31-year-old woman with no significant past medical history presented to the gynecological service with right upper quadrant and mid-upper abdominal pain.
Prepared by Feng Tao, MD, Evan Mortan, MD, and Stephen C.
Machnicki, MD from the Department of Radiology, and Ljiljana
Vasovic, MD and Frank Breuer, MD from the Department of
Pathology, Lenox Hill Hospital, New York, NY; and Richard A.
Heiden, MD from the Department of Radiology, Interfaith Medical
Center, Brooklyn, NY.
A 31-year-old woman with no significant past medical history
presented to the gynecological service with right upper quadrant
and mid-upper abdominal pain. On physical examination, cervical
motion tenderness was induced. The patient was admitted to receive
intravenous antibiotic treatment for presumed pelvic inflammatory
disease. However, laboratory and radiological workup were
subsequently negative and her symptoms quickly improved. A week
later, she returned to surgical clinic complaining of recurrent
right upper quadrant pain. A computed tomography (CT) scan revealed
a large complex cystic lesion in the right upper quadrant. Further
evaluation with magnetic resonance imaging (MRI) and ultrasound did
not delineate the origin of the cyst clearly. Serological studies
excluded the possibilities of echinoccocal disease.
An exploratory laparoscopy was performed. The postoperative
course was uneventful, and the patient did well. Cytology of the
aspirated fluid showed no malignancy or bile.
Right adrenal gland benign true cyst with degeneration and
Computed tomography (figure 1) scan demonstrated an 8.0-cm
thick-walled, multi-loculated cystic structure in the right
suprarenal area, with calcifications.
Ultrasound (figure 2) demonstrated a bilobed cystic mass either
adjacent to or in the posterior aspect of the right lobe of the
liver. This complex cystic mass had thick walls, internal debris,
Magnetic resonance imaging (figure 3) demonstrated a large,
complex bilobed cystic mass in the right upper quadrant measuring
approximately 7.8 * 7.8 * 9.0 cm in antero-posterior, transverse,
and craniocaudal dimensions, respectively. No normal right adrenal
gland was identified. It was uncertain whether this mass arose from
the right adrenal gland or from the right lobe of liver.
The radiological differential diagnosis included a hemorrhagic
cyst, infectious cysts (such as a hydatid cyst or abscess from the
adrenal gland or the right lobe of the liver), an adrenal
pseudocyst, an adrenal true cyst, or cystic neoplasms of right
adrenal gland (such as adrenal cortical adenoma, carcinoma, and
Intraoperatively, a large cyst was found in the retroperitoneal
space posterior to the right lobe of the liver. Clear yellow fluid
was aspirated. The cyst was unroofed and partially removed. Gross
pathological examination showed a cyst filled with proteinacious
material. Microscopic examination of the cyst wall (figure 4)
demonstrated adrenal cortical tissue and a broad zone of hyalinized
collagen, which showed erosion, degeneration, calcification, and
focal lymphocyte infiltration. A single layer of benign-appearing
cuboidal cells with convex apical surface lined a portion of the
inner surface of the cyst. Immunohistochemical studies revealed
(figure 5) positive staining of these cuboidal cells for
cytokeratin and calretinin, and negative for CD34, indicating a
Adrenal cysts are rare
(0.064% to 0.18% in autopsy series), and fewer than 500 cases have
been reported in the Western literature. Traditionally, adrenal
cysts have been divided into four general groups
: 1) endothelial lined cysts (45%); 2) pseudocysts (39%); 3) cysts
secondary to infectious agents, such as echinococci; and 4)
epithelial-lined or true adrenal cysts (9%). In addition, adrenal
cystic neoplasm, dermoid cysts, and lymphangioma
have been reported. Of these, endothelial-lined cysts and
pseudocysts are most common and comprise approximately 90% of
cases. Epithelial-lined true cysts are rare, and theoretically
could be retention cyst (glandular), or arising from adrenal
cortical adenoma and embryonal cyst. Some authors doubt the
existence of true adrenal cyst.
Unfortunately, clinical and imaging findings alone,
and even fine-needle aspiration, cannot always make the diagnosis
and distinguish these lesions. Surgical biopsy is always needed.
Therefore, adrenal cysts can present a difficult diagnostic
problem. The importance of accurately diagnosing adrenal cysts lies
in separating them from cystic lesions in adjacent organs (such as
the kidneys, spleen, and liver), and predicting the benign or
malignant nature of the lesion. Ultrasound, CT, and MRI
have been reported to have diagnostic sensitivities of 66.7%, 80%,
and 100%, respectively.
Retrospective review of the ultrasonographic features of adrenal
revealed that focal absence of periglandular fat between the
adrenal gland and the large vessels or liver, as well as deviation
or compression of the large vessels by the adrenal lesion, may
indicate malignancy. In addition, adrenal tumors, benign or
malignant, were often associated with a prominent uterus, uterine
stump, or prostate with or without prostatic cysts.
Evidence of lipid content of adrenal cysts is clearly
demonstrated on ultrasound, CT, and MRI.
Nevertheless, the histology type cannot be predicted.
A report of the MRI features of adrenal pseudocysts
showed two components: 1) a large component with low signal
intensity on both T1- and T2-weighted images and 2) a second,
smaller, fluid component. These features are not specific, however,
as an adrenal adenoma may have a similar appearance.
Previous experience demonstrates that a careful hormonal (for
functional cyst), morpho-functional, and instrumental evaluation is
indicated in all adrenal cysts, because even when the available
diagnostic modalities are combined, they cannot always define the
nature of these cysts. Surgical excision, when possible by
laparoscopic approach, is indicated in the presence of symptoms,
endocrine abnormalities (even when subclinical), complication and
suspicion of malignancy, and/or large size (>5 cm). Such is also
the case for cystic large adrenal adenoma,
which can present with a heterogeneous, more frequently calcified
The management of adrenal cysts depends on clinical and imaging
findings and diagnosis. Symptomatic ones should be resected, but
small, asymptomatic, non-functional cysts with benign
characteristics may be treated conservatively with regular
follow-up by sonography or CT and hormonal evaluation,
as malignant cystic tumors are uncommon. The finding of clear
liquid and nonmalignant cell cytology practically excludes
Furthermore, cystic adeno-carcinomas are usually large and the
cystic fluid is cloudy with abundant cellularity.
Giant adrenal cysts are usually pseudocysts,
and these usually occur in elderly patients. However, a recent
report showed giant adrenal cysts occurring in three teenage girls.
Adrenal cysts can be associated with certain medical conditions
such as hepatic focal nodular hyperplasia,
hypertension, and pregnancy.
Co-existence of adrenal cystic lymphangiomas with nevoid basal cell
carcinoma (Gorlin-Goltz) syndrome were reported with ultrasound and
Finally, radiological differential diagnosis of adrenal cysts
should always include cystic lesions in the adjacent organs such as
the liver, spleen, and kidneys, cystic retroperitoneal tumors, and
other rare congenital abnormalities, such as bronchogenic cysts.
In summary, a case of adrenal true (epithelial) cyst, a rare
entity, is reported here with its radiological and pathological
findings. The diagnosis of different types of adrenal cystic
lesions and their differentiation from cystic lesions of the
adjacent organs are critical for clinical management. The
combination of clinical, laboratory, and imaging findings is
essential. A few promising imaging and laboratory characteristics
have been reported that may be of use in the diagnosis of adrenal
cysts. It is important for the radiologist to be familiar with the
characteristic appearances of different cystic adrenal lesions in
order to guide diagnosis and patient management.