We report an autopsy case of congenital monoblastic leukemia that developed in monozygotic twins. The twin presented with progressive hepatosplenomegaly at 4 weeks after birth. One twin died of massive bleeding and hypovolemic shock before the treatment started. At autopsy, the liver was diffusely enlarged and showed a diffuse whitish discoloration except for the subcapsular and perivenular areas. Microscopic examination disclosed infiltration of histiocyte-like atypical cells along the sinusoids and portal areas of the liver. Spleen, lymph nodes and choroid plexus were also infiltrated by the tumor cells. However, bone marrow involvement of the tumor was minimal although multifocal. On immunohistochemical staining, these atypical cells were reactive for CD68 (PGM-1) and lysozyme, suggesting that the tumor cells might have been derived from mono- histiocyte. Cytogenetic study revealed 9;11 translocation, which is frequently associated with acute monoblastic leukemia. To the best of our knowledge, this is the first report of congenital monoblastic leukemia of monozygotic twins in Korea.
*Chromosomes, Human, Pair 11 ; *Chromosomes, Human, Pair 9 ; *Diseases in Twins/genetics ; Fatal Outcome ; Female ; Hepatomegaly/complications/genetics/pathology ; Human ; Infant, Newborn ; Leukemia, Monocytic, Acute/complications/*congenital/genetics/pathology ; Liver/pathology ; Splenomegaly/complications/genetics/pathology ; *Translocation (Genetics) ; *Twins, Monozygotic/genetics

OBJECTIVETo analyze the clinical characteristics of three Chinese cases of Niemann-Pick disease type C patients with neonatal cholestasis as initial presentation, and enhance awareness of Niemann-Pick disease type C among pediatricians.

METHODThree sporadic cases with confirmed Niemann-Pick disease type C initially presented as neonatal cholestasis were retrospectively reviewed in this study. Their peripheral blood specimens were collected after obtaining informed consent. All exons and the intron-exon boundaries of NPC1 gene were examined by bi-directional sequencing.

RESULTThree patients, 1 female and 2 males, aged from 2 months to 5 years and 10 months, all first complained of jaundice in the neonatal period. Laboratory tests showed total bilirubin and direct bilirubin significantly increased with predominant increase of direct bilirubin. Total bile acid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were also increased, while high-density lipoprotein cholesterol decreased. All patients were also accompanied by hepatosplenomegaly, with two of them having increased bronchovascular markings in chest X-ray. Two heterozygous changes of NPC1 gene, c.2741G>T +c.3020C>G (p. C914F + p. P1007R), c.2177G>C + c.3734_ 3735delCT (p.R726T + p. P1245RfsX12), and c.2054T>C + c.2128C>T(p.I685T + p.Q710X), were identified in patient 1, 2 and 3, respectively.

CONCLUSIONWe reported three cases suffered from Niemann-Pick disease type C with initial presentation as neonatal cholestasis in the mainland of China. For newborns with prolonged jaundice in the neonatal period, as well as neonatal cholestasis, hepatosplenomegaly, Niemann-Pick type C should be included in consideration of differential diagnosis. Genetic testing can identify causative mutations for diagnosis.

Asian Continental Ancestry Group ; Bile Acids and Salts ; Bilirubin ; Child ; Child, Preschool ; China ; Cholestasis ; etiology ; Exons ; Female ; Humans ; Infant ; Infant, Newborn ; Infant, Newborn, Diseases ; Lipoproteins, HDL ; Male ; Mutation ; Niemann-Pick Disease, Type C ; complications ; diagnosis ; genetics ; pathology ; Niemann-Pick Diseases ; Retrospective Studies ; Splenomegaly