CASE 14593 Published on 01.05.2017

Incidental detection of bilateral adrenal myelolipoma

Section

Uroradiology & genital male imaging

Case Type

Anatomy and Functional Imaging

Authors

Dr. Asma Jatoi, Dr. Sumaira Babar, Prof. Tariq Mahmood

Jinnah Postgraduate Medical Center;
Rafique shaheed road
75500 Karachi, Pakistan;
Email:drasmaj@hotmail.com
Patient

45 years, male

Categories
Area of Interest Adrenals ; Imaging Technique CT
Clinical History
A 45-year-old male patient presented to us with the complaint of mild bilateral flank pain and gastric burning for the past 4 months. He was on pain killers which were prescribed by his family physician. His physician advised him to undergo contrast-enhanced CT examination of the abdomen.
Imaging Findings
CT abdomen reveals incidental findings of fairly well-circumscribed encapsulated masses in the left and right supra-renal regions, containing predominantly fat and few soft tissue strands which show enhancement (Fig. 3). The mass on the left side measures 18.9 x 12.8 x 17.6 cm, causing infero-medial displacement of the left kidney and left renal vein in the pelvis (Fig. 1). Great vessels are displaced towards mid-line by the mass. The mass is pushing the body and tail of the pancreas anteriorly and the spleen laterally (Fig. 2). It is also displacing the adjacent bowel loops.
The mass on the right side is seen with similar properties. It measures 6.0 x 5.0 cm causing inferior displacement of the right kidney (Fig. 4).

On concomitant ultrasound abdomen, a hyperechoic mass is seen in the right and left supra-renal region with undefined margins (Fig. 5).
Discussion
DISCUSSION

Adrenal myelolipomas are rare benign, non-secretory and usually asymptomatic tumours of the adrenal gland characterized by a variable amount of fat-containing components. These tumours account for 3–5% of all primary tumours of the adrenals and are identified as incidentalomas. There is no gender predilection. Typically, they are over 4 cm in size. If they are more than 4 cm in size, they present with mass-related symptoms like pain. Larger myelolipomas are at risk of localized tissue death and bleeding, which may cause a retro-peritoneal haemorrhage. [4]

IMAGING FINDINGS

Plain radiograph is non-specific and not an imaging modality for these lesions.

Sonographic appearances vary with the composition of the neoplasm. If the tumour contains predominantly fatty components, it appears uniformly hyperechoic. If the tumour contains predominance myeloid cells, it appears heterogeneous or hypoechoic. The classic appearance is of an echogenic suprarenal mass.

The preferred imaging modality is computed tomography which predicts the presence of adrenal myelolipoma with 100% specificity. [1]
The typical adrenal myelolipoma appears as a fat-containing mass. The fatty component interspersed with higher-attenuation myeloid tissue is diagnostic. The attenuation values are low (-20 to -30 HU), reflecting the mixture of adipose and myeloid elements. The masses usually have a capsule and may contain calcification (20%). Calcification may be due to previous haemorrhage. After contrast administration, the mass shows enhancement.

On MRI
T1: Hyperintense due to fat content.
T2: Intermediate to hyperintense due to haematopoietic tissue
T1 (FS) sequence: Shows fat suppression of the mass, which further confirms the diagnosis.
T1 (GAD): Shows striking enhancement.

Differential diagnosis includes fat-containing adrenal carcinoma which is a malignant tumour containing areas of haemorrhage and necrosis with heterogeneous enhancement. Another differential would be of retroperitoneal liposarcoma which is malignant and appears hypertense on T2WI with delayed post-contrast enhancement.

TAKE HOME MASSAGE

Bilateral adrenal myelolipoma is a rare benign neoplasm and mostly discovered as an “incidentaloma”. Imaging findings and histopathological features of bilateral adrenal myelolipomas will facilitate timely diagnosis and treatment of this condition.

OUTCOME

As adrenal myelolipomas are benign lesions, they have no malignant potential. If imaging features are characteristic and the lesion is small, no treatment is required. But if they are large enough to produce mass-related symptoms, then they are surgically removed and after surgical resection, these lesions do not tend to recur. [1]
Differential Diagnosis List
Bilateral adrenal myelolipoma
Retroperitoneal liposarcoma
Fat-containing adrenocortical carcinoma
Final Diagnosis
Bilateral adrenal myelolipoma
Case information
URL: https://eurorad.org/case/14593
DOI: 10.1594/EURORAD/CASE.14593
ISSN: 1563-4086
License