Abstract

Background: A giant prolactinoma extending to the suprasellar area and causing hydrocephalus may be life-threatening and should be treated promptly. A case of a giant prolactinoma with acute hydrocephalus that underwent transventricular neuroendoscopic tumor resection followed by cabergoline administration is presented.

Case Description: A 21-year-old man had a headache lasting for about a month. He gradually developed nausea and disturbance of consciousness. Magnetic resonance imaging showed a contrast-enhanced lesion that extended from the intrasellar space to the suprasellar space and into the third ventricle. The tumor obstructed the foramen of Monro and caused hydrocephalus. A blood test showed marked elevation of prolactin (16,790 ng/mL). The tumor was diagnosed as a prolactinoma. The tumor in the third ventricle had formed a cyst, and the cyst wall blocked the right foramen of Monro. The cystic component of the tumor was resected using an Olympus VEF-V flexible neuroendoscope. The histological diagnosis was pituitary adenoma. The hydrocephalus improved rapidly and his consciousness became clear. After the operation, he was started on cabergoline. The tumor size subsequently decreased.

Conclusion: Prompt partial resection of the giant prolactinoma by transventricular neuroendoscopy resulted in early improvement of hydrocephalus with less invasiveness, allowing subsequent treatment with cabergoline.

Keywords: Endoscopy, Hydrocephalus, Prolactinoma

INTRODUCTION

A giant pituitary adenoma is defined as one that is >40 mm in its greatest dimension. It accounts for 5–15% of all pituitary adenomas.[ 14 ] Giant pituitary adenomas are often approached by extended transsphenoidal surgery or combined craniotomy and transsphenoidal surgery. Mortality from transnasal endoscopic surgery alone for giant pituitary adenomas has been reported to range from 1.4% to 7.1%. In the previous reports, the main causes of death were hemorrhage due to residual tumor and ischemic complications due to arterial injury.[ 1 , 2 , 7 ] On the other hand, prolactin (PRL)-secreting pituitary adenomas (prolactinomas) can be sufficiently reduced by oral administration of dopamine agonists alone. Therefore, even if the patient has a giant prolactinoma, there are few opportunities for surgery if the symptoms are not severe.[ 5 , 10 , 12 ] In the present case of a giant prolactinoma with life-threatening acute hydrocephalus, transventricular neuroendoscopic tumor resection was performed and followed by postoperative administration of cabergoline.

CASE PRESENTATION

A 21-year-old man with no medical history had a headache that lasted about a month. During the course, he experienced nausea and a mild disturbance of consciousness, and magnetic resonance imaging (MRI) was performed at a nearby clinic. The MRI showed a large tumor in the sella and surrounding region and he was referred to our hospital. His level of consciousness assessed by the Glasgow Coma Scale was 14 (E4 V4 M6). He had no significant visual disturbances at bedside examination. MRI taken at our hospital showed a contrast-enhanced lesion extending from the intrasellar area to the suprasellar area. The maximum tumor diameter was 53 mm. The cystic component of the tumor occupied the third ventricle and obstructed the foramen of Monro, causing acute hydrocephalus [ Figure 1 ]. A blood test showed a marked increase in PRL, up to 16,790 ng/mL (normal range: 3.7–16.3 ng/mL). The tumor was diagnosed clinically as a giant prolactinoma. The patient had acute obstructive hydrocephalus and needed quick surgical intervention. We considered that there was no time to wait for tumor shrinkage with the administration of dopamine agonists. Therefore, we decided to remove the tumor cyst to rescue the patient from hydrocephalus and make a histological diagnosis using a neuroendoscope.

Figure 1:

Magnetic resonance imaging T1-CE (contrast-enhanced) axial images (a-c), coronal image (d), and sagittal image (e). The tumor consists of a solid component and a cystic component, extending from the intrasellar turcica to the suprasellar turcica. It has also spread to both internal carotid arteries and the right cavernous sinus. The cystic components of the tumor (arrows) occupy the third ventricle causing acute hydrocephalus.

Surgical findings

The patient was placed in the supine position under general anesthesia. His head was set vertex up without rotation. A planned right anterior horn puncture was performed under navigational guidance [ Figure 2a ]. The pathway was then enlarged to insert a sheath (Neuroport mini, Hakko Co, Tokyo, Japan). A flexible endoscope (Olympus VEF-V, Olympus Co, Tokyo, Japan) was inserted into the ventricle to observe its interior. A purple cystic wall was observed blocking the right foramen of Monro [ Figure 2b ]. To communicate the left and right lateral ventricles, the septum was fenestrated with RAF electrodes (AIMS Co, Osaka, Japan) [ Figure 2c ]. Observation of the left lateral ventricle revealed that the left foramen of Monro was expanded by the tumor, larger than the right foramen of Monro [ Figure 2d ]. Therefore, the cyst removal was performed from the left side.

Figure 2:

(a): The route of entry of the flexible neuroendoscope is illustrated. First, the right ventricle was punctured (1) and then fenestration of the septum pellucidum was performed to enter the left ventricle (2). The cyst was then removed from the left foramen of Monro (3). (b): A purple-colored cystic wall blocking the foramen of Monro (asterisk) was observed. cp: Choroid plexus. (c) The septum pellucidum was fenestrated by RAF electrode. sp: septum pellucidum. (d) Left foramen of Monro enlarged by the cyst (asterisk). cp: Choroid plexus: Cyst wall is cauterized with RAF electrodes (e), and perforated with biopsy forceps (f). The cyst wall is excised with biopsy forceps (g). (h) Image of the third ventricle obtained after cyst removal. The mammillary body (white arrow) and aqueduct are confirmed (black arrow).

The cyst wall was cauterized with RAF electrodes [ Figure 2e ] and perforated using biopsy forceps [ Figure 2f ]. A yellow cystic fluid leaked out. The cyst wall was excised as much as possible with biopsy forceps [ Figure 2g ]. In addition, the cyst wall was cauterized with RAF electrodes to reduce the tumor volume. After the cyst had shrunk, the third ventricle was observed and the mammillary body and aqueduct could be identified [ Figure 2h ]. The operation was completed uneventfully.

Postoperative course

Cabergoline 0.25 mg was started orally every week from 2 days after surgery until now. Head CT taken 7 days after surgery showed improvement in acute hydrocephalus and reduction in ventricle size [ Figure 3 ]. He had no hormonal abnormalities or diabetes insipidus. The time course of basal levels of anterior pituitary hormones is shown in Table 1 . His consciousness also improved. He was discharged home 8 days after the operation. MRI taken 2 months later showed that the tumor had shrunk, and the hydrocephalus had disappeared [ Figure 4 ]. A blood test half year after surgery also showed a decreased PRL level to 443.7 ng/mL [ Table 1 ]. Sufficient tumor shrinkage can be expected from oral administration of cabergoline alone in the future.

Table 1:

Changes in basal levels of anterior pituitary hormones.

Figure 3:

CT on postoperative day 7, the tumor in the third ventricle has shrunk, and the acute hydrocephalus has resolved.

Figure 4:

Magnetic resonance imaging T1CE obtained 2 months postoperatively. The cystic component of the tumor disappeared, and ventricular enlargement was not observed. The solid component of the tumor shrank compared to the time of initial diagnosis.

DISCUSSION

Giant pituitary adenomas are often approached by extended transsphenoidal surgery or simultaneous craniotomy with transsphenoidal surgery. In endoscopic transsphenoidal surgery, it is difficult to remove tumors that have extended to the suprasellar area, ventricles, or cavernous sinus, and there is also a possibility of postoperative bleeding from residual tumors. It has been reported that simultaneous surgery is preferable because it may be possible to remove the tumor by adding craniotomy to transsphenoidal surgery. Simultaneous surgery with a transsphenoidal approach includes microscopic surgery,[ 4 , 8 , 16 ] transcranial surgery with a rigid endoscope,[ 6 , 11 , 13 ] and use of a tubular retractor[ 3 , 16 ] that have been reported. However, even among giant pituitary adenomas, prolactinomas are treated differently from the other giant pituitary adenomas. A giant prolactinoma is often seen in men and oral administration of dopaminergic drugs can be expected to sufficiently reduce the tumor; thus, drug therapy is the first choice.[ 5 , 10 ] Furthermore, dopamine agonists are recommended for the treatment of prolactinomas, including giant and invasive forms. This is because these agents inhibit the secretion and synthesis of PRL and the proliferation of lactotrope cells.[ 9 ] However, pituitary apoplexy in patients with prolactinomas with disturbance of consciousness and visual field disturbance may be an indication for surgery.[ 15 ] In the present case, a blood test showed an extraordinary increase in the PRL level and a preoperative diagnosis of prolactinoma was made. However, imaging findings showed associated acute hydrocephalus. Therefore, there was no time to wait for tumor shrinkage with oral dopaminergic drugs and it was thought that immediate surgical intervention was necessary to relieve hydrocephalus. If the tumor bulk itself obstructed the foramen of Monro causing hydrocephalus, simultaneous surgery with a transsphenoidal approach and a transcranial approach aimed at tumor decompression might have been considered, but it was expected to be highly invasive and risky. However, fortunately, from the preoperative MRI, it was assumed that the cystic component of the tumor obstructing the foramen of Monro caused the hydrocephalus. Therefore, transventricular resection of the tumor cyst was performed using a flexible neuroendoscope to relieve hydrocephalus and make a histological diagnosis. This method can be approached through a burr hole. The patient’s postoperative course was uneventful and his consciousness became clear, so the cabergoline could be started early. We also considered the use of bilateral ventricular drainage followed by cabergoline to allow the tumor to shrink. However, we have no idea when the tumor will shrink, the hydrocephalus will improve, and the drainage can be removed. In addition, by simply draining the ventricles, it is impossible to determine whether the tumor is malignant or not. Therefore, we chose an endoscopic approach that allows histological diagnosis and rapid improvement of hydrocephalus.

In addition, pituitary function was preserved in this case, so no postoperative hormone replacement therapy was required, and early discharge from the hospital was possible.

CONCLUSION

Rapid partial resection of a giant prolactinoma with cystic component by transventricular neuroendoscopy resulted in early improvement of hydrocephalus and allowed subsequent treatment with cabergoline.

Ethical approval and informed consent

This study was approved by the Ethics Committee of Kansai Medical University (No. 2020055). Need for written patient consent was waived by the Ethics Committee because data were deidentified.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Disclaimer

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.

References

1. Ceylan S, Sen HE, Ozsoy B, Ceylan EC, Ergen A, Selek A. Endoscopic approach for giant pituitary adenoma: Clinical outcomes of 205 patients and comparison of two proposed classification systems for preoperative prediction of extent of resection. J Neurosurg. 2022. 136: 786-800

2. Constantino ER, Leal R, Ferreira CC, Acioly MA, Landeiro JA. Surgical outcomes of the endoscopic endonasal transsphenoidal approach for large and giant pituitary adenomas: Institutional experience with special attention to approach-related complications. Arq Neuropsiquiatr. 2016. 74: 388-95

3. Guinto-Nishimura GY, Caballero-Delgado S, EguiluzMelendez AG, Ortega-Porcayo LA, Valencia-Ramos C, AragonArreola JF. Combined endoscopic transsphenoidal and tubular retractor-assisted transventricular approach for giant pituitary adenomas. World Neurosurg. 2021. 155: e761-9

4. Han S, Gao W, Jing Z, Wang Y, Wu A. How to deal with giant pituitary adenomas: Transsphenoidal or transcranial, simultaneous or two-staged?. J Neurooncol. 2017. 132: 313-21

5. Huang HY, Lin SJ, Zhao WG, Wu ZB. Cabergoline versus bromocriptine for the treatment of giant prolactinomas: A quantitative and systematic review. Metab Brain Dis. 2018. 33: 969-96

6. Koktekir E, Karabagli H, Ozturk K. Simultaneous transsphenoidal and transventricular endoscopic approaches for giant pituitary adenoma with hydrocephalus. J Craniofac Surg. 2015. 26: e39-42

7. Koutourousiou M, Gardner PA, Fernandez-Miranda JC, Paluzzi A, Wang EW, Snyderman CH. Endoscopic endonasal surgery for giant pituitary adenomas: Advantages and limitations. J Neurosurg. 2013. 118: 621-31

8. Matsumoto T, Ono T, Onodera T, Oda M, Takahashi M, Omae T. Transventricular preforniceal approach combined with endoscopic transnasal surgery for a giant pituitary adenoma: A case report and literature review. NMC Case Rep J. 2021. 8: 827-33

9. Melmed S, Casanueva FF, Hoffman AR, Kleinberg DL, Montori VM, Schlechte JA. Diagnosis and treatment of hyperprolactinemia: An endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2011. 96: 273-88

10. Moraes AB, Silva CM, Neto LV, Gadelha MR. Giant prolactinomas: The therapeutic approach. Clin Endocrinol (Oxf). 2013. 79: 447-56

11. Romano A, Chibbaro S, Marsella M, Oretti G, Spiriev T, Iaccarino C. Combined endoscopic transsphenoidaltransventricular approach for resection of a giant pituitary macroadenoma. World Neurosurg. 2010. 74: 161-4

12. Shimon I. Giant prolactinomas. Neuroendocrinology. 2019. 109: 51-6

13. Takeuchi K, Nagatani T, Watanabe T, Okumura E, Sato Y, Wakabayashi T. A purely endoscopic and simultaneous transsphenoidal and transcranial keyhole approach for giant pituitary adenoma resection: A technical case report. NMC Case Rep J. 2015. 2: 101-5

14. Tang OY, Hsueh WD, Eloy JA, Liu JK. Giant pituitary adenoma-special considerations. Otolaryngol Clin North Am. 2022. 55: 351-79

15. Witek P, Zielinski G, Maksymowicz M, Zgliczynski W. Transsphenoidal surgery for a life-threatening prolactinoma apoplexy during pregnancy. Neuro Endocrinol Lett. 2012. 33: 483-8

16. Yamada E, Akutsu H, Kino H, Tanaka S, Miyamoto H, Hara T. Combined simultaneous endoscopic endonasal and microscopic transventricular surgery using a port retractor system for giant pituitary adenoma: A technical case report. Surg Neurol Int. 2021. 12: 90