A 62-year-old Caucasian man comes to the office with complaints of a dull, non-throbbing headache, hearing loss on the left side, and persistent tinnitus. His symptoms have been getting progressively worse for the last two weeks. He has a history of small cell cancer of the lung, which was treated with a combination of chemotherapy and radiotherapy four months ago. His lung mass has reduced considerably in size after its treatment. A contrast-enhanced magnetic resonance imaging scan shows a 1 x 2 cm circumscribed mass in the left cerebellopontine angle compressing the eighth cranial nerve. There is another small 0.5 x 1 cm mass in the left frontal lobe cortex with significant edema surrounding the lesion. Which of the following is the most likely cause of this patient's symptoms?

Question

A 62-year-old Caucasian man comes to the office with complaints of a dull, non-throbbing headache, hearing loss on the left side, and persistent tinnitus.  His symptoms have been getting progressively worse for the last two weeks.  He has a history of small cell cancer of the lung, which was treated with a combination of chemotherapy and radiotherapy four months ago.  His lung mass has reduced considerably in size after its treatment.  A contrast-enhanced magnetic resonance imaging scan shows a 1 x 2 cm circumscribed mass in the left cerebellopontine angle compressing the eighth cranial nerve.  There is another small 0.5 x 1 cm mass in the left frontal lobe cortex with significant edema surrounding the lesion.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

Explanation: Brain tumors are classified into tumors that originate in the brain itself (primary brain tumor), and those that originate elsewhere in the body and metastasize to the brain from another primary site (secondary brain tumor). Secondary brain tumors are the more common type of brain tumors. The common primary sites of origin of brain metastasis, in the order of frequency, are: lung, breast, unknown primary, melanoma, and colon cancer. Small cell lung cancer has a predilection for early metastasis to the brain. The most common route of spread of the cancer is by hematogenous spread. The diagnostic imaging of choice to evaluate a patient with suspected metastatic disease is a contrast-enhanced MRI scan. The clues to the presence of a metastatic brain lesion (as compared to a primary brain tumor) on radiographic imaging are the presence of multiple, well-circumscribed lesions, and a relatively large amount of vasogenic edema as compared to the size of the lesion. In the above vignette, the patient's symptoms is most likely being caused by a metastatic lung cancer which has compressed the eighth cranial nerve. Educational Objective: Metastatic lesions to the brain are the most common cause of brain tumors. These account for more than half of all the brain tumors seen in adult patients.

A 62-Year-Old Caucasian Man Comes to the Office with Complaints