Thyroidectomy or removal of the thyroid gland can be done for benign pathologies like multinodular goiter or malignant tumors like thyroid cancer. Removal of the parathyroid gland (or calcium gland) is the treatment of choice for calcium and parathormone imbalance caused by a dysfonction of one of the glands.
Procedures on the liver and pancreas are usually done when there is a benign tumor or cyst that is big enough to enduce pain. On the other hand, malignant tumors are removed by excision of a part of these organs.
Removal of the gallbladder is usually done when there is evidence of presence of stones by abdominal ultrasound, associated by chronic abdominal pain mostly after a meal.