Adrenal Tumor

Adrenal tumors are classified by nature (benign/malignant), by endocrine function (non-functioning/functioning, e.g. hormone secretion causing hypertension), and by site (cortical/medullary/stromal/metastatic). Clinically, surgically managed adrenal tumors are usually functioning or highly suspected malignant (or indeterminate pre-op). The adrenal gland is an important endocrine organ; because of its close anatomic relation to the kidney, it is traditionally a urologic disease. Humans have two adrenals, retroperitoneal, closely apposed to upper-medial kidneys. Shape/size resembles an adult's slightly bent little finger with head/body/tail; on close dissection the right adrenal is triangular and the left semilunar; right sits astride the medial right upper pole, left hangs from medial left upper pole. Dimensions: length 4.0-6.0 cm, width 2.0-3.0 cm, thickness 0.3-0.6 cm; normal weight ~4.0-5.0 g. Despite small gland size, tumors vary greatly: <3 cm = small tumor, smallest <1 cm, largest 10-30 cm. Shape may resemble bean, plum, apple, hami-melon or fetal head.

Common Symptoms

Limb weakness; foggy blurred vision; menstrual-cycle changes; fatigue; distal limb numbness; ...; low back pain; dizziness; amenorrhea

Causes and Pathogenesis

Cushing's syndrome: series of pathophysiologic changes and clinical pictures caused by cortisol excess, formerly Cushing's syndrome. (1) Adrenal tumor (adenoma/carcinoma) autonomously hypersecretes cortisol; ~25% of cases. (2) Pituitary adenoma or hypothalamic/CNS dysregulation causes excess ACTH → bilateral adrenal cortical hyperplasia with excess cortical hormones. (3) Ectopic ACTH from non-endocrine tumors (small-cell lung cancer), carcinoid (lung/GI), thymoma, pancreatic tumor, medullary thyroid carcinoma, ganglioneuroma, melanoma and prostate cancer → ectopic ACTH syndrome. (4) Iatrogenic: long-term high-dose glucocorticoid therapy; resolves after discontinuation. Aldosteronism: primary or secondary. Primary aldosteronism is rare, caused by adrenal cortical adenoma/hyperplasia hypersecreting aldosterone. Secondary is due to extra-adrenal disease causing excess aldosterone: nephrotic syndrome with edema, cirrhotic ascites, heart failure, and malignant hypertension. Here we discuss primary. Primary aldosteronism = aldosterone excess with suppressed renin, clinically characterized by hypertension and hypokalemia. Conn (1954) first reported cure after removing an aldosterone-secreting cortical adenoma → Conn's syndrome. Almost all causes are small benign adenomas in the outermost adrenal layer; adrenal carcinoma is very rare (~1% of low-renin aldosteronism); fewer than 50 cases reported internationally. Estimated prevalence 0.65%-2% among hypertensives. Adrenogenital syndrome: abnormal external genitalia/secondary sex characteristics due to congenital or acquired adrenal disease, also called adrenogenital syndrome. 1. Classification: rare; ~100 domestic cases; classified by age, sex, etiology and type of abnormal sex characteristics. 2. Etiology: hyperplasia mainly affects the reticular zone. Human adrenal produces mainly androgens, little estrogen. Normal cortical development requires normal enzymes; enzyme deficiency or dysfunction impairs cortisol synthesis and drives cortical hyperplasia, amplifying androgen effect — like pouring oil on fire, large amounts of androgens masculinize female patients. Tumor etiology is due to tumor-secreted and accumulated sex hormones. Pheochromocytoma: adrenal medulla lies in the middle, ~10% of adrenal volume. Medullary cells vary in shape; when treated with chromium-containing fixative, granules stain — hence chromaffin cells. Pheochromocytomas are mostly benign (~90%); size from loquat to hami-melon, usually orange-sized, flattened/round with slight fan shape, deep yellow/brown cut surface, lobulated; tumor cells irregular polygonal, variable size, multinucleate with many chromaffin granules; suspected malignant ones are darkly stained. Adrenal medulla: sympathetic nerve endings and CNS synthesize dopamine, norepinephrine and epinephrine from blood tyrosine — collectively catecholamines. After neural cells synthesize catecholamines they are transported to nerve endings for release. Medullary dopamine is an intermediate product; dopamine-β-hydroxylase converts it to norepinephrine then epinephrine, both released directly into blood. When chromaffin cells tumorize, large amounts of epinephrine/norepinephrine are stored in the tumor. Usually unnoticed, but on stimulation the tumor releases considerable catecholamines → sudden hypertension and arrhythmia; explosive stress can be fatal. Adrenal malignant tumor: Adrenocortical carcinoma is rare, usually functioning, larger than adenoma at discovery, often >100 g, infiltrative growth destroys/subsumes normal adrenal, invades surrounding fat and even the kidney. Small adenocarcinomas may be encapsulated; brown-yellow cut surface with common hemorrhage/necrosis/cystic change. Microscopically poorly differentiated with high atypia, variable cell size, bizarre nuclei and multinuclei, frequent mitoses. Often metastasizes to aortic nodes or hematogenously to lung/liver. Well-differentiated looks like adenoma microscopically; small encapsulated ones are hard to distinguish; some suggest tumors >3 cm favor well-differentiated adenocarcinoma.

Treatment

Drug therapy, surgery, supportive therapy

Preventive Measures

Women should pay attention to perinatal physiologic/psychologic health to ensure fetal healthy development, possibly preventing this lesion. In Western countries, consanguineous families have reported pheochromocytoma patients with relatives also having pheochromocytoma and multiple endocrine tumors secreting multiple hormones; such cases are increasing, with a few domestic reports. In 1993, Cancer Hospital of the Chinese Academy of Medical Sciences treated a 15-year-old Black male with right-adrenal pheochromocytoma plus thyroid tumor, cured after resuscitation and surgery.

Department to Visit

It is recommended to visit the Urology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.