Effectiveness of Robot-assisted Adrenalectomy for a Giant Adrenal Hemangioma: A Case Report

Abstract

Background

Adrenal hemangiomas are extremely rare benign tumors that often need to be distinguished from malignancies. Adrenal tumors >4 cm in size are treated surgically because the possibility of malignancy cannot be ruled out. Traditionally, open surgery has been the mainstay of treatment; however, in recent years, robot-assisted surgery has been increasingly used for tumors of larger size and suspected malignancy. Here, we report a case of robot-assisted adrenalectomy for an 11 cm adrenal hemangioma.

Case Report

A 62-year-old male with lateral abdominal pain was referred to our hospital for further examination and treatment. His medical history was significant for hypertension, diabetes, and dyslipidemia. Computed tomography revealed an 11 cm left adrenal tumor, and all endocrinological screening tests were negative. Because the possibility of malignancy could not be ruled out, a robot-assisted adrenalectomy was performed. The operation time was 129 min, and the estimated blood loss was 7 ml. Pathological findings revealed an adrenal hemangioma. The postoperative course was uneventful, and patient’s condition subsequently improved postoperatively.

Conclusion

Robot-assisted adrenalectomy was performed for a giant adrenal hemangioma without any complications. Robotic surgery is useful for resecting adrenal hemangiomas even exceeding 11 cm in diameter.

Adrenal hemangiomas are extremely rare, non-endocrine, benign tumors that must be differentiated from malignant tumors. Generally, surgical treatment is recommended for adrenal tumors more than 4 cm in diameter because the possibility of malignancy cannot be ruled out (1). In recent years, there has been a shift from open surgery to less invasive surgery. The introduction of robotic surgery may bring various advantages, such as shorter operation time, fewer intraoperative complications, and shorter hospital stay (2). However, the indications of robotic surgery for suspected malignancy or large tumors remain controversial. Herein, we describe the case of a patient with a giant 11-cm adrenal tumor, which was safely treated via robot-assisted adrenalectomy.

Case Report

A 62-year-old Japanese male with a left adrenal tumor was referred to our hospital for further examination and treatment. His medical history was significant for hypertension, diabetes, and dyslipidemia. Laboratory examination revealed no abnormalities in blood count or biochemistry. Urinary metanephrine, dehydroepi-androsterone, blood aldosterone, adrenocorticotropic hormone, and cortisol levels were within normal ranges, and the corticotropin-releasing hormone loading regimen was negative. Contrast-enhanced computed tomography (CT) revealed an 11 cm tumor in the left adrenal with internal heterogeneity, calcification, and fat concentration (Figure 1A and B). Magnetic resonance imaging (MRI) revealed a heterogeneous signal on T2-weighted imaging (T2WI) and reduced diffusion at the tumor margins (Figure 2). Based on imaging findings, the differential diagnoses were adrenocortical carcinoma, schwannoma, and sarcoma. Therefore, we performed robot-assisted left adrenalectomy via a transperitoneal approach using the da Vinci Xi system. The port placement is shown in Figure 3. Although the tumor was large, adhesion to the surrounding tissues was minimal and the surgery could be performed as usual. Operative time, console time, and estimated blood loss were 129 min, 81 min, and 7 ml, respectively. The surgical specimen measured 114×97×82 mm in size, and the macroscopic findings showed that the tumor was surrounded by a capsule with yellow and red areas mixed on the split surface (Figure 4A). Histologically, the tumor was composed of dilated vessels lined by nonatypical endothelium. These vessels contained fibrin thrombi and were accompanied by hemosiderin-laden macrophages. Adrenal parenchyma was not contained in the tumor (Figure 4B). Immunohistochemically, endothelial lining was positive for CD31 (Figure 4C) and negative for chromogranin A, synaptophysin, and p53. The Ki-67 index was <5%. Based on these findings, the tumor was diagnosed as an adrenal hemangioma. The patient was discharged on postoperative day three without complications. The patient has been under outpatient observation since discharge and has not experienced any recurrence.

Figure 1. Computed tomography imaging findings. Unenhanced computed tomography (A). Enhanced computed tomography scan, horizontal section, early phase (B).

Figure 2. Magnetic resonance imaging findings. T2 weighted image.

Figure 3. Port placement of robot-assisted adrenalectomy. 1. Fenestrated bipolar forceps; 2. Camera port; 3. Monopolar curved scissors; 4. Prograsp forceps; 5. Assistant port.

Figure 4. Histopathological features of adrenal hemangioma. Macroscopic findings (A). Hematoxylin and eosin staining (B). CD31(C).

Discussion

We experienced a case of a giant adrenal tumor, which was suspected to be an adrenal carcinoma and was treated safely with robot-assisted adrenalectomy. Pathological examination revealed that the tumor was hemangioma.

Adrenal hemangiomas are benign tumors arising from endothelial cells lining blood vessels. However, they are often difficult to distinguish from malignant tumors (1,2). The age of onset is usually 50-70 years, with a male-to-female ratio of 2:1. Although adrenal hemangiomas are usually asymptomatic and are incidentally detected on imaging, large or ruptured adrenal hemangiomas may cause unilateral abdominal pain (3). In our case, an 11-cm adrenal tumor was found on computed tomography (CT) performed for evaluation of left-sided abdominal pain. Adrenal hemangiomas have been reported to present with characteristic features. CT scans of adrenal tumors typically reveal a characteristic irregular peripheral enhancement with progression to the center of the tumor and calcification within the tumor, appearing as a speckled pattern throughout the entire mass (4). In our case, CT showed an uneven distribution and calcification of the tumor. However, 30% of adrenal carcinomas present with calcifications on CT and require differentiation (5). Surgical resection is recommended for adrenal tumors >4 cm in size due to the possibility of spontaneous rupture and malignancy (6). Therefore, we performed a robot-assisted adrenalectomy. The surgical approaches include open surgery, laparoscopy, and robotic surgery. Although open surgery was previously performed in cases of large adrenal tumors or suspected malignancy to avoid tumor rupture or dissemination, Zografos et al. reported that outcomes following laparoscopic surgery did not significantly differ from those following open surgery regarding perioperative complications. Moreover, laparoscopic surgery was associated with a shorter length of hospital stays, less intraoperative blood loss, and less postoperative pain than open surgery (7). Davey et al. also reported that laparoscopic surgery has a lower postoperative complication rate than open surgery (8). Additionally, Jalabneh et al. recommended laparoscopic surgery regardless of malignancy or tumor size (9). In contrast, Germain et al. reported that the laparoscopic approach for giant or suspected malignant adrenal tumors is contraindicated in situations where the risk of tumor rupture or incomplete tumor resection is high, and they described the upper limit of tumor size as 8 cm. Currently, there is no established method to diagnose adrenal hemangiomas before surgery, and a definitive diagnosis is made based on postoperative pathological findings. Therefore, the ability to safely perform minimally invasive surgery for giant adrenal tumors is currently under investigation.

Recently, robotic surgery for giant adrenal tumors has been performed in only a few cases. Agcaoglu et al. reported that for adrenal tumors >5 cm, robotic surgery requires less time and has a lower conversion rate to open surgery than laparoscopy (10). A prospective study comparing perioperative outcomes in 50 patients who underwent robotic adrenalectomy and 59 patients who underwent laparoscopic surgery found that robotic surgery had less impact on operative time when the tumor size was greater than 5.5 cm (11). Changwei et al. reported less intraoperative blood loss and shorter hospital stay with robotic surgery than with laparoscopic surgery (12). Lijian et al. reported that robotic surgery has been reported to be useful for obese patients and for adrenal tumors larger than 5 cm (13). Some studies have also reported that bleeding from the tumor, paranephric arteriovenous hemorrhage, and adhesions to the surrounding area are the main reasons for conversion from laparoscopic surgery to open surgery and that these factors can be improved by the 3-D vision of the robot (10,14). Ragavan et al. reported that robotic surgery for larger tumors has a lower risk of adrenal tumor rupture than laparoscopic surgery because there are fewer restrictions on motion (15). In contrast, Francis et al. reported that postoperative morbidity and mortality rates were similar between the laparoscopic and robotic approaches (16). Another drawback of robotic surgery is its high cost. Brunaud et al. reported that the cost of robotic surgery was 2.3 times more than that of laparoscopic surgery in their center. Based on these findings, robotic surgery may be useful for adrenal tumors, especially large tumors. A PubMed search revealed eight cases of giant adrenal tumors measuring >8 cm that were treated with robot-assisted surgery (Table I) (17-23). The patients’ age ranged between 16-73 years and included six males. Tumor size ranged from 8.3 to 16 cm in diameter. The patient in case 4 underwent robot-assisted partial adrenalectomy because the adrenal tumor exhibited characteristics of a benign tumor on preoperative imaging (20). All patients except the patient in case 4 underwent robot-assisted adrenalectomy because malignancy could not be ruled out by preoperative findings. All cases were performed with no perioperative complications. Adrenal carcinoma was diagnosed in two of the eight cases, and our case was the first case of an adrenal hemangioma measuring >8 cm in size treated with robotic surgery with no complications. Although the preoperative diagnosis of adrenal hemangioma is difficult and the risk of intraoperative rupture is higher than that of other adrenal tumors (24), robot-assisted adrenalectomy can be safely performed.

Table I. Previous case reports of adrenal tumors larger than 8 cm treated with robotic surgery.

EBL: Estimated blood loss; OT: operating time; M: male; F: female.

Conclusion

We safely performed robot-assisted adrenalectomy for a giant adrenal hemangioma. Robotic surgery may be useful, especially when malignancy is suspected, or the tumor is large.

Conflicts of Interest

All Authors declare that they have no conflicts of interest concerning this study.

Authors’ Contributions

NK wrote the manuscript and provided figures and tables. YK contributed to the study design. NK, YK, YK, HF, KY, JI, HI, and TT cared for the patients and administered the systemic therapy. ST and YN pathologically diagnosed the tumor as an adrenal hemangioma. All the Authors have read and approved the final manuscript.