Giant Pituitary Adenoma Presenting with Foster-Kennedy Syndrome in a 21-Year Old Ethiopian Patient: A Rarely Reported Phenomenon: A Case Report

BACKGROUND: Disorders of the pituitary gland and the sellar region present a wide spectrum of clinical problems. A variety of lesions in this area tend to present with similar problems; namely, headache, hormonal disorders, and loss of vision. Benign adenomas of the pituitary gland are by far the most common disorders of sellar region. Rarely, patients with pituitary adenoma may present with blindness in one eye and visual field cut (temporal hemianopia) in the contralateral eye. This rare clinical entity is called Foster-Kennedy Syndrome (FKS). CASE PRESENTATION: We present a 21-year-old male patient, presented with progressive visual disturbance of the left eye, associated with global headache. The headache was refractory to over-counter medications. In addition, he had history of sleep disturbance and loss of appetite. Neurological examination was pertinent for left side visual loss with optic atrophy and right eye temporal visual field cut with disc edema. Brain MRI showed 4 cm X 3.5 cm sized lobulated intra and supra sellar mass with heterogeneous contrast enhancement and minimal surrounding edema. Serum prolactin level was 6,705 ng/mL. Otherwise, the other pituitary hormones were in normal range. CONCLUSION: This case highlighted that pituitary adenoma may present with the full picture of Foster Kennedy syndrome. Therefore, we recommend considering pituitary adenoma as a possible differential diagnosis of intracranial lesions presenting as Foster Kennedy syndrome, as early detection and management could potentially salvage patients' vision and quality of life.