Poland Syndrome with transverse upper limb deficiency: beyond the vascular disruption hypothesis.

Poland syndrome classically presents with unilateral pectoral deficiency and ipsilateral symbrachydactyly. We report a neonate with right pectoral deficiency and carpal-level transverse upper limb deficiency without ectodermal elements. This rare phenotype challenges a single-point vascular interruption and supports a dynamic embryonic capillary plexus model.Level of Evidence: IV.