Adrenal Masses: Benign or Malignant?

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Erica McAuliffeGillian Lieberman, MD

Adrenal Masses: Benign or Malignant?

Erica McAuliffe, Harvard Medical School Year IIIGillian Lieberman, MD

March 2002

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RightAdrenal

LeftAdrenal

Normal Adrenal Anatomy

Netter, Frank. Atlas of Human Anatomy. 2nd edition. Novartis: 1997.

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http://www.vh.org/Providers/Textbooks/LungTumors/CaseStudies/Patient004/Text/CTCompAdrenalMets.html

Normal Adrenal CT

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Glucocorticoids

Sex Steroids

Mineralocorticoids

Normal Adrenal Histology

From http://www.vh.org/Providers/Textbooks/MicroscopicAnatomy/Section15/Plate15293.html

Catecholamines

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Why Look at Adrenals?• Endocrine workup in a patient with suspicious

symptoms or laboratory values– ie, hypertension, Cushingoid symptoms, virilism,

adrenal insufficiency

• Looking for metastases in a patient with known extra-adrenal malignancy

• Post-trauma abdominal survey

• ANY reason for obtaining a scan of the abdomen– Incidental adrenal masses are detected in 0.35-4.4%

of CT scans done for other reasons.

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Menu of Tests for Evaluating Adrenals

1. Plain Films- Limited role; useful for calcifications

2. Ultrasound- Cyst vs. solid- Intra-operative use in laparoscopic adrenalectomies

3. CT- Procedure of choice for patients with known or

suspected adrenal lesions- Attenuation values useful in differentiating pathology

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Menu of Tests, cont.

4. MRI- Best test for suspected pheochromocytoma- Chemical shift imaging to determine fat content

5. Radioisotope Scanning = Functional imaging- 131I labeled cholesterol analog can detect functional adrenocortical tumors- Labeled guanethidine analog (MIBG) can detect functional adrenomedullary tumors

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Differential Diagnosis of Adrenal Enlargement

• BENIGN– Adenoma - functional– Adenoma - nonfunctional– Adrenal hyperplasia– Pheochromocytoma (90%)– Myelolipoma

• MALIGNANT– 1° adrenal carcinoma– Metastasis– Ganglioneuroma– Neuroblastoma

• OTHER– Cyst– Hematoma/Hemorrhage– Infection

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Our Patient W.W.• Healthy 61 year old man.

• PMH: gout, appendectomy.

• 60 pack-year smoker, quit 13 years ago.

• CXR at outside hospital revealed LUL nodule.

• Referred to BIDMC for further evaluation.

• A chest CT was ordered.

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Our Patient W.W. Chest CT

Lung Nodule

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Patient W.W. – Chest CT Findings

• 1.6 x 1.7 cm spiculated nodule in peripheral aspect of LUL.

• Routine chest CT images include the upper abdomen and both adrenal glands.

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Our Patient W.W.: CT Findings

Renal Mass

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Patient W.W. - CT Findings

• Lung nodule: 1.6 x 1.7 cm spiculated nodule in peripheral aspect of LUL.

• Renal mass: Cystic and solid lesion off upper pole of R kidney, 6.1 x 4.5 cm, consistent with 1° RCC.

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Hemangioma

L adrenal mass:Focal area of higher intensity

Our Patient W.W.: CT with contrast

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Patient W.W. - CT Findings• Lung nodule: 1.6 x 1.7 cm spiculated

nodule in peripheral aspect of LUL.• Renal mass: Cystic and solid lesion off

upper pole of R kidney, 6.1 x 4.5 cm, consistent with 1° RCC.

• Liver lesion: 3.2 cm lesion in caudate lobe, consistent with hemangioma.

• L adrenal mass: Well-circumscribed, fat- containing 1.9 x 1.5 cm mass.

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Erica McAuliffeGillian Lieberman, MD Our Patient W.W.: CT with contrast - R adrenal gland

Lobular areas ofdecreased attenuation

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Patient W.W. - CT Findings• Lung nodule: 1.6 x 1.7 cm spiculated nodule in

peripheral aspect of LUL.• Renal mass: Cystic and solid lesion off upper

pole of R kidney, 6.1 x 4.5 cm, consistent with 1° RCC.

• Liver lesion: 3.2 cm lesion in caudate lobe, consistent with hemangioma.

• L adrenal mass: Well-circumscribed, fat- containing 1.9 x 1.5 cm mass.

• R adrenal mass: Lobular areas of decreased attenuation

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Adrenal Metastases

• Common; can alter treatment options.• Most common primary sites:

– Lung– Breast– Kidney– Bowel– Ovary– Melanoma

• 90% of adrenal masses found in SC lung cancer patients are mets.

• 60% of adrenal masses found in NSC lung cancer patients are mets.

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Benign vs. Malignant?

Benign Adenoma

Metastasis 1° Adrenal Carcinoma

Size Small (< 5cm) Variable, can be bilateral

Often >5cm when detected

CT -Well-defined, -no calcifications, -no hemorrhages < 10 HU

-Heterogenous, -Indistinct margins

-Heterogenous, -Necrosis and hemorrage common

MRI -Low SI -In-phase/out-of-

phase shows drop in SI

-Higher SI than adenoma -No SI drop out on chemical shift MRI

-Hyperintense

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Cotran: Robbins Pathologic Basis of Disease, 6th ed., Copyright © 1999 W. B. Saunders Company

Adrenal Carcinoma Normal Cortical Tissue

Intracellular Lipid Content

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Benign vs. Malignant?

Benign Adenoma

Metastasis 1° Adrenal Carcinoma

Size Small (< 5cm) Variable, can be bilateral

Often >5cm when detected

CT -Well-defined, -no calcifications, -no hemorrhages < 10 HU

-Heterogenous, -Indistinct margins

-Heterogenous, -Necrosis and hemorrage common

MRI -Low SI -In-phase/out-of-

phase shows drop in SI

-Higher SI than adenoma -No SI drop out on chemical shift MRI

-Hyperintense

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MRI Signal Intensity

Weissleder. Primer of Diagnostic Imaging. Mosby, Inc., 1996.

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Primary Adrenal Carcinoma:Patient #2

CT Features:- Large size- Calcification- Extension into liver

- Heterogenous,cystic and solid

From Kaplan, N. The adrenal incidentaloma. Up to Date 10.1., 2002.

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L ADRENAL MASSHU = -5 to +4

Patient W.W. –CT scan without contrast

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Patient W.W.: CT with contrast

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Chemical Shift MRI

• Fat protons and water protons have different resonance frequencies.

• At a known time interval, the protons are out-of- phase, and their signals cancel out.

• By timing images based upon this interval, we can determine the fat content of a certain tissue.

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P. D. Peppercorn, A. B. Grossman & R. H. Reznek (1998). Clinical Endocrinology 48 (4), 379-388.

No loss of signal intensity indicates no intracellularfat.

IN-PHASE

OUT-OF-PHASE

Chemical Shift MRI – Example of Mets

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IN-PHASE OUT-OF-PHASE

Loss of signal intensity indicates presence of intracellular lipid.

Patient W.W.: Chemical Shift MRI of R adrenal mass

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IN-PHASE OUT-OF-PHASE

Patient W.W.: Chemical Shift MRI of L adrenal mass

Signal intensity decreases, except for small central focus.

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Our Patient W.W., cont.

• Uncertainty persisted after CT and MRI.• Percutaneous biopsy done of L adrenal gland.• Pathology revealed benign L adrenal adenoma.• Left upper lobectomy performed --> pathology

revealed adenocarcinoma of lung.

• Right nephrectomy and adrenalectomyperformed --> revealed renal cell carcinoma and… R adrenal myelolipoma.

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• Benign tumors composed of adipose and hematopoietic tissue.

• Radiographic features:– Macroscopic fat (low attenuation)– May enhance with contrast administration– 20% calcify

• No treatment required.

Adrenal Myelolipomas: Patient #3

From Udelsman R. and EK Fishman. Endocrinology and MetabolismClinics of North America. 29(1), March 2000.

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Adrenal mass

Not hyperfunctioning Biochemistry Functioning

> 3cm Size Surgery< 3cm

Biopsyor surgery

Chemical-Shift MRI

HU < 10

Non-contrast CT

CT attenuation value

Benign adenoma

HU > 10

Chemical-shift MRIor biopsy

Signal intensity

Biopsy orsurgery

No lossLoss

Benign adenoma

EITHER

Algorithm for incidental adrenal mass

From Sohaib, SAA and RH Reznek. BJU International (2000), 86 Suppl.1, 95-110.

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Differential Diagnosis of Adrenal Enlargement

• BENIGN– Adenoma - functional– Adenoma - nonfunctional– Adrenal hyperplasia– Pheochromocytoma (90%)– Myelolipoma

• MALIGNANT– 1° adrenal carcinoma– Metastasis– Ganglioneuroma– Neuroblastoma

• OTHER– Cyst– Hematoma/Hemorrhage– Infection

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References• Bergman, RA, AK Afifi, PM Heidger, University of Iowa, 2001:

http://www.vh.org/Providers/Textbooks/MicroscopicAnatomy/Section15/Plate15293.html• Busick, NP, PC Fretz, JR Galvin, MW Peterson, and CE Platz, Univ. of Iowa, 2000:

http://www.vh.org/Providers/Textbooks/LungTumors/CaseStudies/Patient004/Text/CTCompAdrenalM ets.html

• Cotran et al., ed.: Robbins Pathologic Basis of Disease, 6th ed., W. B. Saunders Company, 1999.

• Kaplan, NM. The adrenal incidentaloma. UpToDate, online 10.1. 2002.• Netter, Frank. Atlas of Human Anatomy. 2nd edition. Novartis: 1997.• Pender, SM, GW Boland, and MJ Lee. The incidental nonhyperfunctioning adrenal

mass: an imaging algorithm for characterization. Clinical Radiology (1998), 53: 796-804• Peppercorn, PD, AB Grossman, and RH Reznek. Imaging of incidentally discovered

adrenal masses. Clinical Endocrinology (1998), 48: 379-388.• Sohaib, SAA and RH Reznek. Adrenal imaging. BJU International (2000), 86 Suppl.1:

95-110.• Udelsman, R. and EK Fishman. Radiology of the adrenal. Endocrinology and

Metabolism Clinics of North America (2000), 29(1): 27-42.• Weissleder. Primer of Diagnostic Imaging. Mosby, Inc., 1996.

http://www.vh.org/Providers/Textbooks/MicroscopicAnatomy/Section15/Plate15293.html

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Acknowledgments

• Damon Soiero, MD• Haldon Bryor, MD• Jonathan Kruskal, MD• Gillian Lieberman, MD• Pamela Lepkowski• Webmasters Larry Barbaras and Cara Lyn

D’amour

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Adrenal Masses: Benign or Malignant?