A Stepwise Approach to Macrocephaly: Clinical Clues to the Rare Diagnosis of PTEN Hamartoma Tumor Syndrome.

Macrocephaly, defined as a large head size, has a very broad differential and sometimes can be challenging to differentiate as benign versus indicative of pathology. In this review, we outline a stepwise approach to improving diagnosis of neurogenetic disorders versus other causes using the example of PTEN (phosphatase and TENsin homolog) Hamartoma Tumor Syndrome (PHTS). PHTS is a multiple hamartoma syndrome with medical management implications including the need for tumor surveillance, but often cases are not diagnosed until later in adulthood. Our review emphasizes the utility of using head circumference z scores in combination with other features as a triage tool for genetic identification of disorders such as PHTS.