Experience of a Tertiary-Level Urology Center in Clinical Urological Events of Rare and Very Rare Incidence. V. Urological Tumors: 1. Adrenal Myelolipoma

Abstract

Objectives: To present our center's experience in the management of adrenal myelolipoma in the context of shifting from the open to the laparoscopic adrenalectomy approach.

Materials and methods: A retrospective search of our center's records was done for reported cases of adrenal myelolipoma during the period July 2001-June 2016. All the cases with histopathologically-documented adrenal myelolipoma diagnosis were included. Relevant demographic and clinical variables were studied with a comparison between the open and laparoscopic approaches.

Results: Of more than 82,000 urological surgeries, 238 adrenalectomies were done with only 22 cases of myelolipoma that had a mean age and body mass index of 52.4 ± 10.3 years and 30.23 kg/m², respectively. The main clinical presentation was accidental discovery. The largest dimension of tumors varied from 6 to 16 cm. Computed tomography described a characteristic picture of hypodense heterogeneous adrenal tumors in all cases, while magnetic resonance imaging was indicated for malignancy suspicion in only 5 cases. Adrenal tumor markers were normal in all cases. Open and transperitoneal laparoscopic adrenalectomies were used in 14 and 8 cases, respectively. The latter approach was insignificantly advantageous in the need for blood transfusion, postoperative pain degree, need for analgesia, and hospital stay duration (p = 0.22). Histo-pathological examination revealed benign adipose tissue and myeloid cells and confirmed the diagnosis of adrenal myelolipoma in all cases.

Conclusions: Adrenal myelolipoma is a rare non-functioning benign tumor. Laparoscopic excision seems to be a promising alternative approach to the traditional open adrenalectomy, even in the context of large tumors and obesity.

Keywords: Adrenal gland; Adrenal myelolipoma; Incidentaloma; Laparoscopic adrenalectomy; Open adrenalectomy.

Fig. 1

Abdominal CT (axial cut): Large right adrenal mass with more or less heterogeneous low-attenuated or hypodense appearance and well-demarcated borders from the surroundings.

Fig. 2

Intraoperative laparoscopic anatomy of a giant right adrenal myelolipoma and surrounding structures (A). Demanding dissection of the mass at the sub-hepatic area (B) and from the IVC (C), and the giant size of the mass before retrieval (D) can be noted.

Fig. 3

Microscopic (histopathological) picture of adrenal myelolipoma. A, B Sections of the adrenal myelolipoma showing the two main components of the tumor, mature adipose tissue and myeloid cells (× 400); C, D Higher magnification power shows fat cells and all three lineages of hematopoietic marrow including megakaryocytes (× 1,000).