|
| NA, not available | |||
| CD3 | − | − | − |
| CD4 | + | + | + |
| CD7 | + | − | − |
| CD13 | − | − | − |
| CD19 | − | − | − |
| CD33 | − | − | + |
| CD34 | − | − | − |
| CD56 | + | + | + |
| CD123 | + | + | + |
| HLA-DR | + | + | + |
| BDCA-2 | + | NA | + |
Disclosures: No relevant conflicts of interest to declare.
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