Atypical pituitary adenoma with orbital invasion: Case report and review of the literature.

Pituitary adenoma invasion into the orbit is a rare phenomenon with only 22 cases, including the present case, in the literature. Our case is a 31-year-old man who presented with biopsy-proven atypical pituitary adenoma invading the right orbit after a prior resection. We compare his clinical course with previous cases and discuss clinical features, radiological features, management considerations, histologic features, and prognosis. Cases are organized by specific pituitary tumor type to aid in determining appropriate management. Early surgical intervention is the key, especially in the setting of pathologic features indicating aggressive tumor behavior or worsening visual function but is generally not indicated in prolactin-secreting adenomas that may respond to medical therapy. The role of radiation therapy is not fully established; however, it should be strongly considered in conjunction with or after surgery, especially in cases where complete resection is not achieved or histological and molecular analyses indicate a high likelihood of recurrence. More uniform and comprehensive data about management and outcomes are needed to determine the optimal treatment approach for this rare entity.