A 61-year-old white woman presented to the Urology clinic with left flank pain and a questionable history of weight loss. She has a medical history of nephrolithiasis and hypertension.
Chandana Lall, MD
Dr. Girish Agrawal, MD
from the Department of Radiology, and
Marjorie Fowler, MD
from the Department of Pathology at Louisiana State University
Health Sciences Center, Shreveport, LA.
A 61-year-old white woman presented to the Urology clinic with
left flank pain and a questionable history of weight loss. She has
a medical history of nephrolithiasis and hypertension. Past
surgeries included a cholecystectomy and hysterectomy. The patient
has a history of long-term tobacco use. Urinanalysis on admission
revealed microscopic hematuria. Hematologic workup was
Adrenal cortical adenoma with very atypical imaging features
The initial radiologic examination, an abdominal X-ray of the
kidney, ureter, and bladder (KUB), showed multiple amorphous
calcifications in the left mid-flank region, possibly within an
adrenal or upper renal pole mass (Figure 1). A follow-up
intravenous urogram demonstrated inferior dis-placement of the left
kidney with prominent areas of calcification superior to the left
kidney. A renal ultrasound showed a heterogeneous echo-texture mass
lesion in the expected location of the left adrenal gland, which
appeared separate from a normal-sized left kidney (Figure 2). A
noncontrast computed tomographic (CT) scan showed a heterogeneous
attenuation 11-cm mass with large amorphous calcifications as well
as islands of macroscopic fat, in the expected location of the left
adrenal gland (Figure 3A). Contrast-enhanced CT showed minimal
peripheral enhancement as well as prominent necrotic areas and a
few thin enhancing septations (not shown). Sagittal CT
reconstructions further substantiate the above findings (Figure
Grossly, the tumor mass measured 11 * 11 * 8 cm and weighed 480
g. It was adjacent to the kidney, but separated from it by
fibrofatty tissue. On the cut surface, the tumor was yellow to gray
and mostly smooth. There were large areas of hemorrhage and focal
areas that appeared to be necrotic or degenerative. Scattered 0.5-
to 1-cm cysts containing blood or necrotic debris were also
present. On cutting, bony hard areas could be appreciated.
Microscopically, the tumor mass contained uniform lipid-laden
adrenal cortical cells. Most of the central part of the lesion was
hemorrhagic with large areas of hyaline and myxoid degeneration.
There were large bands of fibrous tissue traversing the areas of
degeneration. Focal areas of fatty metaplasia and osseous
metaplasia were present (Figure 4).
Characterization of adrenal masses is an important clinical
problem and a focus of abdominal imaging research, because adrenal
masses are frequently seen as the so-called incidentaloma. They
appear in autopsy series with a reported prevalence of 2% to 9%.
Although most incidentally discovered adrenal masses represent
benign cortical adenomas, often imaging features cannot reliably
differentiate an adenoma from more ominous lesions.
On imaging, an adrenal adenoma is typically a small (usually
<5 cm), well-circumscribed, homogeneous mass with near fluid
attenuation values on precontrast CT and uniform contrast
enhancement with rapid washout of iodinated or gadolinium-based
contrast material. Adenomas frequently demonstrate the presence of
intracellular lipid and almost never liquefy. Calcification is
rare. They may occasionally undergo intratumoral hemorrhagic
degeneration with the development of cystic internal spaces and
The imaging findings in this case were not characteristic of a
benign cortical adenoma. There were large areas of osseous
metaplasia as well as scattered areas of necrosis. Additionally,
prominent islands of adipose tissue were noted throughout the
lesion. Furthermore, the size of the mass at 11 cm was, in itself,
unusual for a benign adenoma.
Initial diagnostic considerations included a primary adrenal
cortical malignancy, a metastatic lesion from an occult primary,
and a myelolipoma. Pheochromocytoma and adenoma were believed to be
because of atypical imaging characteristics.
A subgroup of adrenal adenomas are large and heterogeneous. They
calcify more frequently, and have areas of internal hemorrhage and
necrotic components. They may show foci of fatty metaplasia. All of
these characteristics are responsible for the bizarre imaging
features. Imaging features alone frequently cannot differentiate
these lesions from other large adrenal masses, such as
adreno-cortical carcinoma and metastases. Surgical resection may be
required for a definitive diagnosis.