This case was interesting from many sides. Firstly, the combination of ESP block with the mini-invasive approach allowed to reduce postoperative pain with a complete patient’s satisfaction. Secondly, the role of multidisciplinary team favored the correct timing, the correct indication and the correct approach to this pathology.

The ESP block is an interfascial block which allows for the dispersion of the local anesthetic in the interfascial plane between the process transversus and erector spinae muscles. This block achieves a paravertebral spread of three and four vertebral levels cranially and caudally, respectively, covering the ventral and dorsal rami of spinal cord thus inhibiting both visceral pain than the somatic one.

Ultrasound guided ESP block may be considered as an alternative technique to epidural anesthesia because it provides an effective postoperative analgesic coverage for breast and thoracic surgery when performed at T4-T5 level or for abdominal surgery at T7-T8 level [4]. Althought, epidural anesthesia generally considered a safe technique, it is not free of possible complications:  epidural hematoma and postoperative neurologic deficit are rare, but post dural puncture headache is not. Moreover, introduction of enhanced recovery after surgery (ERAS) protocols and a shift from open to laparoscopic surgery have diminished the advantage of epidural anesthesia. In a recent review on this topic, the authors suggested that epidural anesthesia in abdominal surgery has become less preferred and limited to surgical procedures with difficult pain management [16].

In this case we wanted to assess the effectiveness of the ESP block on postoperative pain, with the purpose also of limiting opioid administration and then possibly reducing postoperative nausea and vomiting. We also wanted to observe the response of the patient in terms of satisfaction and postoperative recovery. No analgesics were required in the first 48 hours after surgery, except for 1 g of Paracetamol in 2^nd post-operative day. Recovery was fast and the patient was discharged satisfied after three days. ESP block is currently used in various types of abdominal surgery (cholecystectomy, ventral hernioplasty, hysterectomy, nephrectomy) but as regards adrenalectomy no studies were found [1- 9].

Laparoscopic andrenalectomy (LA) has rapidly become the gold standard in management of adrenal tumors, especially for better outcomes in terms of cosmesis, hospital stay, less operative time and blood loss and rapid activity restoration [1]. Despite that, the mass dimension can be a relative contraindication for the mini-invasive approach, especially due to the malignant potential and the risk of intraoperative rupture. Moreover, the dimensional cut off is the main subject of discussion [2].

We decided to approach this case with a mini-invasive approach due to our center expertise in laparoscopic surgery, because at the preoperative CT scan the mass was less than 10 cm with no clear signs of malignancy, and because we are extremely clear with patient explaining that we will have converted in any case of intraoperative need. In any case, the intraoperative findings were comforting because we didn't find any neighboring organs invasions and no difficulties in mass detachment, as also no mass rupture. Moreover, to avoid sealing, the mass was carefully removed with an endobag from the Pfannestiel incision.

Literature reported cases successfully performed in laparoscopy also for non-functional mass near to 18 cm [1,2]. However, the center expertise in minimally invasive surgery should always be considered [2]. In case of local invasion or vascular infiltration open approach is more suitable and indicated [2].

Some studies compared different mini-invasive approaches: the laparoscopic or retroperitoneal adrenalectomy [10]. In a recent systematic review comparing these two techniques, no differences were found in terms of blood loss, hospitalization, pain score, operative time, complications, and return to normal activity. However, the lack of high-quality data in literature makes still difficult to make definitive conclusions [11]. The surgeon expertise and comfort in one technique should rather guide the choice.

The pre-operative and intra-operative findings deposed for a non-functioning and probably benign mass; however, the definitive confirmation came only with the result of the histological examination.

In our case, the final histopathological result of the adrenal mass deposed for a benign ganglioneuromas. Ganglioneuromas (GN) account for less than 5% of adrenal masses, with a slight female prevalence, and occurs more frequently in children and young adults [12]. However, some recent studies have shown they may also be found over 40 years old [13]. GN originates from the autonomous sympathetic nervous system, either central or peripheral, and presents the least aggressive profile among the neural crest‑derived tumor, so the prognosis is excellent after surgical resection, in contrast to other less differentiated neuroblastic tumors (ganglioneuroblastoma and neuroblastoma) [12]. GNs are detected mostly by accident, being usually asymptomatic and endocrinologically inactive; however, they can grow and become large enough to cause symptoms due to mass effect. Hormone hypersecretion is infrequent: cathecholamines in a minority of cases, rarely dopamine [14]. It remains difficult to discriminate a GN from other adrenal masses according to radiological features, thus histology has a central role.

Adrenal masses presenting characteristics of malignancy should undergo PET scan because that may help to differentiate malignant from benign lesions with 100% sensitivity and 98% specificity [15]. Our patient underwent to a 18FDG PET/TC, presenting a large adrenal lesion, coupled with two indefinite liver nodules.