Surgical treatment of aggressive pituitary adenomas and pituitary carcinomas

Abstract

Surgery of aggressive pituitary adenomas and pituitary carcinomas is part of the interdisciplinary management of these difficult to treat tumors. Invasion, giant size and unusual, asymmetric extent of these tumors frequently require modifications or extensions of the standard approaches for transsphenoidal and transcranial surgery. Frequently, only debulking procedures can be performed. In aggressive and hormone secreting adenomas, the remission rates achieved by surgery alone are relatively poor and adjuvant medical treatments or irradiation are needed. Safe resection of as much tumor as possible and symptomatic control is aimed at, rather than remission. Many procedures are required for rapid progression of lesions or recurrences, in order to extend the survival of the patients. Metastases of pituitary carcinomas within the cranial cavity or spine can be attacked. Since they can occur anywhere in the brain or spinal canal they require the entire battery of neurosurgical approaches. Unfortunately, in this group of pituitary tumors, the complication rates are higher than in primary operations of enclosed adenomas. The respective techniques with their facilities and limitations are reviewed in this article.

Keywords: Aggressive growth; Cavernous sinus; Interdisciplinary management; Invasive adenoma; Pituitary carcinomas; Transcranial surgery; Transsphenoidal surgery.

Fig. 1

Rapid progression of a non-functioning pituitary adenoma in a 30-year-old female patient, as depicted on T1-weghted coronal MR images: a on presentation b delayed postoperative imaging 3 months after transsphenoidal surgery c follow-up investigation after 2 years d superimposing tumor structures onto operative field during repeat transsphenoidal surgery e delayed postoperative imaging after repeat surgery f RT-planning of residual tumor g most recent follow-up 5 years after conformal fractionated irradiation

Fig. 2

Invasive growth pattern of pituitary adenomas, encasing the internal carotid artery (✸) and optic nerve (arrow) (a) or growing and destroying along the anterior skull base and medial wall of the right orbit (b + c)

Fig. 3

Giant size is not a limit for tumour resection as long as there is a sufficient communication between intra- and suprasellar components (a+b). Depite of the large size, the tumor could be readily resected (c+d) as the delayed postoperative MRI shows

Fig. 4

A 48-year-old female patient presented with a large and invasive adenoma and a 3rd nerve palsy of the left eye (a). After transspehnoidal debulking surgery a supraclinoidal parasellar tumour (✸) persisted (b), which latter was resected via a fronto-temporal craniotomy (c)

Fig. 5

Limitations of transsphenidal tumor resection by cavernous sinus invasion: In this Knosp 4 grade tumour (a), the parasellar tumour portion could not be resected for the invasive nature of the adenoma, which has encased the intracavernous carotid artery (b)

Fig. 6

Progressive cerebral metastasis at the bottom of the right lateral ventricle of a PRL-secreting pituitary carcinoma (a). A small right frontal craniotomy (b) and transventricular approach (c) was chosen to resect the metastasis (d)

Fig. 7

Progressive spinal metastasis of a Proalctin-secreting pituitary adenoma. After first appearance (a) the metastasis showed a rapid progression (b). Intraoperative views (c + d) of the adherent metastasis. Despite irradiation and medical therapy with dopamine-agonists and temozolomide the spinal metastasis progressed continuously (e)