Overview of Pituitary Tumors
Pituitary tumors are abnormal growths arising from the pituitary gland, a small endocrine organ located within the sella turcica at the base of the brain. Most are benign adenomas, but their size and hormonal activity can lead to significant clinical effects.
Pituitary tumors are generally classified as:
Functioning adenomas: Secrete excess hormones such as prolactin, growth hormone, or ACTH.
Non-functioning adenomas: Do not secrete clinically significant hormones but may cause mass effect.
Due to their proximity to the optic chiasm, these tumors frequently produce pituitary tumors headaches and visual disturbances.
Clinical Features
Hormonal Effects
Hyperprolactinemia: Galactorrhea, menstrual irregularities in women, hypogonadism in men.
Excess growth hormone: Acromegaly in adults, gigantism in children.
Excess ACTH: Cushing’s disease with weight gain, hypertension, and glucose intolerance.
Mass Effects
Persistent headaches due to tumor expansion (pituitary tumors headaches).
Visual field defects, typically bitemporal hemianopia.
Rare cranial nerve involvement in large adenomas.
Systemic Symptoms
Fatigue, weakness, and unexplained weight changes.
Hormonal imbalances causing menstrual irregularities, infertility, or metabolic disturbances.
Histopathology of Pituitary Tumors
1.Functioning Adenomas:
Prolactinomas: Prolactin-secreting tumors, known as prolactinomas, are the most prevalent type of pituitary adenoma and originate from lactotroph cells.
Somatotroph adenomas: Secrete growth hormone, causing acromegaly or gigantism.
Corticotroph adenomas: Secrete ACTH, causing Cushing’s disease.
Thyrotroph adenomas: Rare, secrete TSH leading to hyperthyroidism.
Gonadotroph adenomas: Usually non-functioning clinically, may secrete FSH or LH.
2.Non-Functioning Adenomas
Typically gonadotroph or null-cell adenomas.
Cause symptoms mainly through mass effect rather than hormone secretion.
3.Aggressive or Atypical Tumors
Atypical adenomas: Increased mitotic activity, high Ki-67 index, p53 positivity.
Pituitary carcinoma: Extremely rare, defined only by craniospinal or systemic metastasis.
Histological Features
Uniform cells with round to oval nuclei.
Sparse stroma with disrupted reticulin network.
Immunohistochemistry confirms hormone type: prolactin, GH, ACTH, TSH, FSH, LH.
Diagnostic Evaluation
Neurological and Ophthalmologic Examination: Visual field testing to detect optic chiasm compression.
Assessment of cranial nerves, motor function, and coordination.
Laboratory Testing: Blood tests for pituitary tumors to measure hormone levels: prolactin, GH, IGF-1, ACTH, cortisol, TSH, free T4, FSH, LH.
Screening for electrolyte imbalances and adrenal insufficiency.
Imaging Studies: MRI is the gold standard: tumor size, extension, and relationship to optic chiasm and cavernous sinus.
CT may be used if MRI is contraindicated.
Treatment Approaches
Management requires a multidisciplinary approach involving endocrinology, neurosurgery, radiology and ophthalmology.
1.Medical Therapy:
Dopamine agonists (cabergoline, bromocriptine) for prolactinomas.
Somatostatin analogs or GH receptor antagonists for acromegaly.
Hormone replacement therapy for deficiencies.
2.Surgical Intervention:
Transsphenoidal surgery with endoscopy method is preferred for most pituitary adenomas.
Provides decompression and allows histological diagnosis.
Pituitary tumor before and after images often demonstrate significant tumor reduction and relief of optic chiasm compression.
Postoperative MRI and hormonal assessment are essential.
3.Radiotherapy:
Considered for residual, recurrent, or aggressive tumors.
Stereotactic radiosurgery delivers focused radiation to minimize damage to surrounding structures.
Prognosis
Most pituitary tumors are benign; long-term outcomes are favorable with proper management.
Prognosis depends on tumor type, size, and completeness of resection.
Recurrence is possible, requiring ongoing MRI monitoring and blood tests for pituitary tumors.
Conclusion
Pituitary tumors are complex lesions with both hormonal and mass-related effects. Early recognition of pituitary tumors symptoms, including headaches, visual changes, and endocrine disturbances, is vital. Management requires a multidisciplinary team, integrating surgery, medical therapy, radiotherapy, and hormone replacement. Monitoring through imaging and laboratory tests ensures long-term tumor control and optimal quality of life. Pituitary tumor before and after assessments are key to evaluating treatment success and guiding further care.