The document summarizes the multimodality evaluation of adrenal masses. It discusses the characteristic imaging findings of common benign and malignant adrenal masses using CT, MRI, PET, and other imaging modalities. The goals are to review the spectrum of imaging findings and differentiate between benign and malignant adrenal masses. Common benign entities discussed include adenomas, hemorrhage, myelolipomas, pheochromocytomas, and cysts. Malignant entities covered are metastases, adrenocortical carcinomas, lymphomas, and others.

1. Multimodality Evaluation of Adrenal
Masses
Peeyush Bhargava MD MBA, Michael C Gates MD,
Guillermo Sangster MD, David Wallace MD,
Matias Migliaro MD, Jaiyeola Thomas-Ogunniyi MD
Louisiana State University Health Science Center, Shreveport, LA
ARRS, April 2016, Los Angeles, CA

2. Goals and Objectives
• Review the spectrum of characteristic imaging
findings of adrenal masses using a
multimodality approach
• Discuss the findings that can differentiate
between benign and malignant adrenal masses
• Target Audience: Radiology residents and
practicing Radiologists

3. Benign Adrenal Masses
• Adenoma
• Incidentaloma
• Hemorrhage
• Myelolipoma
• Hyperplasia
• Pheochromocytoma
• Collision Tumor
• Ganglioneuroma
• Lipoma
• Cyst
• Oncocytoma
• Infection / Shock Adrenal

4. Adenomas
• Most common adrenal tumor and incidentaloma
• Benign, most non functional
• 70% lipid rich, 30% lipid poor
• 1-4 cm, well defined, solid, homogenous, smooth
• Yellow to yellowish-brown in color
• Vacuolated cells with intra-cytoplasmic lipid

5. Adenomas
• CT features:
Unenhanced - < 10 HU
Enhanced - > 60% Absolute percentage washout
Enhanced - > 40% Relative percentage washout
• MRI features:
Chemical shift imaging - signal drop on out of phase
Adrenal to spleen ratio - < 71%
Adrenal signal intensity index - < 16.5%

6. Adrenal Adenoma on CT
Lipid Rich

7. Adrenal Adenoma
MRI In/Out of Phase
ININ
OUT OUT

8. Absolute washout = (110 – 60 / 110 – 50) x 100 = 83%
Relative washout = (110 – 60 / 110 ) x 100 = 45%
Adenoma: APW, RPW

9. History: Incidental adrenal mass: 50 HU / 110 HU / 60 HU
Absolute washout = (110 – 60 / 110 – 50) x 100 = 83%
Relative washout = (110 – 60 / 110 ) x 100 = 45%

10. Incidentaloma
• Adrenal tumors seen in 4 – 10 % of abdominal CTs
• Most common lesion is an adenoma
• Functional vs non-functional – 24 hr urine
metanepnrines, 17 hydroxycorticosteroids, 17
ketosteroids
• CT / MRI characteristics – size, margins, HU / signal
drop on chemical shift / washout, homogeneity,
growth, history of cancer
• PET/CT imaging / Biopsy

11. Algorithm for Adrenal Incidentaloma
Managing incidental findings on abdominal CT: white paper of the ACR incidental findings committee.
J Am Coll Radiol. 2010 Oct;7(10):754-73. doi: 10.1016/j.jacr.2010.06.013.

12. Hemorrhage
• Traumatic (non accidental in peds) vs non traumatic
• Non traumatic causes: coagulopathy, stress (sepsis,
surgery, burns, hypotension, pregnancy), venous
hypertension and hemorrhagic tumor
• 20% are bilateral, 1- 5 cm, well defined, round

13. Hemorrhage
• CT: high attenuation (50-90 HU), does not
enhance, decreases in size and attenuation with
time, fat stranding, extension
• MRI:
Acute (<7 days) – T1 iso to hypo, T2 markedly hypo
Subacute (1-7 wks) – T1 fat sat and T2 hyperintense
Chronic (after 7 wks) – T1 and T2 hypointense rim

14. Adrenal Hematoma
Sag
Ax
Sag
Ax Cor

15. Adrenal Hematoma
Cor Sag
Ax

16. Shock Adrenal (Hypoperfusion complex)
Ax Cor

17. Myelolipoma
• Benign and non functioning tumor
• Mature adipose and hematopoeitic tissue
• Heterogeneous, pseudo-capsule, calcifications
• US: hyperechoic lesion
• CT: macroscopic fat (HU<30)
• MRI: T1 hyperintense signal suppresses with fat sat
India ink (chemical shift) artifact at myeloma-adrenal
interface and within the mass on out of phase

18. Myelolipoma
Ax Cor

19. Myelolipoma

20. Myelolipoma
Pre Pre
PostPost

21. Hyperplasia
• Benign and functional
• Accounts for 2% cases of Cushings syndrome
and 30% cases of primary hyperaldosteronism
• Sex steroid over production can lead to
feminization or virilization
• Diffuse vs macronodular

22. Adrenal Hyperplasia (2 patients)

23. Pheochromocytoma
• Arises from Chromaffin cells in adrenal medulla
• Stores and releases catecholamines
• Elevated serum / 24 hr urine metanephrines
• Hypertension, palpitations, perspiration and headache
• 10% are: bilateral, extra adrenal (paragangliomas), occur
in children, and malignant (local invasion and mets)
• Association with syndromes: MEN, NF 1, Von Hippel
Lindau, Tuberous sclerosis, Sturge-Weber

24. Pheochromocytoma
• CT: homogeneous, well defined, soft tissue attenuation,
avid enhancement with delayed retention
• MR: T2 bright (light bulb)
• Take up I123 MIBG, In111 pentetreotide, and F18 FDG
• Surgical resection
• Pathology: yellow / tan, hemorrhage, cystic change,
central necrosis, myxoid degeneration. Nest of cells
(zellballen), Salt and pepper chromatin

25. Pheochromocytoma

26. Pheochromocytoma
Ax Cor

27. Metastatic Pheochromocytoma on
F-18FDG PET and I-123MIBG

28. Collision Tumor
• Two coexisting histologically distinct tumors
• Benign: adenoma and myelolipoma
• Malignant: adenoma and metastasis

29. Cyst
• Rare, benign, and non functional
• Cystic, fluid attenuation, septations
• Rim calcification, non enhancement
• Prior hemorrhage or infarct
• Aspirated if clinically indicated
• Acellular turbid fluid with cholesterol crystals
• Differentiate from cystic neoplasm (CT / MRI)

30. Calcified Cystic Adrenal Mass
Ax Ax
SagCor

31. Malignant Adrenal Masses
• Ganglioneuroblastoma
• Neuroblastoma
• Oncocytoma
• Angiosarcoma
• Metastasis
• Pheochromocytoma
• Adrenocortical carcinoma
• Lymphoma
• Collision tumor

32. Metastasis
• Common site after lung, liver, and bone
• Primary: lung, breast, thyroid, colon, melanoma
• Irregular, poorly defined mass, heterogeneous
• Rim / nodular enhancement, central necrosis
• Local invasion, hemorrhage
• Rapid growth, other mets
• T2 bright, no change on chemical shift imaging
• FDG avid on PET/CT (SUV > 2.5 / liver)

33. Bilateral Adrenal Mets
Cor Ax
Ax

34. Adrenocortical Carcinoma
• Arise from adrenal cortex, aggressive tumor
• 1st and 4th/5th decade, rare cancer
• Large palpable mass with abdominal / flank pain
• >6 cm at presentation, likely to be functional
• Invasive (adrenal vein and IVC) and metastasis to
lung, liver, and bone
• Calcification, central necrosis, hemorrhage

35. Adrenocortical Carcinoma
• Associattions: Li-Fraumeni syndrome, Carney
complex, Beckwith-Wiedemann syndrome, familial
adenomatous, polyposis coli, MEN type 1
• CT: heterogenous / nodular rim enhancement
• MR: T2 hyperintense, hetergenous enhancement with
slow washout
• FDG avid on PET/CT
• Surgical resection, embolization, ablation, no biopsy

36. Adrenocortical Carcinoma
Ax Cor

37. Lymphoma
• Diffuse or focal involvement
• Primary adrenal lymphoma is rare
• Usually NHL with other involvement
• Central necrosis and lymphadenopathy
• FDG avid on PET/CT

38. Ganglioneuroblastoma
• Rare tumors with intermediate malignant potential
• Mostly seen in children 2-4 yrs of age
• Cystic to solid depending on the predominant tissue
component
• Encapsulated, with thin calcifications

39. Neuroblastoma
• Most common extracranial solid tumor of childhood
• Arises from adrenal medulla or retroperitoneal
sympathetic ganglia
• Soft tissue masses, often calcified
• Often with disseminated disease

40. Contact Information
Peeyush Bhargava MD MBA
PGY 3 Radiology Resident
Phone: 832-374-2110
pbharg@lsuhsc.edu
Louisiana State University Health Science Center, Shreveport, LA