II. Epidemiology

  1. Incidental Adrenal Mass found on up to 3-4% of Abdominal CTs or MRIs
  2. Incidental Adrenal Masses found in 20% of autopsies

III. Differential Diagnosis of Incidental Adrenal Mass

  1. Adrenal Adenoma (51%)
    1. Non-functioning adenoma
    2. Functioning adenoma
      1. Cushing's Syndrome
      2. Pheochromocytoma
      3. Hyperaldosteronism
  2. Metastatic cancer (31%)
    1. Bronchogenic Carcinoma
    2. Renal Cell Carcinoma
    3. Melanoma
  3. Adrenal Carcinoma (1-4%)
  4. Adrenal Cyst (4%)
  5. Pheochromocytoma (4%)
  6. Adrenal Hyperplasia (2%)
  7. Lipoma (2%)
  8. Myelolipoma (2%)

IV. Labs

  1. Pheochromocytoma Screening
    1. Consider plasma free metanephrines (in all patients)
    2. 24-hour Urine Metanephrines
    3. 24-hour Urine Vanillylmandelic Acid (VMA)
  2. Cushing's Syndrome Screening
    1. Dexamethasone Suppression Test (in all patients)
    2. 24-hour Urinary free cortisol level
  3. Hyperaldosteronism Screening (hypertensive patients)
    1. Serum Potassium
    2. Plasma Aldosterone to renin activity ratio

V. Imaging

  1. CT Abdomen
    1. With IV contrast
      1. Low attenuation lesions (<10 Hounsfield Units) is more consistent with benign lesions
    2. With delayed-phase (to perform washout calculations)
      1. Adrenal carcinoma has a low washout
  2. MRI Abdomen with Chemical Shift
    1. Chemical shift confirms lipid-rich adenoma
    2. Indicated if CT with IV contrast contraindicated
  3. Fluorodeoxyglucose-positron emission testing (FDG-PET)
    1. Indicated for lesions not definitively characterized on CT or MRI
    2. High Test Sensitivity for malignancy
    3. Decreased Test Specificity for malignancy (False Positives possible)

VI. Evaluation: Reassuring findings suggestive of benign Adrenal Mass

  1. No history of other malignancy (lowers risk to 0.3% chance of cancer)
  2. Reassuring imaging findings suggestive of benign mass
    1. Lesions smaller than 4 cm with smooth borders
    2. Lipid-containing lesions
      1. CT with low attenuation (<10 Hounsfield Units) homogeneous mass
      2. MRI with signal loss on out-of-phase imaging
    3. Rapid-washout of IV iodinated contrast

VII. Indications: Follow-up Imaging

  1. Distinguish benign Lesions versus cancer
  2. Distinguish functioning versus non-functioning

VIII. Evaluation: Protocol

  1. Adrenal Mass on CT Scan <1 cm in greatest diameter (especially if fatty or cystic consistency)
    1. No further evaluation needed
  2. Adrenal Mass on CT Scan >4 cm in greatest diameter
    1. Evaluate endocrine labs above (especially to rule out Pheochromocytoma)
    2. Imaging
    3. Biopsy unless clearly benign (e.g. adrenal cyst, myelolipoma)
    4. Consult with surgery regarding possible excision
  3. Adrenal Mass 1-4 cm and lipid containing lesion on initial imaging (see above)
    1. Consider evaluating endocrine labs above (especially to rule out Pheochromocytoma)
    2. Repeat unenhanced CT Abdomen in 12 months to confirm no change
  4. Adrenal Mass 1-4 cm and not a lipid containing lesion
    1. Evaluate endocrine labs above (especially to rule out Pheochromocytoma)
    2. Perform CT Abdomen with IV contrast and delayed phase (or MRI as alternative)
    3. If CT or MRI non-diagnostic, consider FDG-PET
    4. Referral
      1. Endocrinology for functional adenomas
      2. General surgery for suspicious or non-diagnostic imaging

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Related Studies

Ontology: Adrenal Gland Neoplasms (C0001624)

Definition (MSHCZE) Nádory nebo rakovina NADLEDVIN.
Definition (NCI) A benign or malignant (primary or metastatic) neoplasm affecting the adrenal glands.
Definition (MSH) Tumors or cancer of the ADRENAL GLANDS.
Definition (CSP) new abnormal adrenal gland tissue that grows by excessive cellular division and proliferation more rapidly than normal and continues to grow after the stimuli that initiated the new growth cease.
Concepts Neoplastic Process (T191)
MSH D000310
SnomedCT 127021009
English Neoplasm, Adrenal Gland, Neoplasms, Adrenal Gland, ADRENAL GLAND NEOPL, NEOPL ADRENAL GLAND, neoplasm of adrenal gland (diagnosis), neoplasm of adrenal gland, Adrenal neoplasm NOS, Adrenal neoplasms, Neoplasm adrenal, adrenal neoplasm, adrenal tumor, Adrenal Gland Neoplasms [Disease/Finding], Neoplasms, Adrenal, Neoplasm, Adrenal, Adrenal Neoplasm, adrenal gland neoplasms, adrenal gland tumor, adrenal gland tumours, adrenal neoplasms, adrenal tumours, tumor of adrenal gland, adrenal tumour, adrenal gland tumour, adrenal glands tumors, adrenal tumors, adrenal gland neoplasm, adrenal glands tumor, tumor adrenal gland, adrenal gland tumors, Adrenal glands--Tumors, Adrenal neoplasm, Adrenal tumor, Adrenal tumour, Tumor of adrenal gland, Tumour of adrenal gland, Neoplasm of adrenal gland (disorder), Neoplasm of adrenal gland, Adrenal Gland Neoplasm, Adrenal Gland Tumor, Adrenal Neoplasms, Adrenal Tumor, Neoplasm of Adrenal Gland, Neoplasm of the Adrenal Gland, Tumor of Adrenal Gland, Tumor of the Adrenal Gland, Adrenal Gland Neoplasms
Italian Tumore surrenale, Tumori della ghiandola surrenale, Tumore surrenale, NAS, Neoplasie della ghiandola surrenale
Dutch neoplasma bijnier, bijnierneoplasma NAO, bijnierneoplasmata, bijnierneoplasma, Bijnierneoplasma, Bijnierneoplasmata, Bijniertumor, Neoplasma, bijnier-
French Tumeur surrénalienne SAI, Tumeur surrénalienne, Tumeurs de la surrénale, Tumeurs surrénaliennes, Tumeurs de la glande surrénale, Tumeurs des surrénales
German Neubildung der Nebenniere NNB, Neubildung der Nebenniere, Neubildungen der Nebenniere, Nebennierentumoren
Portuguese Neoplasia supra-renal NE, Neoplasias das Glândulas Suprarrenais, Neoplasia supra-renal, Neoplasias da glândula supra-renal
Spanish Neoplasia de las glándulas suprarrenales NEOM, Neoplasia suprarrenal, neoplasia de la glándula suprarrenal (trastorno), neoplasia de la glándula suprarrenal, Neoplasia de las glándulas suprarrenales, Neoplasias de la glándula suprarrenal, Neoplasias de las Glándulas Suprarrenales
Japanese 副腎の新生物, 副腎新生物NOS, フクジンシンセイブツNOS, フクジンノシンセイブツ, フクジンシンセイブツ, 副腎新生物, 副腎腫瘍
Swedish Binjuretumörer
Finnish Lisämunuaisten kasvaimet
Russian NADPOCHECHNIKOV NOVOOBRAZOVANIIA, НАДПОЧЕЧНИКОВ НОВООБРАЗОВАНИЯ
Czech Novotvar nadledvin NOS, Novotvar nadledvin, Adrenální novotvar, Nádory nadledvin, nadledviny - nádory, nádory nadledvin
Croatian NADBUBREŽNA ŽLIJEZDA, TUMORI
Polish Nowotwory nadnerczy
Hungarian Mellékvese neoplasia, Adrenalis daganat, Mellékvese neoplasia k.m.n., Mellékvese neoplasmák
Norwegian Binyresvulster, Binyretumorer, Binyreneoplasmer

Ontology: Adrenal Cortical Adenoma (C0206667)

Definition (NCI_CDISC) A benign neoplasm arising from any of the adrenal cortical layers.
Definition (NCI) A benign neoplasm that can arise from any of the adrenal cortical layers. It can be associated with the overproduction of glucocorticoids (Cushing's syndrome), androgenic or estrogenic steroids (adrenogenital syndrome), or mineralocorticoids (Conn's syndrome). (Sternberg Diagnostic Surgical Pathology, 3rd ed.)
Definition (MSH) A benign neoplasm of the ADRENAL CORTEX. It is characterized by a well-defined nodular lesion, usually less than 2.5 cm. Most adrenocortical adenomas are nonfunctional. The functional ones are yellow and contain LIPIDS. Depending on the cell type or cortical zone involved, they may produce ALDOSTERONE; HYDROCORTISONE; DEHYDROEPIANDROSTERONE; and/or ANDROSTENEDIONE.
Concepts Neoplastic Process (T191)
MSH D018246
ICD10 M8370/0
SnomedCT 18365006, 189646008, 134348000, 302826002, 255036008
English Adenoma, Adrenocortical, Adenomas, Adrenal Cortical, Adenomas, Adrenocortical, Adrenal Cortical Adenomas, Adrenocortical Adenomas, Adrenal Cortical Adenoma, ADENOMA ADRENAL, Adenoma of Adrenal Gland, Adenoma of the Adrenal Gland, Adrenal Adenoma, Adrenal Gland Adenoma, Benign Adenoma of Adrenal Gland, Benign Adenoma of the Adrenal Gland, Benign Adrenal Adenoma, Benign Adrenal Gland Adenoma, Adrenocortical adenomas, Adrenal cortic. adenoma NOS, [M]Adrenal cortic. adenoma NOS, Adrenal cortical adenoma NOS, [M]Adrenal cortical adenoma NOS, Adrenal cortical adenoma-morph, Adrenal cortical adenoma - morphology, adrenal cortical adenoma, adrenal cortical adenoma (diagnosis), Adrenal cortical adenoma, no ICD-O subtype, Adenoma adrenal, Adrenocortical Adenoma [Disease/Finding], adenomas adrenal, adenoma adrenal, adrenocortical adenoma, adenoma adrenal cortical, adrenal adenoma, adenoma adrenal cortex, [M]Adrenal cortical adenoma NOS (morphologic abnormality), Adrenal cortical adenoma - morphology (morphologic abnormality), Adrenal cortical adenoma, no International Classification of Diseases for Oncology subtype (morphologic abnormality), Adrenal cortical adenoma, no ICD-O subtype (morphologic abnormality), Adrenal cortical adenoma, no International Classification of Diseases for Oncology subtype, CORTICAL CELL ADENOMA, ADRENAL GLAND ADENOMA, ADRENAL ADENOMA, ADRENAL CORTICAL ADENOMA, ADENOMA OF ADRENAL CORTEX, ADRENOCORTICAL ADENOMA, BENIGN ADENOMA OF ADRENAL GLAND, BENIGN ADENOMA OF THE ADRENAL GLAND, BENIGN ADRENAL GLAND ADENOMA, ADENOMA OF THE ADRENAL CORTEX, ADENOMA OF THE ADRENAL GLAND, ADENOMA, ADRENOCORTICAL , BENIGN, ADENOMA OF ADRENAL GLAND, BENIGN ADRENAL ADENOMA, Adrenal cortical adenoma, Adrenal adenoma, Adrenal adenoma (disorder), Adrenal cortical adenoma (disorder), Adrenal cortical adenoma morphology, adenoma; adrenal, adrenal; adenoma, Adrenal cortical adenoma, NOS, Adrenal cortical adenoma (morphologic abnormality), Adenoma, Adrenal Cortical, Adrenocortical Adenoma, Adenoma of Adrenal Cortex, Adenoma of the Adrenal Cortex, Adrenal Cortex Adenoma, Adenoma;adrenal
Italian Adenoma della ghiandola surrenale, Adenoma corticosurrenale
French Adénome surrénal, ADENOME SURRENAL, Adénome surrénalien, Adénome corticosurrénalien, Adénome cortico-surrénalien
German Nebennierenadenom, Adenom der Nebenniere, Adenom, Nebennierenrinden-
Spanish Adenoma de la Corteza Suprarrenal, Adenoma Corticosuprarrenal, adenoma de la corteza suprarrenal (anomalía morfológica), [M]adenoma corticosuprarrenal, SAI (anomalía morfológica), [M]adenoma corticosuprarrenal, SAI, [M]adenoma cortical suprarrenal, SAI, adenoma de corteza suprarrenal, no clasificado como subtipo en la Clasificación Internacional de Enfermedades para Oncología, adenoma de corteza suprarrenal, no clasificado como subtipo en la Clasificación Internacional de Enfermedades para Oncología (anomalía morfológica), adenoma de la corteza suprarrenal, no clasificado como subtipo en CIE-O, adenoma de la corteza suprarrenal, no clasificado como subtipo en CIE-O (anomalía morfológica), adenoma de corteza suprarrenal, adenoma de la corteza suprarrenal, adenoma corticosuprarrenal (trastorno), adenoma corticosuprarrenal, adenoma suprarrenal (trastorno), adenoma suprarrenal, Adenoma de glándulas suprarrenales
Japanese 副腎腺腫, フクジンセンシュ, コン病, 副腎皮質腺腫, Conn病, 腺腫-副腎皮質
Swedish Binjurebarksadenom
Czech adenom kůry nadledviny, adenom adrenální kortikální, Adenom nadledvin, Adrenální adenom, adenom kůry nadledvin, adrenokortikální adenom
Finnish Lisämunuaisen kuorikerroksen adenooma
Russian ADENOMA ADRENOKORTIKAL'NAIA, ADRENOKORTIKAL'NAIA ADENOMA, ADENOMA ADRENOKORTIKOKLETOCHNAIA, АДЕНОМА АДРЕНОКОРТИКОКЛЕТОЧНАЯ, АДЕНОМА АДРЕНОКОРТИКАЛЬНАЯ, АДРЕНОКОРТИКАЛЬНАЯ АДЕНОМА
Portuguese ADENOMA SUPRARRENAL, Adenoma supra-renal, Adenoma do Córtex Supra-Renal, Adenoma Adrenocortical
Polish Gruczolak kory nadnerczy
Hungarian Mellékvese-adenoma, Jóindulatú mellékvese-mirigydaganat
Norwegian Binyrebarkadenom, Adrenokortikalt adenom
Dutch adenoom; bijnier, bijnier; adenoom, bijnieradenoom, Adenoom, adrenocorticaal, Adrenocorticaal adenoom, Bijnierschorsadenoom, Conn, ziekte van

Ontology: Adrenal mass (C0342500)

Concepts Disease or Syndrome (T047)
SnomedCT 237783006
Italian Massa surrenale
Japanese 副腎腫瘤, フクジンシュリュウ
Czech Rezistence nadledviny
English Mass of adrenal gland, Adrenal mass (disorder), Mass of adrenal gland (finding), adrenal masses, mass adrenal, adrenal mass, Adrenal gland mass, Adrenal mass, Adrenal Mass, Mass;adrenal
Spanish masa suprarrenal (trastorno), masa adrenal, masa suprarrenal (hallazgo), masa suprarrenal, Masa suprarrenal
Hungarian Mellékvese térfoglaló folyamata
Portuguese Massa suprarrenal
Dutch bijnier gezwel
French Masse de la glande surrénale
German Raumforderung der Nebenniere

Ontology: Adrenal incidentaloma (C2609247)

Concepts Neoplastic Process (T191)
MSH C538238
Spanish Incidentaloma adrenal
Portuguese Incidentaloma supra-renal
Dutch bijnierincidentaloom
Italian Incidentaloma surrenalico
French Incidentalome surrénalien
German Inzidentalom der Nebenniere
Czech Nadledvinová incidentaloma
Japanese 副腎偶発腫, フクジングウハツシュ
English Adrenal incidentaloma
Hungarian Mellékvese incidentaloma