Natural killer cell lymphoma: report of two pediatric cases, therapeutic options, and review of the literature.
BACKGROUND
Natural killer (NK) cell lymphomas are rapidly fatal malignancies that to the authors' knowledge are rare in children. In the current study, the authors report the cases of two boys with NK cell lymphomas with refractory disease who both were salvaged with high dose chemotherapy and stem cell transplantation and compare these patients with those in the published experience.


METHODS
A comprehensive literature review was performed to identify other cases of pediatric patients with NK cell lymphomas, their treatment, and outcome.


RESULTS
One of the patients in the current study developed two recurrences and the other patient experienced early disease progression during front-line treatment. Both then were treated with high dose chemotherapy followed by stem cell rescue. At last follow-up, the patients remained free of disease at 15 months and 16 months, respectively, after transplantation (48 months and 22 months, respectively, from the time of diagnosis). In addition to the 2 patients in the current study, the authors found 13 pediatric patients reported in the literature to date. Of the 7 patients with localized (Stage I-II) disease, 5 patients (71%) were reported to be alive 1-107 months after diagnosis. Of the 6 patients with Stage IV disease, only the 2 patients who received high dose chemotherapy and stem cell rescue (33%) were alive at the time of last follow-up (at 30 months and 12 months, respectively). Including the patients reported in the current study, 9 of 15 children with NK cell lymphoma (all stages) (60%) were reported to be alive at the time of last follow-up.


CONCLUSIONS
Although pediatric NK cell lymphomas rapidly can become fatal, it appears that high dose chemotherapy followed by stem cell transplantation is effective therapy, especially in patients with advanced or resistant disease. Further follow-up is needed to determine whether this treatment approach will be curative.
Department of Pediatrics, Northwestern University Medical School, Chicago, Illinois 60614, USA.
P H
PH
Shaw
S L
SL
Cohn
E R
ER
Morgan
P
P
Kovarik
P R
PR
Haut
M
M
Kletzel
S B
SB
Murphy
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D019002:CD56 Antigen; D002648:Child; D018380:Hematopoietic Stem Cell Transplantation; D004854:Herpesvirus 4, Human; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008223:Lymphoma / Q000276:immunology* / Q000628:therapy* / Q000821:virology; D008297:Male; D016879:Salvage Therapy
D019002:CD56 Antigen