(1.01) Unexpected Hyperfunctioning Adrenal myelolipoma: a rare cause of mild autonomous cortisol secretion

Adrenal myelolipomas are uncommon benign tumors, composed of mature adipose tissue and haematopoietic elements. The majority are found incidentally and comprise 3.3–3.6% of all adrenal tumors. Usually asymptomatic, non-functioning but there have been a few reports of myelolipomatous masses associated with autonomous cortisol secretion in less than 3%. Hereby,we describe the case of a patient presented with an incidental adrenal myelolipoma with mild autonomous cortisol secretion (MACS).


Case(s) Description :

A 70-year-old male with past medical history of arterial hypertension, diabetes mellitus type 2, congestive heart failure and chronic obstructive pulmonary disease referred for evaluation due to incidental adrenal mass found on abdominal CT scan. On initial evaluation, he was asymptomatic and had not noticed changes in his physical appearance. On physical examination patient without discriminatory features suggestive of hypercortisolism state as dorsocervical fat pad, proximal muscle weakness, moon facies, abdominal striae or facial and abdominal hirsutism. Abdominal CT scan with adrenal protocol showed left unilateral adrenal lesion of 5.5 x 4.1 x 4.6 cm well circumscribed, composed of soft tissue with density intermixed an areas of fat attenuation and peripheral calcifications consistent with adrenal myelolipoma. In order to rule out a functioning incidentaloma, hormonal evaluation showed morning cortisol level after low dose 1mg dexamethasone suppression test elevated: 2.1 ug/dl. After that  a 8mg dexamethasone suppression test was done with elevated cortisol  of 3.19 ug/dl. Low-normal ACTH level of less than 5 g/ml which confirms ACTH-independent hypercortisolism and DHEA level of 34 ug/dl within the normal range as expected on this etiology. Considering the risk of metabolic complications and mass overgrowth; unilateral left-sided adrenalectomy demonstrate as the best treatment approach. Patient with multiple comorbidities needs preoperative evaluation before decide final treatment; left laparoscopic adrenalectomy vs medical therapy for MACS. Despite limited data regarding adrenal myelolipomas with MACS, evidence suggest unilateral adrenalectomy it appears to convey clinical and biochemical benefits in most cases.


Discussion :

Adrenal myelolipomas have been found to cause hypersecretory syndromes themselves in some cases as in our patient. Our case is an excellent example of the importance of individualizing management options based on therapy benefits. It also emphasizes the importance of screening for hypercortisolism in the presence of comorbidities associated with cortisol overproduction, even when the prevalence of hormone hypersecretion in myelolipomas is rare.