Abdominal mass: "fetus in fetu"

Fetus-in-fetu form of monozygotic twinning with retroperitoneal teratoma

One of the commonest defects of blastogenesis is monozygotic twinning resulting in separate or conjoint twins, the latter including a category of internal, "endoparasitic," or fetus-in-fetu twins. We report the third known instance of endoparasitic twinning associated with a benign teratoma at age 1. The host, twin, and teratoma were monozygotic by DNA analysis.

Fetus-in-fetu: a case report and review of the literature

A unique case of intraperitoneal fetus-in-fetu attached to an ovary is presented. An asymptomatic newborn girl was found to have a mobile cystic mass in right side of her abdomen. Radiological investigations showed fetus-in-fetu. During laparotomy, an intraperitoneal fetus-in-fetu was found attached to right ovary and vascular pedicle to ovarian vessels. Only 79 cases of fetus-in-fetu have been reported, and this is the first such case attached to an ovary.

Fetus in fetu: molecular analysis of a fetiform mass

Fetus-in-fetu is a rare condition presenting as a calcified intra-abdominal mass in the newborn infant. Over 50 cases of fetus-in-fetu have been reported since 1800. Karyotype analysis in 8 cases and protein polymorphisms in 4 documented identical findings in the host and fetiform mass. We report a case of fetus-in-fetu in a newborn female including cytogenetic and molecular studies of both the host and mass. Genotypic information from 7 polymerase chain reaction (PCR) assays representing 4 chromosomes demonstrates heterozygous and identical alleles in the infant and fetus-in-fetu at all loci studied. A review of the literature is provided including a discussion regarding the impact of molecular data on present hypotheses of fetus-in-fetu pathogenesis.