Case presentation
A 48-day-old female infant was firstly hospitalized at Nan children
Hospital of Nanjing medical University (Nanjing, China) in April, 2021,
with a complaints of increasing pallor sign from birth. Her mother had a
history of PIH during pregnancy. On the first day after birth, the
newborn was treated for fever in a local hospital. Blood routine tests
showed neutropenia with absolute neutrophil count (ANC) 0.04 × 109/l
with no periodic changes, mild anemia, and normal platelet count. She
also presented with non-pruritic, ecchymosis skin lesions on the
head,chest, trunk, and extremities after birth but got a self-remission
soon. At this time, laboratory evaluation demonstrated marked
neutropenia again with severe anemia (WBC, 0.91 × 109 /L; ANC ,0.02 ×
109 /L,hemoglobin, 3.3 g/dL; platelets, 212 × 109 /L). Coombs test were
negative. LDH level was normal. Physical examination revealed severe
anemia, while no skin lesions and lymphadenopathy were found.
She was treated by infusion of erythrocytes but complicated with a
severe allergic reaction. Blood transfusion was immediately stopped,
epinephrine and hydrocortisone were given, and transferred to ICU for
other life-supporting treatment.Anemia screening revealed ferritin
524ng/ml, folic acid and vitamin B12 at normal levels; reticulocyte
ratio and absolute count were within the normal range;We performed bone
marrow biopsy and without positive result. Based on the above
examination and the past medical history of the infant, we first ruled
out hemolytic anemia and nutritional deficiency anemia and chronic
disease anemia;We also completed peripheral blood whole exon gene
sequencing to rule out inherited metabolic diseases; while waiting for
the gene results, we continued the infant’s red blood cell transfusion
treatment and administered methylprednisolone before the transfusion to
prevent allergic reactions; the patient’s granulocyte deficiency status
gradually returned to normal after glucocorticoid administration.
Therefore, the infant was discharged from our hospital for the first
time and was instructed to be followed up on an outpatient basis. One
week after discharge, the child’s anemia worsened again. During this
recurrence, he was treated with methylprednisolone 10mg once a day daily
for four weeks, and hemoglobin gradually recovered again .At this point,
the whole-exon gene sequencing results suggested a mutation in the KMT2C
gene[Figure2] , but this was not sufficient to explain the
symptoms of allocytopenia in the infant.
She experienced a worsening bruise-purple nodular skin rash, and
pancytopenia two months later. BM smears demonstrated that blastic or
abnormal cells accounted for 3.5% of the nucleated
cells[Figure1 C/D] . Flow cytometry revealed a small
population of blasts in the dim CD45 positive blast gate that were
positive for CD4, CD56, CD123, and HLA-DR but the negative expression of
B, T, myeloid marker, and TdT[Figure2] . A skin biopsy was
done, and the results revealed diffuse dermal infiltrate with blast-like
cells extending to the hypodermis. Immunohistochemistry revealed cells
positive for CD4, CD31,CD68,CD43,CD56, and CD123 but negative for
CD3,CD20, MPO, TDT, CD34, and EBER, confirming the blastic plasmacytoid
dendritic cell neoplasm diagnosis[Figure1] . Her parents
disregarded the advice to take chemotherapy, and she died just a month
after being diagnosed.