A Rare Case of a Giant Adrenal Incidentaloma in 78 Year Old: Incidence, Radiologic and Management Issues of Adrenal Myelolipoma

Abstract

Adrenal myelolipoma is a rare benign neoplasm composed of mature adipose and hematopoietic tissue. Most lesions are small, unilateral and asymptomatic, discovered incidentally at autopsy or imaging studies performed for other reasons [1]. The incidence of Adrenal incidentalomas is at least 2% in the general population [2]. The prevalence of finding an adrenal myelolipoma from an incidentaloma is very small. In autopsy studies, the incidence of adrenal myelolipoma is reported as being 0.08 to 0.4% 1 with a male-to-female ratio of 1:1. No other documented case of Adrenal Myelolipoma was ever reported in our institution and only 1 published case of Adrenal Myelolipoma locally [3].The present case is a 78-year old Filipino man who on executive check-up had an incidental finding of adrenal mass. Biochemical evaluation revealed that this was a non-functioning adrenal mass. Further evaluation including MRI of the adrenal gland showed a right suprarenal mass lesion with enhancing solid and fat components consistent with Myelolipoma.Since population based studies have limited data regarding the epidemiology of Adrenal myelolipoma, we are reporting this case to help future research studies.Patient was completely asymptomatic except for an on and off vague right flank pain with no associated fever, unexplained weight loss, tremors, palpitations, or changes in urine. Vital signs were stable and normal. He was not pale and did not have acne, moon facies, buffalo hump, or anterior neck mass. He had regular a cardiac rhythm and the apex beat was not displaced. The abdomen was soft, with no palpable masses, tenderness or violaceous striae. He had no edema, tremors or ecchymosis, and had equal peripheral pulses.To determine the nature of the mass, biochemical evaluation was done which showed an AM cortisol of 9.91 μg/dl (7-25 μg/dL) and serum aldosterone of 10 μg/dl (<21 ng/dL). Other biochemical tests including catecholamines were normal and consistent with a nonfunctioning tumor.Further imaging with MRI of the adrenal glands with contrast revealed a multilobulated mass lesion in the right suprarenal region insinuated between the medial margins of the right lobe of the liver and medial crus of the left hemidiaphragm, measuring about 4.3 × 3.6 × 7.2 cm (AP × T × Cc). (Figure 1) The lesion appeared to be heterogeneous most prominently of signals completely suppressing on the fat saturation sequences, findings consistent with adrenal myelolipoma.Due to the large size of the tumor and the risk of retroperitoneal bleeding, the patient agreed to an Elective Laparoscopic Adrenalectomy