Frontal lobe syndrome caused by a giant meningioma presenting as depression and bipolar disorder

Frontal meningiomas may present only with psychological symptoms that resemble depression, anxiety states, hypomania and schizophrenia. Herein, we present the case of a 55-year-old man who was initially thought to have depression and bipolar disorder, but was eventually diagnosed with frontal lobe syndrome caused by a giant frontal meningioma.