“… 4 In the latter form of transmission, cancer cells, or precursor cells spread hematogeneously to the body of the fetus. To date, only the following three different etiologies of transplacental cancer transmission have been reported: (1) maternofetal transmission of maternal cancer cells, 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 (2) transmission of gestational choriocarcinoma to the fetus, 23 , 24 , 25 , 26 and (3) the transfer of preleukemic cells from one monozygotic twin to the other (Figure 1 and Table 1 ). 27 , 28 , 29 , 30 , 31 , 32 Recently, we reported two pediatric cases of lung tumors, in which the lung‐only distribution of tumors and genomic profiling of both the child and mother's tumor samples suggested the transbronchial/airway transmission of maternal cervical cancer to the child through the aspiration of amniotic fluid, secretions, or blood from the cervix during vaginal delivery.…”