Anatomy,relations,tumour of adrenal gland.

1. PRESENTED BY: :
DR. BHISHM PRATAP SEVENDRASEEN BY :DR. KANCHANA PACHHIGAR

2. Anatomy
 Each adrenal gland have a body and two limbs -
medial and lateral.
 The right adrenal gland is pyramidal in shape
while the left adrenal gland is crescenteric .
 Each adrenal gland is enclosed in the perirenal
fascia .

4.  Each limb normally measures <5mm in width and
the body should measure <10mm in width .
 The adrenal size is larger in neonates and infants,
being almost one-third of the size of the kidney .

5. Right adrenal gland
 Right adrenal is seen directly superior to the
upper pole of the right kidney, with its most caudal
portion just anterior to the upper pole.
 CT: linear, V-shape or comma-shape .

6. Relations
 medial - right crus of the diaphragm, right inferior
phrenic nerve.
 lateral - right lobe (bare area) of the liver
 anterior - IVC
 posterior - right kidney

7. Right crus of diaphragm
IVC
Right adrenal gland
Right lobe of liver

8. Left adrenal gland
The left adrenal may be seen at the same level as
the right, but often it is slightly more caudal.
It is antero-medial to the upper pole of the left
kidney.
CT: in the same slice as the left kidney & appears
as a triangular or Y-shape .

9. Relations
 Medial - left crus of the diaphragm, left inferior
phrenic nerve.
 Antero-medial – diaphragm.
 Anterior - less sac, stomach, splenic artery,
pancreas.
 Posterior & laterally- left kidney

10. Left adrenal gland

11. Left crus of diaphragm
Left kidney
stomach
Splenic artery
pancreas

12. Tumours of the adrenal gland
 Adrenal adenoma
 Adrenal carcinoma
 Pheochromocytoma
 Neuroblastoma
 Adrenal metastases
 Adrenal myelolipoma

13. Adrenal adenoma
 Commonest adrenal mass lesion.
 Often found incidentally termed “incidentaloma”.
 Incidence: increase in frequency with age.

14.  Majority: non-functioning (asymptomatic).
 In all cases, but especially in the setting of known
current or previous malignancy, adrenal adenomas
need to be distinguished from adrenal
metastasis or other adrenal malignancies.

15. CT
 two properties that differentiate them from non-
adenomas.
1. 70% of adenomas : lipid-rich(HU<10).
2. Adenomas rapidly wash out contrast.
30% of adenomas: lipid-poor (HU >10), and
cannot be differentiated from malignant masses on
an unenhanced CT .

16. CT-Algorithm benign versus
malignant

17. Enhanced and Delayed
scan
On the initial enhanced CT (at 60 sec):
 Most adenomas : mild enhancement.
 Malignant tumors and pheochromocytoma :
strong enhancement.
 but there is too much overlap in attenuation
values to allow differentiation between
malignant and benign.

18.  A number of these adenomas however can be
differentiated from malignant masses on the basis
of their fast wash-out of contrast.
The wash-out can be calculated by comparing the
attenuation value at 60 sec with the attenuation
value on a delayed scan at 15 minutes.

19. Absolute enhancement wash out > 60% = adenoma. Relative enhancement wash out >
40% = adenoma.

20. dedicated adrenal protocol in a patient with an adrenal mass.
On the unenhanced CT : well defined small homogeneous mass
HU=9.which is characteristic of a lipid-rich adenoma.
i.v. contrast was given to determine the washout.
The enhancement washout = (43 - 22) : (43 - 9) = 62% indicating
a fast washout characteristic of an adenoma.

21. Typical nonenhanced CT findings of an adrenal adenoma in a 64-year-old man with no
known malignancy. The left adrenal adenoma has smooth margins, is well defined, and
has a attenuation of 5 HU, all findings characteristic of an adenoma.

22. MRI
 Chemical shift imaging: is the most reliable for diagnosis
especially when CT findings are equivocal.
 It has high sensitivity to minute amounts of intravoxel fat.
 On opposed-phase: a drop in signal intensity of greater
than 20% is considered diagnostic for an adenoma .
Signal intensity index=SI on in phase-SI on opposed phase x100
SI on in phase

23.  Rather than measuring the signal, one can
compare the adenoma in and out of phase, with
images windowed similarly (using the spleen or
muscle as a reference )
 Do not use the liver as it can change signal on in
phase and out of phase imaging depending on
presence of hepatic steatosis) .

24. right adrenal lesion in T1 in phase image appears iso-intense to liver

25. Signal drop in right adrenal lesion in T1 out phase image

26. Adrenal cortical carcinoma
 A primary adrenal cortical
carcinoma is a highly malignant but
rare neoplasm.
 It may present as a hormonally active or
inactive tumour.

27.  CT
 A large inhomogeneous mass with heterogeneous
enhancement.
 Central necrosis is common.
 Calcification is seen in 20-30% of cases.

32. A 68-year-old woman with a large right upper quadrant primary adrenocortical carcinoma
with curvilinear calcification. Low-attenuation regions anteriorly are consistent with
necrosis

33. MRI
 Useful to determine hepatic invasion if CT is
inconclusive.
 Heterogeneous mass is seen that is of high signal
on T2 sequences.
 Heterogeneous enhancement is seen with
administration of gadolinium.

34. Adrenal metastases
 Most common malignant lesions.
 Metastases are usually bilateral but may also be
unilateral.

35. Morphologic criteria with the density
measurements on unenhanced CT.
 high accuracy in differentiating adrenal
adenomas from metastases in patients with a
known malignancy.
 scoring system :
In patients with a known extra-adrenal malignancy a total score > 7 points was highly
accurate for the diagnosis metastasis.

36.  CT
 variable appearances .
 Usually demonstrates less than 50%
washout.

43.  MRI
Exact signal characteristics depend on the type of
tumour.
 T1 - low signal intensity.
 T2 - high signal intensity.
 C+ (Gd) - usually has progressive enhancement
after administration of contrast material .
 An important diagnostic feature is the lack of
signal loss on out-of-phase images (in
contradistinction to that seen with adrenal
adenoma)

44. T1-weighted MRI demonstrates left adrenal metastasis in a patient with previous
resection of the right liver lobe for metastasis.

45. Pheochromocytoma
 Uncommon tumour of the adrenal gland, with
characteristic clinical, and to a lesser degree,
imaging features.
 The tumours follow a 10% rule:
 ~ 10% are extra-adrenal
 ~ 10% are bilateral
 ~ 10% are malignant
 ~ 10% are found in children
 ~ 10% are familial
 ~ 10 % are not associated with hypertension

46.  Radiographic features.
 large at presentation, average size of ≈ 5 cm.
 Not possible to distinguish malignant from benign
pheochromocytoma merely on the
direct appearance of the mass.
 Distinction is made on :evidence of direct tumour
invasion /presence of metastases .

47. CT
 Large heterogeneous masses with areas of
necrosis and cystic change.
 Up to 7% demonstrate areas of calcification .
 Contrast may be contraindicated as it could
precipitate a hypertensive crisis.

48. MRI
 most sensitive .
 particularly useful in cases of extra-adrenal location.
 T1
 slightly hypointense .
 T2
 markedly hyperintense .
 T1 C+ (Gd)
 heterogenous enhancement
 enhancement is prolonged.

49. Pheochromocytoma on CT and MRI. There is strong enhancement on enhanced CT
and very high signal intensity on T2-weighten MRI.

50. Neuroblastoma
 The most common extracranial solid childhood
malignancies and the third commonest childhood
tumor after leukemia and brain malignancies.

51. CT
 CT: heterogeneous with calcifications.
 The morphology of is often most helpful, with the
mass seen insinuating itself beneath the aorta and
lifting it off the vertebral column. It tends
to encase vessels and may lead to compression.
 Adjacent organs are usually displaced, although in
more aggressive tumours direct invasion of the
psoas muscle or kidney can be seen.

52.  MRI
 T1 - heterogeneous and iso to hypointense
 T2 -
 heterogeneous and hyper intense.
C+ (Gd) - variable and heterogeneous enhancement

53. Neuroblastoma
 calcification ( 90%)
 encases vascular structures but does not invade
them
 younger age group (< 2 years of age)
 poorly marginated
 more common to have extension into chest
 elevates the aorta away from the vertebral column

54. Wilms tumour
 calcification :(10 - 15%)
 displaces adjacent structures with out
insinuating between them.
 well circumscribed
 slightly older age group : peak 3 - 4
years of age
 extension into IVC / renal vein

55. neuroblastoma Wilms tumour

56. Adrenal myelolipoma
 Adrenal myelolipomas are rare benign
tumours of the adrenal gland.

57. CT
 Well circumscribed mass with fat-containing
components.
 calcifications may be seen.

58. MRI
 T1 - hyper intense.
 T1 (FS) - shows fat suppression.
 T2 - intermediate to hyper intense.
 T1 C+ (Gd) - shows striking enhancement.
 in and out of phase - demonstrate signal loss as
the macroscopic fat cells usually have little
intracellular water .

59. Bilateral myelolipoma in a 79-year-old man. Nonenhanced CT scan shows an exophytic
mass of fat attenuation (straight arrow) in the right adrenal gland. The left
adrenal gland has a soft-tissue mass containing calcifications and a central area of fat
attenuation (curved arrow).

60. LEFT: adrenal mass containing islands of fat specific for the diagnosis myelolipoma.
RIGHT: different case with high SI on T1WI indicating fat in myelolipoma.

61. Adrenal hyperplasia
 Adrenal hyperplasia refers to non malignant
growth (enlargement) of the adrenal glands.
 cause of 70% of the cases of Cushing's syndrome
and 20% of the cases of Conn syndrome.
 In diffuse hyperplasia, the limbs of the adrenal
glands exceed 5mm thickness.

63. THANK YOU..