Pituitary Neuroendocrine Tumor (PitNET)

A Pituitary Neuroendocrine Tumor (PitNET), formerly known as a pituitary adenoma, is a tumor arising from the pituitary gland, a small endocrine organ located at the base of the brain. These tumors can be classified based on their hormone production: functioning PitNETs secrete excess hormones (e.g., growth hormone, prolactin, ACTH), while non-functioning PitNETs do not produce significant hormonal activity but may cause symptoms due to compression of nearby structures.

Synonyms: Pituitary adenoma (historical term), Pituitary tumor, Neuroendocrine tumor of the pituitary

Surgical Treatment: Endoscopic Transsphenoidal Resection

The standard approach for removing a PitNET is endoscopic transsphenoidal surgery, meaning the tumor is accessed through the nose (transsphenoidal route) without external incisions. This technique provides a minimally invasive route to the pituitary gland via the sphenoid sinus, reducing trauma to surrounding brain structures and leaving no visible scar on the head. The procedure is typically performed with an endonasal endoscopic approach, sometimes aided by neuronavigation and intraoperative imaging.

Depending on tumor size and extension, some cases may require a fat graft reconstruction, harvested from the abdomen or thigh, to seal the surgical cavity and reduce the risk of cerebrospinal fluid (CSF) leaks.

Postoperative Recovery & Monitoring

Patients typically recover in an intermediate care or intensive care unit (ICU) for the first 24–48 hours, depending on intraoperative findings and postoperative stability. Close monitoring is essential due to potential complications:

1. Fluid and Electrolyte Balance

• Diabetes insipidus (DI): A temporary or permanent condition caused by insufficient antidiuretic hormone (ADH), leading to excessive urination and dehydration.
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH): Can cause hyponatremia (low sodium levels), requiring careful fluid management.

2. Cerebrospinal Fluid (CSF) Leak & Wound Healing

• A CSF fistula (leak) may occur postoperatively, requiring bed rest, lumbar drainage, or revision surgery if persistent.
• If a fat graft was used, the patient will have a small secondary wound on the abdomen or thigh from the graft harvest.

3. Visual Follow-Up

• If the PitNET compressed the optic chiasm or optic nerves, leading to preoperative visual symptoms (e.g., bitemporal hemianopsia, reduced visual acuity, or color vision deficits), a postoperative ophthalmological evaluation is necessary.
• Visual function may improve, remain stable, or worsen postoperatively depending on the duration and severity of compression.
• Standard follow-up includes visual field testing and optic nerve assessment, often at 3 months postoperatively and periodically thereafter.

4. Imaging & Long-Term Follow-Up

• A postoperative MRI is typically performed around 3 months after surgery to assess residual tumor and healing.
• Endocrinological follow-up is essential, as some patients may develop hormonal deficiencies requiring hormone replacement therapy.

The transsphenoidal endoscopic approach has revolutionized pituitary surgery, allowing for quicker recovery, reduced complications, and no external scarring. However, careful long-term monitoring is required to assess for tumor recurrence, hormonal function, visual recovery, and potential late complications.

Disclaimer:

The above information is provided as general guidance and is not intended to replace individualized consultation with a qualified medical professional. The Luxembourgish Society of Neurosurgery and Spine Surgery a.s.b.l. (SLNCR) cannot be held responsible for the accuracy, completeness, or applicability of this information to specific cases, nor for any surgical outcomes, surgeon-specific approaches, or potential complications arising from the procedure. Patients are encouraged to discuss all details of their condition, treatment options, and potential risks directly with their surgeon.