PHACEing a challenging diagnosis: Should we expand the phenotype?

Area of Science:

• Prenatal imaging and diagnosis
• Pediatric neurology
• Developmental biology

Background:

• PHACE syndrome is a complex prenatal diagnosis with significant clinical implications.
• The 'tilted telephone receiver' sign (TTRS) on prenatal imaging is highly specific for PHACE syndrome.
• An expanded PHACE phenotype has been proposed to improve prenatal detection.

Observation:

• A case presented with imaging findings similar to the proposed expanded PHACE phenotype: mild upward vermis rotation, asymmetric cerebellar volume loss, and a cerebellar cleft.
• This patient did not have PHACE syndrome postnatally.
• Infant neurodevelopmental testing revealed mildly atypical development.

Findings:

• Prenatal imaging findings consistent with an expanded PHACE phenotype do not always indicate PHACE syndrome.
• The presence of asymmetric cerebellar hemispheric volume loss, a cleft in the smaller hemisphere, and mild upward vermis rotation may not be specific for PHACE.

Implications:

• Expanding the PHACE phenotype may lead to erroneous adverse prenatal counseling.
• Careful consideration of imaging findings is crucial to avoid misdiagnosis and inappropriate prognostic counseling.
• Further research is needed to refine diagnostic criteria for PHACE syndrome and its related imaging findings.