The incidentaloma was unilateral in 35 cases and bilateral in one. Clinical data of 36 incidentaloma patients is presented in Table 3. The size of the lesions was mean 3.9 cm (range 1 to 16 cm). A total of 19 cortical adenomas were discovered. Six patients had multiple nodules (nodular hyperplasia), one of them bilaterally. Four pheochromocytomas without signs of malignancy were diagnosed. Two patients had ganglioneurinomas, two had organized hematoma, one intraadrenal lipoma, one myelolipoma, and one a calcified cyst. The cortical adenomas ranged in size from 1 to 16 cm (mean 3.5 cm). Only 2 of these 19 adenomas were 5 cm or larger, whereas 10 of the 17 other incidentalomas were 5 cm or more in size.
Table 3. Clinical data of 36 incidentaloma patients.
Hormonal evaluation had been done in 30 patients, and 7 incidentalomas were hormonally active. Elevated values of cortisol production were found in two patients; each had a cortical adenoma, 2 cm and 4 cm in size. One patient had elevated androgen values related to a histologically benign adenoma, 16 cm in diameter. The VMA and metanephrines were elevated in three patients, and marginally elevated in one patient. Hormonal evaluation had not been done in one of the pheochromocytoma patients. A 4-cm mass found in the region of the left adrenal gland near the tail of the pancreas was falsely interpreted as a pancreatic tumor. No a-blockade was used, but the surgery was uneventful. The patient with marginally elevated values did not have a pheochromocytoma; he had macronodular cortical hyperplasia without other hormonal changes. In further five patients the hormonal evaluation had not been done, because the patients were operated on for another disease, and the incidentalomas were not thought to have any clinical significance.
Iodonorcholesterol scintigraphy had been carried out to detect possible cortical hyperfunction in 6 patients; all showed uptake (one bilaterally). Only one of these patients had hypercortisolism; she had a cortical adenoma. The patient with bilateral uptake had bilateral nodular hyperplasia, the other patients had unilateral nodular hyperplasia or cortical adenomas. Selenonorcholesterol scintigraphy was carried out and it was negative in one patient.
MIBG scintigraphy had been carried out on three hypertensive patients; all were negative, and none of these patients had a pheochromocytoma.
One patient having a pancreatic carcinoma and an adrenal mass died of bleeding after pancreaticoduodenectomy, but operative mortality related to adrenalectomy was 0%. One patient had splenectomy done, because of an intraoperative lesion of the spleen. Two patients had postoperative wound infection. One patient was slightly hypotensive during the first postoperative day for an unknown reason, but he recovered spontaneously and had no further complications.
Twenty-seven patients had an incidentally discovered adrenal mass, 3 a bilateral incidentaloma. The mean size of the incidentalomas was 2.5 cm, (range 1.5-4 cm), eight were 3 cm or larger. Hormonal evaluation had been negative in all cases. The mean follow-up time was 85 months (range 23-196 months).
Nine patients had died before this follow-up program started. The mean age at death was 73 years. The cause of death was acute myocardial infarct in 3 cases, ventricular arrhythmia after aortic and mitral valve reconstruction, pulmonary oedema caused by cardiac failure, thrombosis of femoral vein and pulmonary embolism, acute cerebrovascular infarct, bolus suffocation related to multi-infarction dementia, and lung carcinoma with cerebral metastases. In death certificates and available medical records nothing suggested that these deaths would be related to the incidentalomas. An autopsy had been carried out on 4 patients. In 3 cases the incidentaloma had been documented: 2 cortical adenomas and one myelolipoma were found. No change in the size of the incidentalomas could be noticed.
Sixteen patients attended the follow-up program. None of the patients had any symptoms related to the incidentaloma. Two patients did not want to be re-examined, but stated that they were asymptomatic. The results of the hormonal tests were normal. MRI could not find any adrenal pathology in 4 patients, although the visualization of the adrenal glands was considered excellent. In one of these cases the incidentaloma had cystic appearance and had been emptied with aspiration. One adrenal gland was horizontally positioned and this had caused the misinterpretation of adrenal tumor in the original CT examinations. In 2 cases the incidentalomas had diminished in size already during the original one-year follow-up and had been considered adrenal hematomas. The sizes of 7 incidentalomas had not changed. 5 incidentalomas were larger and 3 incidentalomas were smaller than at the time of detection. The change was from 4 to 10 mm.
When compared with the MR signal of normal adrenal tissue, the T1 and T2 signals of the observed tumors were isointense in all except one case. This particular tumor appeared homogeneously hyper intense in T2 weighted images. The lesion showed no contrast enhancement. Such a tumor correlates well with a simple cyst. All the other adrenal tumors demonstrated a minor rim enhancement of the lesion 25 sec after the contrast injection. The following slices, 55 sec after the injection, showed a slight and equalized enhancement of the tumor analogous to the surrounding normal adrenal tissue.
All 29 operated patients were hypertensive, and all but one had a low serum potassium level. The mean serum potassium was 2.9 mmol/L (range 2.2-3.6). The hypertension was generally not in good control. The mean duration of hypertension at the time of the operation was 105 months (range 1-360). The finding that primarily had led to the suspicion of primary aldosteronism was poorly controlled hypertension with low serum potassium in most cases.
The postural test during volume load could be reliably interpreted in 18 cases. There was a clear decline in plasma aldosterone level, suggesting adenoma, from 8 a.m./recumbent to 12 p.m./supine in 16 cases. 15 of these cases were adenomas, and one was an adenoma with micronodular hyperplasia. The result was inconclusive in one patient having an adenoma, and the plasma aldosterone level increased, suggesting hyperplasia, in one patient having an adenoma.
The CT scan was carried out and had correctly localized the adenoma in every case. Twenty-five patients had a unilateral solitary adenoma with otherwise normal adrenal histology. The mean size of the adenomas was 15 mm (range 8-32). Fourteen adenomas were on the left side, and eleven on the right. One patient had an aldosterone producing cortical carcinoma, 11 cm in diameter, with no lymph node involvement or distant metastases. One patient had macronodular hyperplasia. The largest nodule, 10 mm in size, was seen in CT; the contralateral gland was normal in CT and in laparotomy. Two patients had an encapsulated adenoma, 15 and 25 mm in diameter, but also micronodular hyperplasia. In one of these cases a hormonal analysis of cultured adrenal cells had been carried out, and only the adenoma cells were found to produce aldosterone. The cells of micronodular hyperplasia were inactive.
There was no mortality, or major operative or postoperative complications. The serum potassium level was normalized in all patients during the first postoperative week. The mean blood pressure levels at the time of discharge were significantly lower than preoperatively, 140/90 and 183/113 mmHg, respectively (p>0.001). Only three patients had a diastolic blood pressure over 100 mmHg, although the effect could be partly due to perioperative antihypertensive treatment.
One patient had died during the follow-up period, 21 months postoperatively, owing to cholangiocarcinoma with distant metastases. The patient operated on for the adrenocortical carcinoma had mild medicated hypertension and no signs of recidivist disease at the end of the follow-up study. However, pulmonary metastases occurred later and the patient died 74 months postoperatively. The mean follow-up time for the living patients with benign disease was 76 months (range 9-154), and the effect of the operation on hypertension was estimated by the patient and her or his doctor at the end of the follow-up. The hypertension was cured in 11 cases (41%). In 10 cases (37%) the hypertension after the operation was mild and responded well to medication. In the remaining 6 cases (22%) the blood pressure values did not respond to the operation, although the hypertension is better controlled by the medication. The duration of preoperative hypertension did predict the outcome of surgery.
In two patients with solitary adenomas the serum potassium level dropped below normal during the follow-up, but no signs of persistent hyperaldosteronism could be found.
The duration of narcotic analgesia was in average 1.7 days (range 1-4 days). The mean decrease in hemoglobin value was 12.2 g/L (range -3 - 41 g/L). The average length of hospital stay was 3.4 days (range 2 - 5 days) and the length of sick leave was on average 13.2 days (range 8 - 18 days). All patients became normokalemic after the operation. Two patients had postoperative complications, both having pain at the trocar wound region. They were treated with non-steroid anti-inflammatory drugs and the pain resolved within 2 weeks postoperatively. On follow-up (mean 12.5 months, range 2-28 months) 4 patients were normotensive without medication, 8 patients were on antihypertensive drugs, but in all cases the medication had been reduced from the preoperative level.
The indications for the operation were suspected aldosterone producing adenoma (20), pheochromocytoma (9), Cushing's adenoma (3), Cushing's disease (1), adrenocortical hyperplasia with hypercortisolism caused by ectopic ACTH production (1) and incidentally discovered hormonally inactive adrenal tumor (4). Two of the Conn's adenomas had been detected as incidentalomas. One of the suspected Cushing's adenomas turned out to be a low-grade cortical carcinoma. One suspected pheochromocytoma turned out to be a hematoma. The four hormonally inactive incidentalomas were: 1 hematoma, 1 cyst, 1 inactive cortical hyperplasia, and 1 inactive cortical adenoma.
The mean size of the tumors was 2.6 cm (range 0.8-8 cm). Sixteen lesions were on the right side, 24 on the left side; in two patients both adrenals were removed. The mean weight of the patients was 81 kg (range 27-121 kg) and the BMI was on average 28 kg/m2 (range 17-31 kg/m2).
The mean operating time was 121 minutes (range 53-360 min.). The operating time was significantly longer in male patients than in female patients, 156 min. and 105 min., respectively (p<0.001). The mean BMI of male patients was 29.5 and of female patients 26.5. The difference is not statistically significant. The mean operating time for patients with BMI >30 (n=12) was 126 minutes and for patients with BMI <30 120 minutes. The mean operating time for tumors 4cm in size or more was 132 min (n=10) and for tumors less than 4cm in size 118 min. The mean operating time for left-sided tumors was 125 min and for right-sided tumors 116 min The size of the tumor, BMI, or side of the tumor did not have significant effect on the operative time. The mean operating time for the last 20 operations (112 min) was shorter than for the first 20 operations (131 min), but the difference was not significant. The estimated intraoperative bleeding was on average 80 mL (range 0-800 mL).
Four of the eight pheochromocytoma patients had transient elevations in blood pressure during the procedure, but they were easily controlled with medication. There was no marked hypotension during the operation or postoperatively.
Usually the adrenal gland could be dissected free without damage to the adrenal tissue. Sometimes small tears of the border of the normal adrenal tissue were noticed. The tumor itself was never grasped and every gland could be resected and positioned in to the plastic bag without damage to the tumor tissue.
Conversion to laparotomy was done in one case (2.4%). This obese woman (BMI 35 kg/m2) had hypercortisolism and bilateral adrenocortical hyperplasia caused by ectopic ACTH syndrome. She had undergone right hemicolectomy for a colon carcinoma. After the left adrenal had been successfully removed laparoscopically, an attempt to perform laparoscopic procedure on the right side was done in spite of an extremely enlarged liver and postoperative adhesions. It turned out to be technically impossible and the operation was converted to laparotomy through a subcostal incision.
The median postoperative hospital stay was 3 days (mean 3.6 days, range 2-12 days). All patients were able to start oral intake during the first postoperative day. The patients needed narcotic analgesics on average 1.8 days (range 0-8 days) postoperatively. The median postoperative sick leave was 17 days (mean 21.2 days, range 8-55 days).
There was no mortality nor reoperations. Seven patients had postoperative complications (18 %). One patient had transient postoperative dyspnea. A small pulmonary embolus was found in a CT scan and was treated with anticoagulation. This patient was the one converted to laparotomy and therefore had the longest operative time in the series. The patient was also extremely obese. One patient developed a pneumothorax treated with pleural suction for 4 days. Two postoperative bleedings at the operative site required red blood cell transfusions. Two patients had prolonged pain at a trocar wound. One patient had a urinary tract infection, and was treated with antibiotics.
The duration of follow-up was on average 5 months (range 1-28 months). All patients were considered to have responded as expected to the adrenalectomy, and no evidence of a recurrent tumor or any symptoms of hormonal activity were observed.
After the first eight laparoscopic operations had been successfully done, we decided to operate all small benign adrenal tumors laparoscopically. After this point, 9 patients were treated by conventional open adrenalectomy at our hospital. Data on conventional open operations performed was collected, but it was not possible to compare these two different groups of patients.