functionless pituitary adenoma

A non-functioning pituitary adenoma (NFPA) is a type of benign tumor that arises from the cells of the pituitary gland, but does not produce excess hormones. These tumors are also known as clinically non-functioning pituitary adenomas or pituitary neuroendocrine tumours (NFpitNETs).

Characteristics:

• Benign in nature
• Do not produce excess hormones
• Can vary in size and growth rate
• May cause symptoms due to mass effect, such as visual disturbances, headaches, cranial nerve dysfunction, and hypopituitarism

Prevalence: The estimated prevalence of NFPA is 7-41.3 cases per 100,000 people, with an annual incidence of 0.65-2.34 cases per 100,000 [1-3].

Symptoms:

• Visual disturbances
• Headaches
• Cranial nerve dysfunction
• Hypopituitarism (underactive pituitary gland)
• Panhypopituitarism (complete underactivity of the pituitary gland)

Treatment: Surgery is the best form of treatment and the only way to achieve a cure. The transsphenoidal approach is commonly used, where the surgeon gains access to the pituitary gland through the sphenoid sinus [12].

Growth Rate: Most NFPA grow slowly, so surgical treatment can sometimes be delayed until symptoms occur.

References:

• [1] Kovacs K. (1991) The use of immunohistochemical techniques to determine the presence of α-subunit may provide information on tumor cell proliferation and biologic behavior.
• [2] Yavropoulou MP. (2020) Non-functioning pituitary adenomas, recently alternatively termed pituitary neuroendocrine tumours (NFpitNETs), are mostly benign neoplasms...
• [3] Asa SL. (1992) Clinically non-functioning pituitary adenomas are morphologically classified into two groups, those which have hormone immunoreactivity and ultrastructural...

Symptoms Caused by Mass Effect

Pituitary adenomas that do not produce hormones in excess (functionless or non-functioning) can still cause symptoms due to their mass effect on surrounding structures. These symptoms may include:

• Headaches [5]
• Visual disturbances, such as double vision or loss of vision [4, 8]
• Cranial nerve palsies [4]
• Weakness or numbness in the face or extremities [8]

These symptoms occur when the tumor grows large enough to press on nearby structures, such as parts of the brain, nerves, or other pituitary gland tissues.

No Symptoms

In some cases, functionless pituitary adenomas may not cause any noticeable symptoms and can be detected incidentally during a scan performed for another reason [3]. However, it's essential to monitor these tumors closely to prevent potential complications.

Diagnosis

If your doctor suspects a non-functioning tumor, you may need to undergo an MRI scan of the brain to determine the exact size and location of the tumor. Blood tests may also be performed to evaluate all levels of pituitary hormones [15].

References:

[3] - What are the signs and symptoms of pituitary tumours? [4] - ... signs secondary to mass effect, but without evidence for hormonal hypersecretion. [5] - by OM Dekkers · 2008 · Cited by 335 — The clinical signs and symptoms of clinically nonfunctioning macroadenomas are determined merely by mass effects of the tumor. [8] - by PJ Snyder · 1993 · Cited by 83 — Clinically nonfunctioning adenomas usually come to medical attention when they become so large that they cause neurologic symptoms, especially visual impairment ... [15] - Nonfunctioning Pituitary Adenoma Diagnosis.

Diagnostic Tests for Functionless Pituitary Adenomas

Functionless pituitary adenomas, also known as non-functioning or silent pituitary tumors, do not produce excess hormones that can be detected through blood tests. However, various diagnostic tests are used to confirm the presence of these tumors and rule out other conditions.

Imaging Tests

• MRI scans: Magnetic Resonance Imaging (MRI) scans are commonly used to detect pituitary adenomas, including functionless ones. They provide detailed images of the brain and pituitary gland, helping doctors locate the tumor [7][8].
• CT scans: Computed Tomography (CT) scans may also be ordered to produce images of the brain and pituitary gland for diagnostic purposes [9].

Blood Tests

While blood tests cannot directly detect functionless pituitary adenomas, they can help rule out other conditions that might cause similar symptoms. However, in some cases, blood tests may show slightly elevated levels of certain hormones, such as prolactin or IGF-1, which can be indicative of a pituitary tumor [5].

Other Diagnostic Tests

• Vision tests: Since pituitary adenomas can compress the optic chiasm and affect vision, visual field testing may be performed to assess any potential impact on vision.
• Biopsy: In some cases, a biopsy (tissue sample) of the tumor may be taken for further examination.

References

[1] Jun 29, 2024 - MRI scans are used more often than CT scans to detect and diagnose pituitary tumors. But a CT scan may be helpful in planning surgery if your ... [1] [2] Oct 10, 2022 - Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) blood levels can be checked to see if you have a gonadotropin-secreting tumor. [2] [3] An accurate pituitary tumor diagnosis usually involves hormone tests and an MRI scan of the pituitary gland. [3] [4] NYU Langone doctors diagnose pituitary tumors with blood and vision tests and MRI scans. Learn more. [4] [5] Nov 14, 2024 - The initial screening endocrine tests should include levels of prolactin, IGF-1, LH, FSH, TRH and alpha subunit, cortisol, and T4; men should ... [5] [6] by ME Molitch · 2017 · Cited by 1016 — Patients with pituitary adenomas should be identified at an early stage so that effective treatment can be implemented. [6] [7] Imaging tests: An MRI (magnetic resonance imaging) scan or CT (computed tomography) scan of your head can provide images of the structures inside of your head. ... [7] [8] Imaging tests, such as a magnetic resonance imaging (MRI) scan or computed tomography (CT) scan, to produce images of the brain and pituitary gland for ... [8] [9] Your health care provider may order blood and urine tests, CT scan, MRI, or biopsy to diagnose the tumor. Treatment may include surgery, radiation therapy, or ... [9]

Treatment Options for Functionless Pituitary Adenomas

Functionless pituitary adenomas, also known as non-functioning pituitary tumors (NFPTs), are a