Prolactinoma Localization by Inferior Petrosal Sinus Sampling: Illustrative Case

Background: Inferior petrosal sinus sampling (IPSS) is a useful endovascular diagnostic procedure to distinguish between ectopic adrenocorticotropic hormone (ACTH) production and pituitary Cushing (Cushing’s disease). In this technique, the inferior petrosal sinuses are selectively catheterized to obtain baseline and stimulated ACTH levels from each side of the pituitary gland at the site of direct venous outflow. Measurement of, and adjustment to, simultaneously collected prolactin levels can improve diagnostic accuracy. The utility of IPSS outside of the differential diagnosis of ACTH-dependent hypercortisolism is uncommonly reported. In this study, IPSS was performed in a patient with hyperprolactinemia and two pituitary lesions.

Objective: The objective of this study is to describe the diagnostic utility of IPSS in a patient with hyperprolactinemia and bilateral pituitary lesions.

Methods: This abstract describes the case of a 37-year-old female with symptomatic hyperprolactinemia that was refractory to escalating dopaminergic medical management. MRI imaging demonstrated an 8-mm right-sided pituitary lesion and an anatomically distinct 5-mm left-sided pituitary lesion. IPSS was pursued in an attempt to localize the prolactin-secreting lesion.

Results: The IPSS data indicated the right-sided sellar mass was prolactin secreting. The patient underwent successful surgical resection of the right-sided adenoma, which was immunohistochemically positive for prolactin. She remains in remission 2.5 years out from surgery and without hypopituitarism.

Conclusion: We report the application of IPSS in a patient with hyperprolactinemia and bilateral pituitary tumors. This technique may be helpful in prolactinoma patients with multiple sellar masses.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
07 February 2025