Syphilis is a systemic disease caused by the spirochaete Treponema pallidum that affects the central nervous system at any time and whose clinical presentation has undergone changes in recent decades, due to the emergence of the acquired immune deficiency virus. We present the case of a 50-year-old immunocompetent woman with no significant changes in sexual behaviour, who only presented with headache and speech disturbances (mixed aphasia). MRI and CT scans initially showed left parietal injury, and later left temporal recurrence. The patient was treated for neurosyphilis for 5 weeks and showed improvement at her one-month follow-up appointment, before once again manifesting speech disturbances with sensory aphasia six months after treatment onset. Another control MRI was performed, revealing a relapse of the tumour lesion in the left temporal region. Intravenous treatment was once again initiated with benzathine penicillin and new serological and imaging tests were conducted, revealing the absence of lesions. Gummatous neurosyphilis is a rare condition, which explains why it tends to be erroneously diagnosed and treated. It is for this reason that we have presented our case study and literature review.