When Benign Is Not Simple: Suspicious Thyroid Scintigraphy Revealing PTEN Hamartoma Tumor Syndrome in a Pediatric Patient.

PTEN hamartoma tumor syndrome (PHTS) encompasses a group of inherited disorders caused by germline mutations in the PTEN gene, which functions as a tumor suppressor. We report the case of a 10-year-old girl presenting with neck swelling. Initial ultrasound revealed nodular changes in the thyroid gland. Laboratory results indicated a euthyroid state, with normal calcitonin levels. However, thyroid scintigraphy demonstrated markedly pathologic findings, including cold, nonfunctioning nodules, raising suspicion for an underlying neoplastic or syndromic cause. This prompted further investigation through biopsy and molecular analysis, which confirmed a pathogenic PTEN mutation, establishing the diagnosis of PHTS.