A 5-year-old boy is brought to the clinic by his parents for evaluation of constipation and a visible mass at the base of his spine. Physical examination reveals a firm, non-tender 4×5 cm sacrococcygeal mass. Vital signs are within normal limits. MRI shows a mixed-density lesion at the sacrococcygeal junction without spinal canal involvement. Histopathology demonstrates mature bone, striated muscle, cartilage, and ciliated respiratory epithelium. Which of the following embryologic abnormalities best explains the origin of this tumor?
- A)Failure of primordial germ cells to complete migration from the dorsal mesentery to the gonadal ridge
- B)Incomplete regression and migration of the tail bud and caudal epiblast during weeks 4-8 of developmentGABARITO
- C)Aberrant lateral plate mesoderm differentiation during somitogenesis
- D)Failed delamination of neural crest cells from the neural tube
- E)Abnormal endoderm invagination at the primitive pit during gastrulation
Explicação
Sacrococcygeal teratomas (SCTs) arise from pluripotent cells of the caudal epiblast and primitive streak that normally regress and migrate during tail bud involution (weeks 4-8). When these cells fail to regress and differentiate in situ, they form a germ cell... Ver explicação completa e trilha adaptativa →