Lactotroph Adenoma Surgery

Lactotroph Adenoma Surgery

Lactotroph Adenoma Surgery is safe and efficient. It is particularly suitable for enclosed prolactinomas. The patient should be well informed of the pros and cons of the treatment options, which include dopamine agonist (DA) and transsphenoidal microsurgery, and the patient’s preference should be taken into account during decision-making 1).

In the majority of prolactinoma patients, disease remission can be achieved through surgery, with low risks of long-term surgical complications, and disease remission is less often achieved with dopamine agonist2).

Prolactin level < 500 ng/ml in prolactinomas that are not extensively invasive: PRL may be normalized with surgery.


PRL > 500 ng/ml: the chances of normalizing PRL surgically are very low 3).

If no acute progression, an initial attempt of medical therapy should be made as the chances of normalizing PRL surgically with preop levels > 500 ng/ml are very low 4) (these tumors may shrink dramatically with bromocriptine).

If tumor not controlled medically (≈ 18 % will not respond to bromocriptine: surgery followed by restitution of medical therapy may normalize PRL).


Barrow et al. reviewed the results of transsphenoidal microsurgical management in 69 patients with prolactin-secreting pituitary adenomas who had preoperative serum prolactin levels over 200 ng/ml. The patients were divided into three groups based on their preoperative serum prolactin levels: over 200 to 500 ng/ml (Group A); over 500 to 1000 ng/ml (Group B); and over 1000 ng/ml (Group C). The percentage of successful treatment (“control rate”) was 68%, 30%, and 14%, respectively, in these three groups of patients. Based on these results, the authors offer guidelines for the management of patients with prolactin-secreting pituitary adenomas associated with exceptionally high serum prolactin levels. The surgical control rate of 68% in Group A seems to justify surgery for these patients, while primary medical care with bromocriptine is recommended for most patients with serum prolactin levels over 500 ng/ml 5).


Dopamine agonist therapy is the first line of treatment for prolactinomas because of its effectiveness in normalizing serum prolactin levels and shrinking tumor size. Though withdrawal of dopamine agonist treatment is safe and may be implemented following certain recommendations, recurrence of disease after cessation of the drug occurs in a substantial proportion of patients. Concerns regarding the safety of dopamine agonists have been raised, but its safety profile remains high, allowing its use during pregnancy. Surgery is typically indicated for patients who are resistant to medical therapy or intolerant of its adverse side effects, or are experiencing progressive tumor growth. Surgical resection can also be considered as a primary treatment for those with smaller focal tumors where a biochemical cure can be expected as an alternative to lifelong dopamine agonist treatment. Stereotactic radiosurgery also serves as an option for those refractory to medical and surgical therapy 6).


Many guidelines and reports that caution against surgical treatment are based on data over a decade or more old using different techniques such as microsurgical transsphenoidal surgery or from the nascent era of endoscopic transphenoidal surgery 7).

Endoscopic techniques have continued to evolve and provide for excellent visualization, low CSF leak rates, and high rates of gross total resection. In a study of DA-resistant prolactinomas, Vroonen et al. showed that surgical debulking led to a significant de- crease in prolactin levels at a significantly lower DA dose 8).

Kreutzer et al. report a remission rate of 91 % in patients who had elective surgery of microprolactinomas, and Babey et al. also had a high long-term remission rate, without morbidity or mortality for patients with microprolactinomas 9) 10).

Cost considerations are also a concern, especially in countries such as the USA, which is undergoing rapid changes in its healthcare system. A study by Jethwa and Patel et al. found surgical resection of microprolactinomas to be more cost effective long term than medical therapy 11).


Tumor size and invasion of extrasellar and/or cavernous sinuses have typically been seen as limitations of surgery, and some patients with refractory very large or giant tumors may necessitate multistage surgical procedures with a combi- nation of endonasal and transcranial approaches.

see Lactotroph adenoma radiosurgery.


Expanded endoscopic endonasal techniques have been developed that allow for safe treatment of larger adenomas that have extra-/parasellar extension as long as the extension is in the cranio-caudal direction and not lateral to the carotids. However, the issue of partial resection and the risk of apoplexy in the residual irritated tumor is of some concern. As in many other areas of neuro-oncology, a combination approach may be optimal. Surgical resection may allow for definitive removal of the tumor and relief of the mass effect and provide tissue for precisely targeted therapies to prevent recurrence. Sophisticated immunohistochemistry and genetic testing are rapidly being applied to many other tumors and may in the future allow for superior targeted adjuvant therapies in prolactinomas and help reduce recurrences. Finally, surgery might be an answer to the long-term cost of medical therapy specifically in younger patients. However, this issue should be carefully assessed on an individual basis to not jeopardize the standard of care in prolactinoma management by unnecessary surgical treatment. Medical treatment remains the first and the treatment of choice in the general population with recently diagnosed prolactinoma in the absence of rapidly progressive neurological symptoms 12).

Few studies address the cost of treating prolactinomas.

The Department of Neurological Surgery, University of California at San Francisco, performed a cost-utility analysis of surgical versus medical treatment for prolactinomas. Materials and Methods We determined total hospital costs for surgically and medically treated prolactinoma patients. Decision-tree analysis was performed to determine which treatment produced the highest quality-adjusted life years (QALYs). Outcome data were derived from published studies. Results Average total costs for surgical patients were $19,224 ( ± 18,920). Average cost for the first year of bromocriptine or cabergoline treatment was $3,935 and $6,042, with $2,622 and $4,729 for each additional treatment year. For a patient diagnosed with prolactinoma at 40 years of age, surgery has the lowest lifetime cost ($40,473), followed by bromocriptine ($41,601) and cabergoline ($70,696). Surgery also appears to generate high health state utility and thus more QALYs. In sensitivity analyses, surgery appears to be a cost-effective treatment option for prolactinomas across a range of ages, medical/surgical costs, and medical/surgical response rates, except when surgical cure rates are ≤ 30%. Conclusion Our single institution analysis suggests that surgery may be a more cost-effective treatment for prolactinomas than medical management for a range of patient ages, costs, and response rates. Direct empirical comparison of QALYs for different treatment strategies is needed to confirm these findings 13).


1)

Giese S, Nasi-Kordhishti I, Honegger J. Outcomes of Transsphenoidal Microsurgery for Prolactinomas – A Contemporary Series of 162 Cases. Exp Clin Endocrinol Diabetes. 2021 Jan 18. doi: 10.1055/a-1247-4908. Epub ahead of print. PMID: 33461233.
2)

Zamanipoor Najafabadi AH, Zandbergen IM, de Vries F, et al. Surgery as a Viable Alternative First-Line Treatment for Prolactinoma Patients. A Systematic Review and Meta-Analysis. J Clin Endocrinol Metab. 2020;105(3):e32‐e41. doi:10.1210/clinem/dgz144
3) , 4) , 5)

Barrow DL, Mizuno J, Tindall GT. Management of prolactinomas associated with very high serum prolactin levels. J Neurosurg. 1988 Apr;68(4):554-8. PubMed PMID: 3351583.
6)

Wong A, Eloy JA, Couldwell WT, Liu JK. Update on prolactinomas. Part 2: Treatment and management strategies. J Clin Neurosci. 2015 Oct;22(10):1568-74. doi: 10.1016/j.jocn.2015.03.059. Epub 2015 Aug 1. Review. PubMed PMID: 26243714.
7)

Casanueva FF, Molitch ME, Schlechte JA, Abs R, Bonert V, Bronstein MD, Brue T, Cappabianca P, Colao A, Fahlbusch R, Fideleff H, Hadani M, Kelly P, Kleinberg D, Laws E, Marek J, Scanlon M, Sobrinho LG, Wass JA, Giustina A (2006) Guidelines of the pituitary society for the diagnosis and management of prolactinomas. Clin Endocrinol 65:265–273
8)

Vroonen L, Jaffrain-Rea ML, Petrossians P, Tamagno G, Chanson P, Vilar L, Borson-Chazot F, Naves LA, Brue T, Gatta B, Delemer B, Ciccarelli E, Beck-Peccoz P, Caron P, Daly AF, Beckers A (2012) Prolactinomas resistant to standard doses of cabergoline: a multicen- ter study of 92 patients. Eur J Endocrinol 167:651–662
9)

Babey M, Sahli R, Vajtai I, Andres RH, Seiler RW (2011) Pituitary surgery for small prolactinomas as an alternative to treatment with dopamine agonists. Pituitary 14:222–230
10)

Kreutzer J, Buslei R, Wallaschofski H, Hofmann B, Nimsky C, Fahlbusch R, Buchfelder M (2008) Operative treatment of prolactinomas: indications and results in a current consecutive series of 212 patients. Eur J Endocrinol 158:11–18
11)

Jethwa PR, Patel TD, Hajart AF, Eloy JA, Couldwell WT, Liu JK (2015) Cost-effectiveness analysis of microscopic and endoscopic transsphenoidal surgery versus medical therapy in the management of microprolactinoma in the United States. World Neurosurg 5:2015
12)

Chakraborty S, Dehdashti AR. Does the medical treatment for prolactinoma remain the standard of care? Acta Neurochir (Wien). 2016 May;158(5):943-4. doi: 10.1007/s00701-016-2763-y. Epub 2016 Mar 11. PubMed PMID: 26965287.
13)

Zygourakis CC, Imber BS, Chen R, Han SJ, Blevins L, Molinaro A, Kahn JG, Aghi MK. Cost-Effectiveness Analysis of Surgical versus Medical Treatment of Prolactinomas. J Neurol Surg B Skull Base. 2017 Apr;78(2):125-131. doi: 10.1055/s-0036-1592193. Epub 2016 Sep 27. PubMed PMID: 28321375; PubMed Central PMCID: PMC5357228.

Cerebellopontine Angle Synchronous Tumor

Cerebellopontine Angle Synchronous Tumor

Synchronous cerebellopontine angle (CPA) tumors are a rare entity, heterogeneous lesions with a marked predisposition toward poor facial nerve outcomes, potentially attributable to a paracrine mechanism that simultaneously drives multiple tumor growth and increases invasiveness or adhesiveness at the facial nerve-tumor interface. Preceding nomenclature has been confounding and inconsistent; Graffeo et al. recommended classifying all multiple CPA tumors as “synchronous tumors,” with “schwannoma with meningothelial hyperplasia” or “tumor-to-tumor metastases” reserved for rare, specific circumstances 1).

Several publications refer to surgery for such tumors and their classification. Yet, there are no publications on upfront radiosurgery for synchronous CPA tumors.

Simultaneous and stepwise radiosurgery for synchronous CPA tumors seems to be safe and effective. There were no side effects or complications. To the best of our knowledge this is the first report on upfront radiosurgery for synchronous CPA tumors 2).

Mindermann and Heckl presented two patients with sporadic synchronous benign CPA tumors who underwent upfront radiosurgery. One patient had two separate schwannomas of the CPA and the other had a cerebellopontine angle schwannoma and a cerebellopontine angle meningioma. One patient underwent stepwise radiosurgery treating one tumor after another and the other patient underwent simultaneous radiosurgery for both tumors at the same time.

Simultaneous and stepwise radiosurgery for synchronous CPA tumors seems to be safe and effective. There were no side effects or complications. To the best of our knowledge this is the first report on upfront radiosurgery for synchronous CPA tumors 3).


A 64-year-old woman and a 42-year-old man presented with symptoms referable to the CPA. Magnetic resonance imaging in both patients revealed 2 separate contiguous tumors. Retrosigmoid craniotomy and tumor removal in each case confirmed VS and meningioma. Systematic literature review identified 42 previous English-language publications describing 46 patients with multiple CPA tumors. Based on Frassanito criteria, there were 4 concomitant tumors (8%), 16 contiguous tumors (33%), 3 collision tumors (6%), 13 mixed tumors (27%), and 11 tumor-to-tumor metastases (23%). Extent of resection was gross total in 16 cases and subtotal in 16 cases (50% each). Unfavorable House-Brackmann grade III-VI function was documented in 27% overall and in 33% of patients with VS and meningioma, a marked increase from the observed range in isolated VS 4).


A 57-year-old female patient presented with headache, speech disturbance, left facial numbness and deafness in the left ear. Magnetic resonance imaging demonstrated two different tumors in the left CPA. These tumors were not in continuity. The tumors were totally removed through the left suboccipital approach. Histopathological examination revealed that the large tumor was a vestibular schwannoma and the smaller was a meningioma. Neurofibromatosis was not diagnosed in the patient. No recurrence was observed at the end of 9 years after the operation. The simultaneous occurrence of vestibular schwannoma and meningioma in the CPA appears coincidental. This association must be kept in mind if two different tumors are detected radiologically in the same CPA 5).


1) , 4)

Graffeo CS, Perry A, Copeland WR 3rd, Giannini C, Neff BA, Driscoll CL, Link MJ. Synchronous Tumors of the Cerebellopontine Angle. World Neurosurg. 2017 Feb;98:632-643. doi: 10.1016/j.wneu.2016.11.002. Epub 2016 Nov 12. PMID: 27836701.
2) , 3)

Mindermann T, Heckl S. Radiosurgery for Sporadic Benign Synchronous Tumors of the Cerebellopontine Angle. J Neurol Surg A Cent Eur Neurosurg. 2020 Oct 21. doi: 10.1055/s-0040-1714424. Epub ahead of print. PMID: 33086420.
5)

Izci Y, Secer HI, Gönül E, Ongürü O. Simultaneously occurring vestibular schwannoma and meningioma in the cerebellopontine angle: case report and literature review. Clin Neuropathol. 2007 Sep-Oct;26(5):219-23. doi: 10.5414/npp26219. PMID: 17907598.

Anterior Inferior Cerebellar Artery Anomalies

Anterior Inferior Cerebellar Artery Anomalies

The anterior inferior cerebellar arteryposterior inferior cerebellar artery (AICAPICA) common trunk anomaly is reportedly one of the most common vessel variants in the posterior circulation 1).


A healthy 59-year-old male with a unilateral sporadic vestibular schwannoma.

The patient elected to undergo a translabyrinthine approach for resection of a vestibular schwannoma. An aberrant loop of AICA was encountered during the temporal bone dissection within the petrous part of the temporal bone.

The patient suffered a presumed ischemic insult resulting in a fluctuating ipsilateral facial paresis and atypical postoperative nystagmus.

MRI demonstrated an ischemic lesion in the vascular distribution of the right anterior-inferior cerebellar artery, including the lateral portion of the right cerebellar hemisphere, middle cerebellar peduncle, and bordering the right cranial nerve VII nucleus. His functional recovery was excellent, essentially identical to the anticipated course in an otherwise uncomplicated surgery.

This case highlights the irregular anatomy of the AICA as well as the importance of thorough neurological exams in the postsurgical lateral skull base patient 2).


Anomaly in which a segment of the anteroinferior cerebellar artery (AICA) is embedded in the dura or bone surrounding the subarcuate fossa, a small depression in the bone posterior to the internal acoustic meatus (IAM), through which the subarcuate artery enters the bone. This anomaly places the artery at risk in removing the posterior wall of the IAM.

An anomalous AICA having a segment that was embedded in the dura covering on the bone surrounding the subarcuate fossa was found during a microsurgical dissection course. The senior author (ALR) has observed this anomaly in four patients during surgery for acoustic neuromas and in three specimens in microsurgery dissection courses. To define the microsurgical anatomy of the anomalous artery further, the latex-injected specimen was dissected in a stepwise manner using x3 to x40 magnification.

The anomalous AICA described in this report bifurcated into a rostral trunk and a caudal trunk near the facial-vestibulocochlear nerve complex. The caudal trunk formed a sharp lateral loop that was embedded in the dura covering the subarcuate fossa. The involved trunk continued to supply the suboccipital area normally supplied by the posteroinferior cerebellar artery, which was hypoplastic. The dura surrounding the anomalous loop was opened, and the adjacent bone was removed to free the anomalous loop from the subarcuate fossa so that the artery could be displaced medially to remove the posterior wall of the IAM. Although it has been reported that the AICA may occasionally be adherent to the dura over the subarcuate fossa, this study is the first to demonstrate an AICA that is embedded in the dura and bone of the subarcuate fossa.

Mobilizing the AICA loop that is embedded in the subarcuate fossa posterior to the IAM places the involved AICA at significant risk in exposing the contents of the IAM 3).


Reports of hemifacial spasm (HFS) associated with AICA-PICA common trunk are very rare. In the present study, we describe methods of microvascular decompression (MVD) for HFS caused by AICA-PICA common trunk compression.

Among 159 patients who underwent MVD for HFS, 16 patients had compression of the root exit zone by the AICA-PICA common trunk anomaly. The types of compression were classified into 2 groups: common trunk artery compression group and branching vessel compression group.

The common trunk artery compression group consisted of 11 patients (69%), and the branching vessel compression group consisted of 5 patients (31%). The rostral branch (feeding the original AICA territory) coursed between the seventh and eighth cranial nerves in 5 patients, and in 13 patients (81%), the offending vessel harbored perforators around the root exit zone. Among 16 patients, 14 (87.5%) required interposition of the common trunk or the branching vessel, and in 2 patients, decompression was completed by the transposition method. Fifteen patients experienced sufficient results, and 1 had severe residual spasm. Transient facial palsy developed in 2 patients. No patients encountered recurrence.

Reports concerning decompression methods of AICA-PICA common trunk anomaly are very rare. The tortuosity of the common trunk and perforators from the offending vessel make the usual repositioning of the offending artery much more difficult, and adequate decompression techniques are required for successful MVD 4).

References

1)

Shimano H, Kondo A, Yasuda S, Inoue H, Morioka J, Miwa H, Kawakami O, Murao K. Significance of Anomalous Anterior Inferior Cerebellar Artery-Posterior Inferior Cerebellar Artery Common Trunk Compression in Microvascular Decompression for Hemifacial Spasm. World Neurosurg. 2016 Aug;92:15-22. doi: 10.1016/j.wneu.2016.04.100. Epub 2016 May 4. PMID: 27155382.
2)

Bauer AM, Angster K, Schuman AD, Thompson BG, Telian SA. Aberrant AICA Injury During Translabyrinthine Approach. Otol Neurotol. 2020 Sep 28. doi: 10.1097/MAO.0000000000002826. Epub ahead of print. PMID: 33003181.
3)

Tanriover N, Rhoton AL Jr. The anteroinferior cerebellar artery embedded in the subarcuate fossa: a rare anomaly and its clinical significance. Neurosurgery. 2005 Aug;57(2):314-9; discussion 314-9. PubMed PMID: 16094161.
4)

Shimano H, Kondo A, Yasuda S, Inoue H, Morioka J, Miwa H, Kawakami O, Murao K. Significance of Anomalous Anterior Inferior Cerebellar Artery-Posterior Inferior Cerebellar Artery Common Trunk Compression in Microvascular Decompression for Hemifacial Spasm. World Neurosurg. 2016 Aug;92:15-22. doi: 10.1016/j.wneu.2016.04.100. PubMed PMID: 27155382.
WhatsApp WhatsApp us
%d bloggers like this: