Case Report

401

A Functioning Adrenocortical Oncocytoma

Woo Seok Oh Jae Wook Chung Joon Beom Kwon Tae Gyun Kwon Jeong Sik Kim1 Gil Sook Yoon1

From the Departments of Urology and 1Pathology School of Medicine Kyungpook National University Daegu Korea

Adrenocortical oncocytomas are exceptionally rare and most are benign and nonfunctioning Only 3 cases of adrenal oncocytomas have been reported in the Korean literature and all of them were nonfunctioning Herein we report a case of a functioning adrenocortical oncocytoma in a 49-year-old man who presented with Cushing syndrome (Korean J Urol 200950401-403)985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103Key Words Oxyphilic adenoma Cushing syndrome

Korean Journal of Urology Vol 50 No 4 401-403 April 2009

DOI 104111kju2009504401

ReceivedOctober 23 2008AcceptedNovember 5 2008

Correspondence to Tae Gyun KwonDepartment of Urology Kyungpook National University Hospital 50 Samdeok2-ga Jung-gu Daegu 700-721 KoreaTEL 053-420-5841FAX 053-421-9618E-mail tgkwonknuackr

The Korean Urological Association 2009

Fig 1 Enhanced abdominopelvic computed tomography A 77 cm mass enclosed by a capsule was found on the left adrenal gland (A)

Some necrotic tissue was found in the mass (B)

An oncocytoma is a benign tumor consisting of oncocytes in

which the cytoplasm became eosinophilic due to the accumula-

tion of abnormal mitochondria Oncocytomas develop in various

organs and are frequently found in the salivary gland the kidney

the thyroid gland the parathyroid gland and the hypophysis1

However adrenocortical oncocytomas have rarely been reported

just 25 cases and 3 cases have been reported in the foreign

literature and domestic literature respectively2-4 Most of the

oncocytomas reported in the literature were nonfunctioning

tumors and were incidentally found during a health examination

In the present case the authors found a left adrenal tumor

in a 49-year-old male who visited the hospital as a result of

Cushing syndrome and underwent an adrenalectomy A histo-

pathologic examination was performed after the operation and

as a result the case was judged to be an oncocytoma Here

we report the case along with a bibliography

CASE REPORT

A 49-year-old male visited the hospital because he had

gained 2 kg over 4 months and had symptoms of truncal

obesity and also facial edema that had progressed for 2 months

402 Korean Journal of Urology vol 50 401-403 April 2009

Fig 5 Electron microscopy Electron dense inclusion and closely

packed mitochondria were found Some destructed mitochondria

with Golgi complex were found (x4000)

Fig 2 Whole-body positron emission tomographycomputed to-

mography (PETCT) scan A 77 cm hypermetabolic mass lesion

with fluorodeoxyglucose (FDG) uptake was found in the left

adrenal gland

Fig 3 The tumor was grossly well circumscribed with a dark

brown color

Fig 4 Typical structure of an oncocytoma with abundant eosino-

philic and granular cytoplasm Nuclear atypia with enlarged nuclei

was found (HampE x200)

There were no abnormalities on the results of a blood test a

serum electrolyte test and a biochemical test Twenty-four hour

urinary free cortisol (UFC) was increased by 72218 g (58-403

g) per day and did not decrease with the low-dose dexametha-

sone suppression test Cushing syndrome was therefore diag-

nosed An abdominal computed tomography (CT) scan was

performed to locate the lesion and a 77 cm tumor accom-

panied by internal necrosis was observed on the left adrenal

gland (Fig 1) Positron emission tomography (PET) and CT

were performed to ascertain whether the tumor was malignant

and was metastasized to other organs As a result a hyper-

trophy was observed of the left adrenal lump but lesions

suspicious of metastases were not found (Fig 2) In the results

of several tests performed to assess adrenal function blood

epinephrine norepinephrine vanillylmandelic acid and total

metanephrine were within normal levels

We diagnosed the case as Cushing syndrome caused by the

adrenal tumor and performed laparotomy and adrenalectomy

because the malignant tumor could not be excluded clinically

The tumor did not seem to be metastasized to other organs at

the time of the operation and 7 days after undergoing the

operation the patient was discharged without intraoperative or

Woo Seok Oh et alA Functioning Adrenocortical Oncocytoma 403

postoperative complications

The extracted lump weighed 260 g and measured 100x75x47

cm At the incisal surface the tumor was yellowish and was

surrounded by a well-defined capsule on the inside necrosis and

hemorrhage were partially observed (Fig 3) Light microscopy

showed that the tumor was surrounded by a fibrous pseudo-

capsule and adrenocortical necrosis was seen in patches Also

the tumor tissue consisted of polygonal cells having abundant

eosinophilic cytoplasm in a regular form Most nuclei were

similar in size but some were atypically large (Fig 4) Electron

microscopy showed that the oncocytic cytoplasm was filled with

a great number of mitochondria also some lysosomes Golgi

bodies small lipid particles and glycogen particles were observed

as is usual with oncocytomas Likewise inclusion bodies of high

electron density were observed in mitochondria (Fig 5)

DISCUSSION

An oncocytoma is a tumor consisting of polygonal cells that

abundantly have eosinophilic granule cells ie oncocytes The

oncocyte is defined as a cell in which abnormal mitochondria

which exclude other structures accumulate Mitochondrial

accumulation and tumorigenesis have not been clarified yet but

there is a possibility that it is related to the inflammatory re-

sponse regression or cellular aging Many scientists infer that

mitochondrial accumulation compensatorily causes functional

loss Oncocytomas develop in various organs but are especially

frequent in epithelial cells of high metabolic activity Namely

they mostly develop in the salivary gland the kidney the

thyroid gland the parathyroid gland and the hypophysis1

Adrenocortical oncocytomas have rarely been reported just

25 cases and 4 cases inclusive of the present case have been

reported in the foreign literature and the domestic literature

respectively2-4 With regard to functioning oncocytomas no

cases have been reported in the nation Even in other countries

just 5 cases have been reported5-9 namely one case where

androgenic hormone was secreted in a female one case where

interleukin-6 was produced and 3 cases of Cushing syndrome

The present case indicates Cushing syndrome accompanied by

truncal obesity and facial edema

In most cases the adrenal tumor is incidentally found in the

process of a health examination and after that the patient visits

a urologist In this case however the patient visited the

hospital because of symptoms of Cushing syndrome and the

adrenal tumor was found in process of the examination The

possibility of a metastatic tumor was ruled out because primary

lesions were not observed on CT or PET and the case was

diagnosed as Cushing syndrome by assessing adrenal function

The light microscopy and electron microscopy performed

after the operation showed typical characteristics of oncocy-

tomas as reported elsewhere910 The cellular structure of the

oncocytoma was compared with other adrenal tumors by using

an electron microscope In the case of the pheochromocytoma

a number of granules were bound to the cytomembrane of high

electron density in neurosecretory granules and tumor cells

Benign adrenal adenomas are not filled with mitochondria

Such characteristics distinguish the oncocytoma from others

Nonfunctioning adrenal tumors which are incidentally found

are open to dispute On the other hand surgical operations

should be performed on functioning adrenal tumors In addition

medical scientists should further study functioning oncocytomas

and be more aware of them in consideration of their rareness

REFERENCES

1 Chang A Harawi SJ Oncocytes oncocytosis and oncocytic

tumors Pathol Annu 199227263-304

2 Lee SJ Lee HG Park CY Jeong IK Hong EG Oh GW et

al A case of adrenocortical oncocytoma J Korean Endocrinol

20041982-9

3 Lin BT Bonsib SM Mierau GW Weiss LM Medeiros LJ

Oncocytic adrenocortical neoplasms a report of seven cases

and review of the literature Am J Surg Pathol 199822603-14

4 Chang HS Sohn JC Park CH Kim CI Kwon SY

Adrenocortical oncocytoma Korean J Urol 200748103-6

5 Geramizadeh B Norouzzadeh B Bolandparvaz S Sefidbakht

S Functioning adrenocortical oncocytoma a case report and

review of literature Indian J Pathol Microbiol 200851237-9

6 Akatsu T Kameyama K Araki K Ashizawa T Wakabayashi

G Kitajima M Functioning adrenocortical oncocytoma the

first documented case producing interleukin-6 and review of

the literature J Endocrinol Invest 20083168-73

7 Gołkowski F Buziak-Bereza M Huszno B Bałdys-Waligoacuterska

A Stefańska A Budzyński A et al The unique case of

adrenocortical malignant and functioning oncocytic tumour

Exp Clin Endocrinol Diabetes 2007115401-4

8 Xiao GQ Pertsemlidis DS Unger PD Functioning adrenocor-

tical oncocytoma a case report and review of the literature

Ann Diagn Pathol 20059295-7

9 Erlandson RA Reuter VE Oncocytic adrenal cortical adeno-

ma Ultrastruct Pathol 199115539-47

10 El-Naggar AK Evans DB Mackay B Oncocytic adrenal

cortical carcinoma Ultrastruct Pathol 199115549-56

402 Korean Journal of Urology vol 50 401-403 April 2009

Fig 5 Electron microscopy Electron dense inclusion and closely

packed mitochondria were found Some destructed mitochondria

with Golgi complex were found (x4000)

Fig 2 Whole-body positron emission tomographycomputed to-

mography (PETCT) scan A 77 cm hypermetabolic mass lesion

with fluorodeoxyglucose (FDG) uptake was found in the left

adrenal gland

Fig 3 The tumor was grossly well circumscribed with a dark

brown color

Fig 4 Typical structure of an oncocytoma with abundant eosino-

philic and granular cytoplasm Nuclear atypia with enlarged nuclei

was found (HampE x200)

There were no abnormalities on the results of a blood test a

serum electrolyte test and a biochemical test Twenty-four hour

urinary free cortisol (UFC) was increased by 72218 g (58-403

g) per day and did not decrease with the low-dose dexametha-

sone suppression test Cushing syndrome was therefore diag-

nosed An abdominal computed tomography (CT) scan was

performed to locate the lesion and a 77 cm tumor accom-

panied by internal necrosis was observed on the left adrenal

gland (Fig 1) Positron emission tomography (PET) and CT

were performed to ascertain whether the tumor was malignant

and was metastasized to other organs As a result a hyper-

trophy was observed of the left adrenal lump but lesions

suspicious of metastases were not found (Fig 2) In the results

of several tests performed to assess adrenal function blood

epinephrine norepinephrine vanillylmandelic acid and total

metanephrine were within normal levels

We diagnosed the case as Cushing syndrome caused by the

adrenal tumor and performed laparotomy and adrenalectomy

because the malignant tumor could not be excluded clinically

The tumor did not seem to be metastasized to other organs at

the time of the operation and 7 days after undergoing the

operation the patient was discharged without intraoperative or

Woo Seok Oh et alA Functioning Adrenocortical Oncocytoma 403

postoperative complications

The extracted lump weighed 260 g and measured 100x75x47

cm At the incisal surface the tumor was yellowish and was

surrounded by a well-defined capsule on the inside necrosis and

hemorrhage were partially observed (Fig 3) Light microscopy

showed that the tumor was surrounded by a fibrous pseudo-

capsule and adrenocortical necrosis was seen in patches Also

the tumor tissue consisted of polygonal cells having abundant

eosinophilic cytoplasm in a regular form Most nuclei were

similar in size but some were atypically large (Fig 4) Electron

microscopy showed that the oncocytic cytoplasm was filled with

a great number of mitochondria also some lysosomes Golgi

bodies small lipid particles and glycogen particles were observed

as is usual with oncocytomas Likewise inclusion bodies of high

electron density were observed in mitochondria (Fig 5)

DISCUSSION

An oncocytoma is a tumor consisting of polygonal cells that

abundantly have eosinophilic granule cells ie oncocytes The

oncocyte is defined as a cell in which abnormal mitochondria

which exclude other structures accumulate Mitochondrial

accumulation and tumorigenesis have not been clarified yet but

there is a possibility that it is related to the inflammatory re-

sponse regression or cellular aging Many scientists infer that

mitochondrial accumulation compensatorily causes functional

loss Oncocytomas develop in various organs but are especially

frequent in epithelial cells of high metabolic activity Namely

they mostly develop in the salivary gland the kidney the

thyroid gland the parathyroid gland and the hypophysis1

Adrenocortical oncocytomas have rarely been reported just

25 cases and 4 cases inclusive of the present case have been

reported in the foreign literature and the domestic literature

respectively2-4 With regard to functioning oncocytomas no

cases have been reported in the nation Even in other countries

just 5 cases have been reported5-9 namely one case where

androgenic hormone was secreted in a female one case where

interleukin-6 was produced and 3 cases of Cushing syndrome

The present case indicates Cushing syndrome accompanied by

truncal obesity and facial edema

In most cases the adrenal tumor is incidentally found in the

process of a health examination and after that the patient visits

a urologist In this case however the patient visited the

hospital because of symptoms of Cushing syndrome and the

adrenal tumor was found in process of the examination The

possibility of a metastatic tumor was ruled out because primary

lesions were not observed on CT or PET and the case was

diagnosed as Cushing syndrome by assessing adrenal function

The light microscopy and electron microscopy performed

after the operation showed typical characteristics of oncocy-

tomas as reported elsewhere910 The cellular structure of the

oncocytoma was compared with other adrenal tumors by using

an electron microscope In the case of the pheochromocytoma

a number of granules were bound to the cytomembrane of high

electron density in neurosecretory granules and tumor cells

Benign adrenal adenomas are not filled with mitochondria

Such characteristics distinguish the oncocytoma from others

Nonfunctioning adrenal tumors which are incidentally found

are open to dispute On the other hand surgical operations

should be performed on functioning adrenal tumors In addition

medical scientists should further study functioning oncocytomas

and be more aware of them in consideration of their rareness

REFERENCES

1 Chang A Harawi SJ Oncocytes oncocytosis and oncocytic

tumors Pathol Annu 199227263-304

2 Lee SJ Lee HG Park CY Jeong IK Hong EG Oh GW et

al A case of adrenocortical oncocytoma J Korean Endocrinol

20041982-9

3 Lin BT Bonsib SM Mierau GW Weiss LM Medeiros LJ

Oncocytic adrenocortical neoplasms a report of seven cases

and review of the literature Am J Surg Pathol 199822603-14

4 Chang HS Sohn JC Park CH Kim CI Kwon SY

Adrenocortical oncocytoma Korean J Urol 200748103-6

5 Geramizadeh B Norouzzadeh B Bolandparvaz S Sefidbakht

S Functioning adrenocortical oncocytoma a case report and

review of literature Indian J Pathol Microbiol 200851237-9

6 Akatsu T Kameyama K Araki K Ashizawa T Wakabayashi

G Kitajima M Functioning adrenocortical oncocytoma the

first documented case producing interleukin-6 and review of

the literature J Endocrinol Invest 20083168-73

7 Gołkowski F Buziak-Bereza M Huszno B Bałdys-Waligoacuterska

A Stefańska A Budzyński A et al The unique case of

adrenocortical malignant and functioning oncocytic tumour

Exp Clin Endocrinol Diabetes 2007115401-4

8 Xiao GQ Pertsemlidis DS Unger PD Functioning adrenocor-

tical oncocytoma a case report and review of the literature

Ann Diagn Pathol 20059295-7

9 Erlandson RA Reuter VE Oncocytic adrenal cortical adeno-

ma Ultrastruct Pathol 199115539-47

10 El-Naggar AK Evans DB Mackay B Oncocytic adrenal

cortical carcinoma Ultrastruct Pathol 199115549-56

Woo Seok Oh et alA Functioning Adrenocortical Oncocytoma 403

postoperative complications

The extracted lump weighed 260 g and measured 100x75x47

cm At the incisal surface the tumor was yellowish and was

surrounded by a well-defined capsule on the inside necrosis and

hemorrhage were partially observed (Fig 3) Light microscopy

showed that the tumor was surrounded by a fibrous pseudo-

capsule and adrenocortical necrosis was seen in patches Also

the tumor tissue consisted of polygonal cells having abundant

eosinophilic cytoplasm in a regular form Most nuclei were

similar in size but some were atypically large (Fig 4) Electron

microscopy showed that the oncocytic cytoplasm was filled with

a great number of mitochondria also some lysosomes Golgi

bodies small lipid particles and glycogen particles were observed

as is usual with oncocytomas Likewise inclusion bodies of high

electron density were observed in mitochondria (Fig 5)

DISCUSSION

An oncocytoma is a tumor consisting of polygonal cells that

abundantly have eosinophilic granule cells ie oncocytes The

oncocyte is defined as a cell in which abnormal mitochondria

which exclude other structures accumulate Mitochondrial

accumulation and tumorigenesis have not been clarified yet but

there is a possibility that it is related to the inflammatory re-

sponse regression or cellular aging Many scientists infer that

mitochondrial accumulation compensatorily causes functional

loss Oncocytomas develop in various organs but are especially

frequent in epithelial cells of high metabolic activity Namely

they mostly develop in the salivary gland the kidney the

thyroid gland the parathyroid gland and the hypophysis1

Adrenocortical oncocytomas have rarely been reported just

25 cases and 4 cases inclusive of the present case have been

reported in the foreign literature and the domestic literature

respectively2-4 With regard to functioning oncocytomas no

cases have been reported in the nation Even in other countries

just 5 cases have been reported5-9 namely one case where

androgenic hormone was secreted in a female one case where

interleukin-6 was produced and 3 cases of Cushing syndrome

The present case indicates Cushing syndrome accompanied by

truncal obesity and facial edema

In most cases the adrenal tumor is incidentally found in the

process of a health examination and after that the patient visits

a urologist In this case however the patient visited the

hospital because of symptoms of Cushing syndrome and the

adrenal tumor was found in process of the examination The

possibility of a metastatic tumor was ruled out because primary

lesions were not observed on CT or PET and the case was

diagnosed as Cushing syndrome by assessing adrenal function

The light microscopy and electron microscopy performed

after the operation showed typical characteristics of oncocy-

tomas as reported elsewhere910 The cellular structure of the

oncocytoma was compared with other adrenal tumors by using

an electron microscope In the case of the pheochromocytoma

a number of granules were bound to the cytomembrane of high

electron density in neurosecretory granules and tumor cells

Benign adrenal adenomas are not filled with mitochondria

Such characteristics distinguish the oncocytoma from others

Nonfunctioning adrenal tumors which are incidentally found

are open to dispute On the other hand surgical operations

should be performed on functioning adrenal tumors In addition

medical scientists should further study functioning oncocytomas

and be more aware of them in consideration of their rareness

REFERENCES

1 Chang A Harawi SJ Oncocytes oncocytosis and oncocytic

tumors Pathol Annu 199227263-304

2 Lee SJ Lee HG Park CY Jeong IK Hong EG Oh GW et

al A case of adrenocortical oncocytoma J Korean Endocrinol

20041982-9

3 Lin BT Bonsib SM Mierau GW Weiss LM Medeiros LJ

Oncocytic adrenocortical neoplasms a report of seven cases

and review of the literature Am J Surg Pathol 199822603-14

4 Chang HS Sohn JC Park CH Kim CI Kwon SY

Adrenocortical oncocytoma Korean J Urol 200748103-6

5 Geramizadeh B Norouzzadeh B Bolandparvaz S Sefidbakht

S Functioning adrenocortical oncocytoma a case report and

review of literature Indian J Pathol Microbiol 200851237-9

6 Akatsu T Kameyama K Araki K Ashizawa T Wakabayashi

G Kitajima M Functioning adrenocortical oncocytoma the

first documented case producing interleukin-6 and review of

the literature J Endocrinol Invest 20083168-73

7 Gołkowski F Buziak-Bereza M Huszno B Bałdys-Waligoacuterska

A Stefańska A Budzyński A et al The unique case of

adrenocortical malignant and functioning oncocytic tumour

Exp Clin Endocrinol Diabetes 2007115401-4

8 Xiao GQ Pertsemlidis DS Unger PD Functioning adrenocor-

tical oncocytoma a case report and review of the literature

Ann Diagn Pathol 20059295-7

9 Erlandson RA Reuter VE Oncocytic adrenal cortical adeno-

ma Ultrastruct Pathol 199115539-47

10 El-Naggar AK Evans DB Mackay B Oncocytic adrenal

cortical carcinoma Ultrastruct Pathol 199115549-56