Tumor of the hormone-secreting pituitary gland increases the hormone prolactin production, resulting in the suppression of other hormones in the body due to the high level of prolactin hormone. Levels of estrogen and testosterone reduce in women and men, respectively, causing infertility in them. Prolactinoma can be minor prolactinoma or macroprolactinoma, based on the diameter of the tumor.
What is Macroprolactinoma?
Macroprolactinoma is a large size prolactinoma. Prolactinoma is benign lesions of the epithelial lining of the gland. In the pituitary gland, it is most common. Macroprolactinoma is more than 0.01m in diameter, and minor prolactinoma is smaller than 0.01m in diameter. Most of the time, prolactinomas are the minor ones; only 10% of the macroprolactinomas observed. But the majority functioning of the pituitary tumor is constituted by macroprolactinomas. Their behavior and distribution frequency also varies and majorly depends on the age and sex of the patient. It is the most common type of pituitary tumor in women aged 20 to 50 years.
The ratio of occurrence is significantly less in males. In preteens children, macroprolactinoma is rare, and if adenoma is there, it is does not function properly in children. In the diagnosis of macroprolactinomas, testing plays a significant role in providing information about the tumor’s size and its invasion of the other surrounding areas. Hormone testing includes serum PRL levels, serum pregnancy test in reproducing females. Serum TSH level helps in the determination of the free thyroxine level. Some other pituitary hormones are also measured as a workup. In imaging testing, magnetic resonance imaging (MRI) is the first choice to scan the pituitary gland’s tumors of soft-small tissue lesions. A computed tomography (CT) scan was also performed to diagnose the presence of a mass lesion. Follow-up testing is the same as in the initial assessment and repeated to check the patient’s effectiveness.
Signs and Symptoms appear due to hyperprolactinemia, and it varies in males and females. Macroprolactinoma compresses the normal hormone-secreting cells of the pituitary gland, resulting in a decreased amount of hormones. In females due to overproduction of hormone prolactin and reduction in estrogen (hypoestrogenism) level causes hormonal dysfunction and leads to disturbance in the menstrual cycle. It causes missing of the monthly periods (amenorrhea) or infertility and abnormal discharge from the breast (galactorrhea), vaginal dryness, and decreased bone mineral density, which is osteoporosis. In males, a suppressed level of testosterone causes infertility, erectile dysfunction, visual problems, headaches. Delayed puberty in female and male children in case macroprolactinoma develops prepubertally.
The exact causes are still unknown. But it is found that some factors are responsible for the growth of the tumor. Those patients having a family history of pituitary tumors are more at risk. Some specific conditions and particular medications are accountable for increasing prolactin and ultimately triggering the tumor’s production. Sometimes an accumulation of prolactin level is temporary and reversible. Conditions include pregnancy, breast stimulation, epileptic seizures, Hypothyroidism, renal failure, injury, or lesions in the chest wall, spinal cord lesions, adrenal insufficiency. Those drugs disturb the production and uptake of dopamine.
They may increase the level of prolactin in the body because, in the brain, dopamine helps in the blockage of prolactin production. Those types of drugs are risperidone, SSRIs from the class of antipsychotics, high blood pressure medicines like verapamil and methyldopa, medications for gastroesophageal reflux treatment nausea, and vomiting, cimetidine from h2 antagonist, and chronic opioids usage. Drug-associated hyperprolactinemia can be reversed by stopping the use of these responsible drugs. Other factors include exercise, diet, and sexual intercourse. For some Idiopathic reason, it found that the tumor grows on its own as well.
Treatment is required when a mass lesion develops in the pituitary gland or when the patient shows significant effects of macroprolactinoma. Bromocriptine is considered the first drug of choice in the treatment. It decreases the level and secretion of prolactin by working as a dopamine agonist and shrinks the size of the tumor leads to the better functioning of the pituitary gland. It has a long and safe, effective track. Visual findings, along with image findings, showed significant improvement after starting treatment.
Cabergoline is another long-acting dopamine agonist. The efficacy profile is better in comparison with bromocriptine, and side effects are fewer as well. Therapy gets fail if dopamine agonist faces some pharmacological resistance due to the presence of other drugs. Rarely radiation therapy is performed to obtain the normalized level of prolactin, Suggested only in those cases where rapid regrowth of tumors occur. Still, it has a less prominent effect and severe kind of complications than medical and surgical treatment. Surgical procedures in transcranial pituitary tumors are challenging and mostly unsuccessful due to the high mortality and morbidity rate. But still, it is considered as second-line treatment after medication.