Widespread invasion of a giant prolactinoma via valveless venous channels: illustrative case

Sep 29, 2026

Widespread invasion of a giant prolactinoma is examined through an illustrative neurosurgical case report. A 26-year-old man incidentally discovered to have an extensive pituitary mass showed radiographic invasion into both cavernous sinuses, the right orbit, bilateral retroclival space, and the right jugular foramen, with extension into a dilated right superior ophthalmic vein. Markedly elevated prolactin confirmed giant prolactinoma. Cabergoline achieved effective treatment without surgery, and the report emphasizes thorough imaging and endocrine assessment before operative decisions.

LanguageEnglish

CategoryHealthcare

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Pages4

Reading Time10 min

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Case Lessons

Background

Observations

Lessons

Illustrative Case

JOURNAL OF NEUROSURGERY: Case Lessons J Neurosurg Case Lessons 11(1): CASE25891, 2026 DOI: 10.3171/CASE25891 Widespread invasion of a giant prolactinoma via valveless venous channels: illustrative case Allison S. Liang, MD,1 Jeffrey L. Nadel, MD, MS,1 Madeleine de Lotbiniere-Bassett, MD, MS,1 Karen L. Salzman, MD,2 and William T. Couldwell, MD, PhD1 1Department of Neurosurgery, Clinical Neurosciences Center, and 2Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah BACKGROUND Approximately 35% of pituitary adenomas that require surgical intervention are invasive, often extending into the cavernous sinus (CS) via dural wall defects. Given the connections between the CS and multiple valveless venous plexuses in the orbit, face, and clivus, hematological venous spread is plausible, but the pathway by which these tumors locally invade remains uncertain. OBSERVATIONS A 26-year-old man with right eye proptosis who presented for trauma was incidentally found to have an extensive pituitary mass. The lesion demonstrated invasion into both CSs, the right orbit, the bilateral retroclival space, and the right jugular foramen, with radiographic extension into a dilated right superior ophthalmic vein. Laboratory workup revealed a markedly elevated prolactin level of 18,178 ng/mL (normal: 2.10–17.70 ng/mL), consistent with a giant prolactinoma. He was treated effectively with cabergoline and without surgery. LESSONS To the authors’ knowledge, this is the first documented case illustrating extensive venous-mediated spread of a pituitary adenoma through valveless venous networks involving the CS, orbital, and clival regions, and it provides a plausible mechanism for the enhanced invasive nature of prolactin-secreting tumors. This case underscores the need for thorough imaging and endocrine evaluation before considering the surgical management of suspected invasive pituitary lesions. [https://thejns.org/doi/abs/10.3171/CASE25891](https://thejns.org/doi/abs/10.3171/CASE25891) KEYWORDS prolactinoma; pituitary tumor; superior ophthalmic vein; cavernous sinus; case report Pituitary adenomas are benign tumors with a point prevalence of 80–175 per 100,000 persons1,2 that are characterized as either noninvasive (i.e. , confined to the sella) or invasive (i.e. , with extrasellar extension) . As many as 35% of pituitary adenomas requiring operative intervention are invasive.3 The sites of extrasellar extension may include the surrounding dura mater, bone, nasal sinuses, cavernous sinuses (CSs), and suprasellar spaces.3–5 CS involvement is common, and multiple classification schemes have been proposed, including those developed by Knosp and Hardy.4,6 It is unclear what separates the pituitary gland and CS anatomically. Some describe the presence of a thin collagen layer called the pituitary capsule, whereas others report a multilayer connective tissue barrier that includes the lamina propria, pituitary capsule, and an interconnected fibrous layer.4 Historically, pituitary adenomas were believed to spread into the CS as a result of defects in these barriers. Today, other theories have emerged about potential mechanisms of invasive spread, such as through the cisternal segment of cranial nerves III and IV7 or through the venous plexus of the superior orbital fissure.4,8–10 It is likely that these tumors spread via connections between the CS and neighboring venous plexuses, given their anatomical proximity.11 Illustrating this theory, we present the case of patient who was incidentally diagnosed with a giant pituitary macroadenoma—determined to be a prolactinoma—that demonstrated extensive invasion into the bilateral CS, right orbit, retroclival space, and right jugular foramen. Illustrative Case A 26-year-old man without a significant family medical history was evaluated in an emergency department in rural Montana after falling off a ladder and striking his head. At that time, he did not hav

FAQs

What tumor mechanism is proposed in this case report?

The authors propose extensive venous-mediated spread of a pituitary adenoma through valveless venous networks connecting the cavernous sinus with orbital and clival regions.

What key findings defined the diagnosis?

Imaging showed invasion into both cavernous sinuses, the right orbit, retroclival space, and the right jugular foramen, while laboratory testing revealed markedly elevated prolactin consistent with a giant prolactinoma.

How was the patient treated and what was the outcome?

The patient was treated effectively with cabergoline and did not require surgery, with the report highlighting that endocrine and imaging evaluation can guide management of suspected invasive lesions.

Sep 29, 2026

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