Evaluation of a large adrenal carcinoma with 3D reconstruction of computed tomography images: A case report and literature review

1Introduction

With the development of imaging techniques such as ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI), the detection rates of adrenal masses has remarkably increased [1, 2]. Most adrenal masses are benign tumors, dividing into three types: adrenocortical adenomas or carcinoma within the adrenal cortex, neuroblastoma and pheochromocytomas within the adrenal medulla [3]. In malignant tumors of adrenal glands, adrenocortical carcinoma (ACC) is an exceedingly rare disease caused by a cancerous growth within the cortex. ACC has the estimated incidence of 0.7 cases per million per year in the United States and lead to 0.2% of all cancer deaths [4, 5]. ACC may occur in adults or children with a female to male ratio of 1.5 – 2.5:1 [5, 6]. Many ACCs are asympomatic and nonfunctional as adrenal incidentalomas. However, some ACCs may be “functional”, producing excessive adrenal hormones. This type of malignancy results in endocrine dysfunction by large amounts of cortisol, testosterone, and aldosterone. Because of their deep location in the retroperitoneum, most ACCs are not diagnosed until they grow to a large size. Frequently, ACCs can invade adjacent large vessels, the renal vein as well as the inferior vena cava. If an ACC is found to be functional, the tumor necessitates surgical removal, although chemotherapy, radiation therapy, and hormonal therapy may also be employed to treat ACC depending on various stage of carcinoma [1].

For surgical resection of adrenal benign mass, laparoscopic adrenalectomy is a common surgery regarded as a gold standard [7]. Compared with laparoscopic via abdominal approach, retroperitoneal laparoscope adrenalectomy is extensively operated for less invasiveness and easy postoperative care [8]. However, due to complicated anatomy and the limited space around adrenal glands, laparoscope adrenalectomy from retroperitoneal approach is a challenge for large tumors (>6 cm in diameter) because the tumors might affect the adjacent important organs or tissues such as kidney, liver or spleen, and inferior vena cava [9]. Thus, to achieve better outcome via retroperitoneal laparoscopy in the treatment of a large and deep-located adrenal tumor, it is required more detail information based on the x-ray images to precisely evaluate the size, location, adhesion with the adjacent tissue, blood supply and metastasis of ACC in anatomic before surgery.

In clinic routines, images in 2D patterns are often used to represent 3D tumor tissue in the body, which limits in illustration of the reality of tumor. Recent advances in medical imaging and radiological technology have meaningfully contributed to surgical development in diagnose, prognosis and treatment of disease [10–12]. Three-dimensional (3D) reconstruction image based of CT and MRI has provided more accurate and insight illustration for better evaluation in surgical planning [13]. The 3D reconstructed images provide more detail information about anatomic relationship and morphological features of diseased tissues or tumors [14–16].

In this study, we developed a technology to generate a video originated from 3D reconstructed CT images. The processed videos demonstrated dynamic, stereo and all-round information, which offered an easier and more accurate pattern to develop a surgery strategy, particularly for performing endoscopic or laparoscopic surgery. With the aid of this 3D video, we successfully removed a large (about 7-cm in diameter) ACC tumor by a laparoscopic resection via retroperitonealapproach.

2Case report

A 55-year-old male patient presented with decline in physical activity and frequent fatigue. On physical examination, his blood pressure was 169/106 mmHg. Laboratory investigations including catecholamines, aldosterone, cortisol, and potassium concentrations in blood or urine revealed 17-hydroxy corticosteroid significantly increased (82.54 μmol/24 h, normal arranging from 8.3 to 27.7 μmol/24 h). Abdominal ultrasound and CT scan indicated a large mass in the right adrenal area. Enhanced CT scan further determined the location (right adrenal), property (neoplastic lesion) and size (6.8 cm ×5.2 cm) of tumor. The CT images were reconstructed into 3D images as a regular pattern (Fig. 1). Further, we integrated all CT data into a 3D adrenal tumor model separated from kidneys, liver, spleen, spine ribs, inferior caval vein and artery by 16.0 Mimics software. The video clearly showed that the isolated tumor was originated from right adrenal gland, which separated from other organs (Fig. 2). After evaluating the surgery risk based on the anatomic relationship among adjacent organs, we made operation planning for retroperitoneal laparoscopic adrenalectomy according to the video. The huge adrenal gland was completely resected with no-injury to liver, right kidney, and other neighboring vessels and tissues (Fig. 3). The operative duration lasted 87-minute and the estimated blood loss was less than 150 ml. No intraoperative and postoperative complications occurred. The pathologic diagnosis was adrenal cortical carcinoma (Fig. 4). Six-month follow-up showed no significant complication associated with surgery.

3Discussion

To meet the requirement of high quality, safety, and time efficiency, modern CT technique provides a noninvasive approach to obtain a complete cross-sectional X-ray image of entire organs in human body. As laparoscopic surgeries are widely used, it is critical to obtain clear and detail image information about the size, number, location of the tumor lesion and the adhesion status between the tumor and the adjacent organs, vascular distribution and metastasis before surgery. Typically for adrenal surgery, the retroperitoneal space is limited for laparoscopic surgeries [13, 17, 18]. It is a challenge to resect large retroperitoneal neoplasms via retroperitoneal approach [17, 18] because it’s more likely to affect and damage adjacent organs and tissues. In this case, we successfully removed a large adrenal cancer tumor with the aid of dynamic 3D video.

ACC is an extreme rare carcinoma originated from adrenal gland cortex. It is difficult to identify whether the adrenal tumor is benign or malignant before pathological examination. Therefore, the best choice is to resect entire tumor to prevent recurrence and spread of cancer cells. With the aid of 3D reconstruction technology [13], tumor tissue could be precisely evaluated to help make appropriate surgery plan [10]. More applications of 3D reconstruction of CT data have been reported (Table 1) [19–24]. The 3D dynamic videos of target organs can be not only acted as an optimal diagnostic approach for surgery but also be as a better learning tool for residents or medicalstudents.

4Conclusions

The majority of adrenal gland neoplasm is benign, even the malignant neoplasm does not cause serious damage to the adjacent tissue or organs. Thus, the least invasive operation would be best choice for ACC tumor, which helps the wound recover sooner than open surgery. In aid of 3D dynamic video from reconstruction of CT data, laparoscope adrenalectomy is feasible via retroperitoneal approach to resect a large entire adrenal carcinoma.