ADRENAL TUMORS
Introduction
An adrenal is an endocrine gland located on the top of the upper pole of each kidney and secretes a range of hormones necessary for humans. The adrenal medulla produces adrenaline and noradrenaline, hormones which are important for regulating the nervous system. The cortical portion of the adrenal produces hormones such as cortisol, aldosterone and androgens. These hormones are necessary for regulating the homeostasis of the human body and immune response. The adrenal glands can be the growth area of adenomas (benign tumors) and malignant tumors. The adrenal adenomas are benign tumors which do not metastasize to other tissues. Nevertheless, most adenomas secrete large amounts of hormones causing hormonal imbalance with significant health effects for the patients. In contrast, malignant tumors of the adrenal gland are still considered rare but extremely aggressive form of cancer. Regardless of the type of the tumor (malignant or benign), increased hormone production remains one of the most threats of adrenal tumors. In all those cases removal of the adrenal gland (adrenalectomy) is indicated.
The prognosis depends on the stage of the disease. Small tumors in early stages can be cured (without any recurrence) in more than 90% of cases. When a total excision of the tumor by partial or radical nephrectomy has been performed and histology demonstrates that the tumor is located exclusively in the kidney, the 5-year survival ranges between 60-70%. In case of tumor extending outside the kidney or the presence of distant metastasis, the prognosis is poor.
The diagnosis of adrenal tumor is usually made due to the developed symptoms of hormone imbalance. The disease can also be incidentally diagnosed when examinations are performed for the investigation of another health problem. Abdominal ultrasound is the initial, safe and cost-effective imaging modality for diagnosis of adrenal tumors. However, computer tomography of the abdomen represents the most important tool for investigation and proper localization of adrenal tumors.
Surgical removal of the tumor or the affected gland is the main approach to treat the patients. Laparoscopic adrenalectomy (removal of the adrenal gland) is now the procedure of choice for the removal of functional adrenal adenomas such as pheochromocytoma and adrenal non-functioning tumors. Furthermore, the laparoscopic approach is indicated for the treatment of tumors suspicious for malignancy and secondary adrenal metastases from extra-adrenal tumors. The surgery is performed under general anesthesia with the use of small 5 to 10mm diameter instruments.
The main reason why laparoscopic approach for adrenelectomy is considered the treatment of choice is the significantly reduced morbidity compared to the open surgical approach. Three abdominal or lumbar incisions are necessary for the performance of the procedure. The operative time is approximately two hour and intraoperative blood loss is minimal. The tumor is removed at the end of the procedure by one of the incisions. The patient is mobilized and eats on the first day after surgery and leaves the hospital on the second day. After 10 days the patient is fully capable to return to pre-surgery activity. The aesthetic result is excellent.
Several surgical and endocrine complications are associated with laparoscopic adrenalectomy. Surgical complications are related to intra-operative bleeding, which is, however, when laparoscopic approach is used. Injury to adjacent organs is a rare complication when the surgery is performed in a specialized center with extensive experience. Hormonal complications are associated with intra-operative release of large amounts of hormones in blood circulation and postoperative adrenal insufficiency following the removal of the gland. The correct preoperative preparation and postoperative patient assessment by an experienced endocrine team as well as careful surgical manipulations minimize those complications.