Treatment and Diagnostic Approach for Lhermitte-Duclos Disease and Suspected Cowden Syndrome.

Lhermitte-Duclos disease (LDD) is a rare entity, which may or may not be associated with Cowden syndrome (CS). The authors present a 26-year-old male with a history of emergency treatment due to acute obstructive hydrocephalus and apparent Chiari malformation. In posterior evaluation, mild cerebellar symptoms, mucocutaneous lesions, and a left hemispheric cerebellar lesion were evident. Initially, with the clinical evidence and the radiological study report of a cerebellar tiger-striped lesion, LDD with associated CS was suspected, and a genetic protocol was performed. The protocol included an endoscopy and thyroid ultrasound, and with symptom progression, a new neurosurgical procedure was performed. To complete the approach, we used the clinical criteria for PTEN hamartoma tumor syndrome established in 2013, and CS was diagnosed in the patient. In patients with radiological and clinical suspicion of LDD and CS, it should be mandatory to investigate the presence of other types of tumors due to their association with PTEN hamartomatous tumor syndrome, and in the absence of genetic study, the clinical criteria previously established in the literature should be sufficient to establish the diagnosis.