A frontal lobe neoplasm might present with an array of symptoms that are collectively included in the "frontal lobe syndrome". Personality and abrupt emotional changes (aggression, apathy, impulsive behavior), and an overall decline of the functions for which the frontal lobe is crucial - planning, judgment, attention, memory, concentration- are some of the main findings. The diagnosis can be made through a detailed clinical investigation, followed by imaging studies, such as computed tomography (CT), but more commonly magnetic resonance imaging (MRI).
The clinical presentation of a frontal lobe neoplasm comprises various symptoms related to the tasks that the frontal lobe is responsible for - planning, organization, critical thinking, and most importantly, cognition    . The term "frontal lobe syndrome" is often used to depict the signs and symptoms observed in these patients  . Personality and mood changes are one of the most prominent findings in the setting of a frontal lobe neoplasm and manifest as uncharacteristically impulsive behavior, bouts of aggression, hypersexuality, apathy, or a combination of all    . Depression, paranoia, and/or mania is commonly encountered patients with frontal lobe neoplasms     . Loss of memory and/or focus, withdrawal from social life, and a reduced capacity for judgment are other notable signs of frontal lobe dysfunction . Some authors have established that specific symptoms arise as a result of damage to specific areas of the frontal lobe  . Namely, behavioral and personality deficits are most likely to occur if the prefrontal cortex is damaged, whereas cognitive dysfunction is highly indicative of an ongoing process in the dorsolateral region of the frontal lobe  . Loss of the sense of smell (anosmia) is another important sign that must include frontal lobe tumors in the differential diagnosis, particularly in the presence of behavioral or cognitive symptoms  .
The first and most important step of the diagnostic workup is a complete clinical assessment. A properly obtained patient history that determines the presence of even minor neurological deficits and a thorough physical examination that identifies these changes are sufficient to make a presumptive diagnosis. Both specific (anosmia, apraxia, and personality or cognitive deficits) and nonspecific (weight loss, improper sleep, anorexia, etc.) signs can point to an underlying process in the brain , providing sufficient evidence to employ imaging studies. CT and MRI are very useful for macroscopic evaluation of the brain and allow for the identification of a frontal lobe neoplasm in a short period of time . A CT scan is more feasible and is accompanied by less risk for patients compared to an MRI scan, but the latter is superior in visualizing neoplastic changes, particularly in the white matter . Although larger studies promote the argument against routine neuroimaging studies in the case of psychiatric changes that may include a brain tumor in the differential diagnosis, the physician is obliged to think of a possible organic cause of such symptoms, one of them being a neoplasm  . For further testing, MR spectroscopy, functional MRI (fMRI), positron emission tomography (PET), or single-photon emission computed tomography (SPECT) imaging may be used .