Case Report

1258

Aggressive Angiomyxoma as the Cause of Lower Urinary Tract Symptoms

Sang Hyub Lee Youn Wha Kim1 Sung-Goo ChangFrom the Departments of Urology and 1Pathology School of Medicine Kyung Hee University Seoul Korea

Aggressive angiomyxoma (AAM) is a rare benign tumor It usually involves the connective tissue of the perineal regions in women of reproductive age In this report we present a case of AAM in a 66-year-old female which presented itself as a retrovesical tumor on pelvic magnetic resonance imaging and caused lower urinary tract symptoms The tumor was resected en bloc and the patientrsquos voiding symptoms disappeared (Korean J Urol 2009501258-1261)985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103985103Key Words Myxoma Neoplasms Pelvic neoplasms

Korean Journal of Urology Vol 50 No 12 1258-1261 December 2009

DOI 104111kju200950121258ReceivedMay 29 2009AcceptedNovember 27 2009

Correspondence to Sung-Goo ChangDepartment of Urology Kyung Hee University Medical Center1 Hoegi-dong Dongdaemun-gu Seoul 130-702 KoreaTEL 02-958-8533FAX 02-959-6048E-mail sgchangkhuackr

The Korean Urological Association 2009

　Aggressive angiomyxoma (AAM) usually occurs in the geni-

tal and perineal area of female patients and most commonly

in the third to fifth decades of life [1] A retrovesical tumor

is defined as ldquoa tumor arising from retrovesical tissue excluding

the pelvic organs such as rectum bladder prostate seminal

vesicle vagina or uterusrdquo and may or may not cause lower

urinary tract symptoms [2] This report discusses a rare case

of AAM that caused lower urinary tract symptoms and

presented itself as a retrovesical tumor on pelvic magnetic

resonance imaging (MRI)

CASE REPORT

　A 66-year-old female patient underwent abdominal pelvis

ultrasonography (A-P sono) for a routine check The A-P sono

showed a mass between the urinary bladder and the vagina For

further evaluation of this mass the patient visited the Depart-

ment of Urology She presented with frequency of urination and

nocturia of three times per night Her voiding diary showed that

her functional bladder capacity was less than 200 ml Upon

physical examination her abdomen was soft and movable and

there was no tenderness The mass was palpable through the

vagina and it was soft and round The laboratory findings were

within normal limits and her tumor markers such as CA 19-9

AFP and CEA were within normal ranges Transvaginal

ultrasonography (TVUS) and pelvic MRI were performed

TVUS revealed a 51x47x34 cm sized homogeneous mass that

was compressing the urinary bladder (Fig 1A B) On the

pelvic MRI the tumor was located in the retrovesical space and

it was thought to be arising from the retrovesical tissue such

as the bladder vagina or uterus However we could not rule

out that the tumor might have originated from the urethra On

the T1-weighted image the tumor was of homogeneous and

low intensity similar to the image of the muscles On the

T2-weighted image the mass was heterogeneous and of

intermediate intensity (Fig 1C D) The tumor was thought to

be a leiomyoma a rhabdomyosarcoma or a neurogenic tumor

as suggested by these MRI findings

　In the operation field the tumor was adhered to the posterior

bladder wall However it was easily separated from the bladder

wall and was resected en bloc The resected tumor was 55x4x3

cm in size Grossly the tumor had a soft smooth and elastic

surface (Fig 2) The cut surface showed whitish-yellow homo-

geneous lesions Microscopically the mass was made up of

rather well-demarcated tumor tissues which showed low

cellularity of relatively uniform small satellite and spindly

cells that were set in a loosely collagenous myxoid matrix with

scattered vessels of varying caliber The tumor cells had scant

pale eosinophilic cytoplasm with poorly defined borders and

relatively bland nuclei with open chromatin and a single small

Sang Hyub Lee et alAggressive Angiomyxoma 1259

Fig 1 (A B) Transvaginal ultra-

sonography showing a huge tumor

compressing the urinary bladder

(C) T1-weighted magnetic reso-

nance image (MRI) showing a mass

with low signal intensity posterior

to the urinary bladder (D) T2-

weighted sagittal MRI showing a

mass with intermediate signal inten-

sity

Fig 2 The gross findings are a rather well-circumscribed gray-

white mass with a soft smooth and elastic surface

nucleoli Multinucleated giant cells were rarely observed

Mitotic figures were infrequent On the basis of these histologic

findings this case was diagnosed as AAM (Fig 3) Immuno-

histochemically the tumor cells showed diffuse staining for

vimentin desmin estrogen and progesterone receptors and

focal staining for actin (Fig 4) After the surgery the patientrsquos

nocturia disappeared and her functional bladder capacity

increased to 350 ml At 1 year of follow-up the patient was

free from recurrence

DISCUSSION

　AAM is a rare and benign tumor that involves the connective

tissue of the perineal regions in women of reproductive age [1]

Because the patientrsquos age was 66 years old this case occurred

much later than in an average case In Korea several cases of

AAM have been reported However only one case of AAM

after menopause has been reported [3]

　AAM was first described by Steeper and Rosai in 1983 [4]

They described nine cases of soft tissue tumor in the female

genitalia and named it aggressive angiomyxoma Since then

about 200 cases of this tumor have been reported Although

some male cases have been reported [5] almost all of the

reported tumors arose from the perineum in young female

patients Only a few cases of AAM have been discovered in

the retrovesical area in older women

　Preoperative diagnosis of tumors in this region is usually

based on imaging studies but such tumors seldom get diag-

nosed as AAM The MR features of AAMs have been

described as isointense or low signal intensity on T1-weighted

images and high signal intensity on T2-weighted images The

voluted pattern of signal intensity on the T2-weighted images

is reported as a typical finding in AAMs The high signal on

1260 Korean Journal of Urology vol 50 1258-1261 December 2009

Fig 3 Pathologic findings show dispersed spindle-shaped cells and thick-walled blood vessels with a myxoid stroma [(A) x100 (B) x400]

Fig 4 Immunohistochemical analyses show positive results for (A)

estrogen receptor (B) desmin and (C) progesterone receptor

the T2-weighted MR image is likely to be due to the high water

content and myxoid matrix of the tumor [6] In our case

however the tumor did not show a low signal intensity on the

T1-weighted images and showed intermediate signal intensity

on the T2-weighted images

　AAM is derived from myofibroblasts as a phenotypic variant

Sang Hyub Lee et alAggressive Angiomyxoma 1261

of the basic fibroblast with cytoskeletal adaptation appropriate

to situations such as wound healing The locally invasive

character and induction of associated neovascularity are not

surprising in a neoplasm of this histogenesis [7]

　One of the most important findings for AAM are the

immunohistochemical analyses AAM must be histologically

differentiated from other benign and malignant myxoid neo-

plasms such as angiofibroblastoma cutaneous myxoma my-

xoid neurofibroma myxoid leiomyoma pelvic fibromatosis

myxoid liposarcoma and low-grade myxoid malignant fibrous

histiocytoma For differential diagnosis the reactivity for

desmin smooth muscle actin muscle-specific actin vimentin

CD34 S100 protein and estrogen and progestin receptors must

be confirmed [18] Reactivity for estrogen and progesterone

receptors suggests that this tumor may be a hormone-responsive

neoplasm

　According to previous studies local recurrence of this tumor

is common with a recurrence rate of 50-70 even if the whole

mass is resected en bloc [9] The tumor was therefore termed

ldquoaggressiverdquo angiomyxoma Most recurrences of AAM have

occurred within the first 3 years of the initial diagnosis [10]

However one case of AAM that recurred 14 years after the

en-bloc resection has been reported so it is necessary to

maintain long-term follow-up and to carefully monitor with

imaging studies [8] In our case the follow-up period has been

only 1 year so it is too early to predict future recurrence

　In conclusion this case demonstrates that an AAM may

occur as a retrovesical tumor and may cause lower urinary tract

symptoms Therefore AAM should be recognized as a dif-

ferential diagnosis in a woman presenting with a retrovesical

tumor

ACKNOWLEDGEMENT

　This work was supported by a Korea Science and Engi-

neering Foundation (KOSEF) grant funded by the Korea

Government (MOST) [No 20090091346]

REFERENCES

1 Fetsch JF Laskin WB Lefkowitz M Kindblom LG Meis-

Kindblom JM Aggressive angiomyxoma a clinicopathologic

study of 29 female patients Cancer 19967879-90

2 Hatano K Tsujimoto Y Ichimaru N Miyagawa Y Nonomura

N Okuyama A Rare case of aggressive angiomyxoma pre-

senting as a retrovesical tumor Int J Urol 2006131012-4

3 Lee CJ Yun GB Kim HY Kim WG Kim SH Park ED et

al Aggressive angiomyxoma of the vagina after menopause

Korean J Gynecol Oncol Colposc 200314167-71

4 Steeper TA Rosai J Aggressive angiomyxoma of the female

pelvis and perineum Report of nine cases of a distinctive type

of gynecologic soft-tissue neoplasm Am J Surg Pathol 19837

463-75

5 Kim TH Kim YS Myung SC Shin HO Lee TJ Yoo SM

et al An aggressive rapidly increasing angiomyxoma of the

scrotum Korean J Urol 200647553-5

6 Jeyadevan NN Sohaib SA Thomas JM Jeyarajah A She-

pherd JH Fisher C Imaging features of aggressive angio-

myxoma Clin Radiol 200358157-62

7 Smith HO Worrell RV Smith AY Dorin MH Rosenberg RD

Bartow SA Aggressive angiomyxoma of the female pelvis and

perineum review of the literature Gynecol Oncol 199142

79-85

8 Smirniotis V Kondi-Pafiti A Theodoraki K Kostopanagiotou

G Liapis A Kourias E Aggressive angiomyxoma of the

pelvis a clinicopathologic study of a case Clin Exp Obstet

Gynecol 199724209-11

9 Stephenson BM Williams EV Sturdy DE Vellacott KD

Aggressive angiomyxoma of the perineum and pelvis Br J

Surg 1992791181

10 Chan YM Hon E Ngai SW Ng TY Wong LC Aggressive

angiomyxoma in females Is radical resection the only option

Acta Obstet Gynecol Scand 200079216-20

Sang Hyub Lee et alAggressive Angiomyxoma 1259

Fig 1 (A B) Transvaginal ultra-

sonography showing a huge tumor

compressing the urinary bladder

(C) T1-weighted magnetic reso-

nance image (MRI) showing a mass

with low signal intensity posterior

to the urinary bladder (D) T2-

weighted sagittal MRI showing a

mass with intermediate signal inten-

sity

Fig 2 The gross findings are a rather well-circumscribed gray-

white mass with a soft smooth and elastic surface

nucleoli Multinucleated giant cells were rarely observed

Mitotic figures were infrequent On the basis of these histologic

findings this case was diagnosed as AAM (Fig 3) Immuno-

histochemically the tumor cells showed diffuse staining for

vimentin desmin estrogen and progesterone receptors and

focal staining for actin (Fig 4) After the surgery the patientrsquos

nocturia disappeared and her functional bladder capacity

increased to 350 ml At 1 year of follow-up the patient was

free from recurrence

DISCUSSION

　AAM is a rare and benign tumor that involves the connective

tissue of the perineal regions in women of reproductive age [1]

Because the patientrsquos age was 66 years old this case occurred

much later than in an average case In Korea several cases of

AAM have been reported However only one case of AAM

after menopause has been reported [3]

　AAM was first described by Steeper and Rosai in 1983 [4]

They described nine cases of soft tissue tumor in the female

genitalia and named it aggressive angiomyxoma Since then

about 200 cases of this tumor have been reported Although

some male cases have been reported [5] almost all of the

reported tumors arose from the perineum in young female

patients Only a few cases of AAM have been discovered in

the retrovesical area in older women

　Preoperative diagnosis of tumors in this region is usually

based on imaging studies but such tumors seldom get diag-

nosed as AAM The MR features of AAMs have been

described as isointense or low signal intensity on T1-weighted

images and high signal intensity on T2-weighted images The

voluted pattern of signal intensity on the T2-weighted images

is reported as a typical finding in AAMs The high signal on

1260 Korean Journal of Urology vol 50 1258-1261 December 2009

Fig 3 Pathologic findings show dispersed spindle-shaped cells and thick-walled blood vessels with a myxoid stroma [(A) x100 (B) x400]

Fig 4 Immunohistochemical analyses show positive results for (A)

estrogen receptor (B) desmin and (C) progesterone receptor

the T2-weighted MR image is likely to be due to the high water

content and myxoid matrix of the tumor [6] In our case

however the tumor did not show a low signal intensity on the

T1-weighted images and showed intermediate signal intensity

on the T2-weighted images

　AAM is derived from myofibroblasts as a phenotypic variant

Sang Hyub Lee et alAggressive Angiomyxoma 1261

of the basic fibroblast with cytoskeletal adaptation appropriate

to situations such as wound healing The locally invasive

character and induction of associated neovascularity are not

surprising in a neoplasm of this histogenesis [7]

　One of the most important findings for AAM are the

immunohistochemical analyses AAM must be histologically

differentiated from other benign and malignant myxoid neo-

plasms such as angiofibroblastoma cutaneous myxoma my-

xoid neurofibroma myxoid leiomyoma pelvic fibromatosis

myxoid liposarcoma and low-grade myxoid malignant fibrous

histiocytoma For differential diagnosis the reactivity for

desmin smooth muscle actin muscle-specific actin vimentin

CD34 S100 protein and estrogen and progestin receptors must

be confirmed [18] Reactivity for estrogen and progesterone

receptors suggests that this tumor may be a hormone-responsive

neoplasm

　According to previous studies local recurrence of this tumor

is common with a recurrence rate of 50-70 even if the whole

mass is resected en bloc [9] The tumor was therefore termed

ldquoaggressiverdquo angiomyxoma Most recurrences of AAM have

occurred within the first 3 years of the initial diagnosis [10]

However one case of AAM that recurred 14 years after the

en-bloc resection has been reported so it is necessary to

maintain long-term follow-up and to carefully monitor with

imaging studies [8] In our case the follow-up period has been

only 1 year so it is too early to predict future recurrence

　In conclusion this case demonstrates that an AAM may

occur as a retrovesical tumor and may cause lower urinary tract

symptoms Therefore AAM should be recognized as a dif-

ferential diagnosis in a woman presenting with a retrovesical

tumor

ACKNOWLEDGEMENT

　This work was supported by a Korea Science and Engi-

neering Foundation (KOSEF) grant funded by the Korea

Government (MOST) [No 20090091346]

REFERENCES

1 Fetsch JF Laskin WB Lefkowitz M Kindblom LG Meis-

Kindblom JM Aggressive angiomyxoma a clinicopathologic

study of 29 female patients Cancer 19967879-90

2 Hatano K Tsujimoto Y Ichimaru N Miyagawa Y Nonomura

N Okuyama A Rare case of aggressive angiomyxoma pre-

senting as a retrovesical tumor Int J Urol 2006131012-4

3 Lee CJ Yun GB Kim HY Kim WG Kim SH Park ED et

al Aggressive angiomyxoma of the vagina after menopause

Korean J Gynecol Oncol Colposc 200314167-71

4 Steeper TA Rosai J Aggressive angiomyxoma of the female

pelvis and perineum Report of nine cases of a distinctive type

of gynecologic soft-tissue neoplasm Am J Surg Pathol 19837

463-75

5 Kim TH Kim YS Myung SC Shin HO Lee TJ Yoo SM

et al An aggressive rapidly increasing angiomyxoma of the

scrotum Korean J Urol 200647553-5

6 Jeyadevan NN Sohaib SA Thomas JM Jeyarajah A She-

pherd JH Fisher C Imaging features of aggressive angio-

myxoma Clin Radiol 200358157-62

7 Smith HO Worrell RV Smith AY Dorin MH Rosenberg RD

Bartow SA Aggressive angiomyxoma of the female pelvis and

perineum review of the literature Gynecol Oncol 199142

79-85

8 Smirniotis V Kondi-Pafiti A Theodoraki K Kostopanagiotou

G Liapis A Kourias E Aggressive angiomyxoma of the

pelvis a clinicopathologic study of a case Clin Exp Obstet

Gynecol 199724209-11

9 Stephenson BM Williams EV Sturdy DE Vellacott KD

Aggressive angiomyxoma of the perineum and pelvis Br J

Surg 1992791181

10 Chan YM Hon E Ngai SW Ng TY Wong LC Aggressive

angiomyxoma in females Is radical resection the only option

Acta Obstet Gynecol Scand 200079216-20

1260 Korean Journal of Urology vol 50 1258-1261 December 2009

Fig 3 Pathologic findings show dispersed spindle-shaped cells and thick-walled blood vessels with a myxoid stroma [(A) x100 (B) x400]

Fig 4 Immunohistochemical analyses show positive results for (A)

estrogen receptor (B) desmin and (C) progesterone receptor

the T2-weighted MR image is likely to be due to the high water

content and myxoid matrix of the tumor [6] In our case

however the tumor did not show a low signal intensity on the

T1-weighted images and showed intermediate signal intensity

on the T2-weighted images

　AAM is derived from myofibroblasts as a phenotypic variant

Sang Hyub Lee et alAggressive Angiomyxoma 1261

of the basic fibroblast with cytoskeletal adaptation appropriate

to situations such as wound healing The locally invasive

character and induction of associated neovascularity are not

surprising in a neoplasm of this histogenesis [7]

　One of the most important findings for AAM are the

immunohistochemical analyses AAM must be histologically

differentiated from other benign and malignant myxoid neo-

plasms such as angiofibroblastoma cutaneous myxoma my-

xoid neurofibroma myxoid leiomyoma pelvic fibromatosis

myxoid liposarcoma and low-grade myxoid malignant fibrous

histiocytoma For differential diagnosis the reactivity for

desmin smooth muscle actin muscle-specific actin vimentin

CD34 S100 protein and estrogen and progestin receptors must

be confirmed [18] Reactivity for estrogen and progesterone

receptors suggests that this tumor may be a hormone-responsive

neoplasm

　According to previous studies local recurrence of this tumor

is common with a recurrence rate of 50-70 even if the whole

mass is resected en bloc [9] The tumor was therefore termed

ldquoaggressiverdquo angiomyxoma Most recurrences of AAM have

occurred within the first 3 years of the initial diagnosis [10]

However one case of AAM that recurred 14 years after the

en-bloc resection has been reported so it is necessary to

maintain long-term follow-up and to carefully monitor with

imaging studies [8] In our case the follow-up period has been

only 1 year so it is too early to predict future recurrence

　In conclusion this case demonstrates that an AAM may

occur as a retrovesical tumor and may cause lower urinary tract

symptoms Therefore AAM should be recognized as a dif-

ferential diagnosis in a woman presenting with a retrovesical

tumor

ACKNOWLEDGEMENT

　This work was supported by a Korea Science and Engi-

neering Foundation (KOSEF) grant funded by the Korea

Government (MOST) [No 20090091346]

REFERENCES

1 Fetsch JF Laskin WB Lefkowitz M Kindblom LG Meis-

Kindblom JM Aggressive angiomyxoma a clinicopathologic

study of 29 female patients Cancer 19967879-90

2 Hatano K Tsujimoto Y Ichimaru N Miyagawa Y Nonomura

N Okuyama A Rare case of aggressive angiomyxoma pre-

senting as a retrovesical tumor Int J Urol 2006131012-4

3 Lee CJ Yun GB Kim HY Kim WG Kim SH Park ED et

al Aggressive angiomyxoma of the vagina after menopause

Korean J Gynecol Oncol Colposc 200314167-71

4 Steeper TA Rosai J Aggressive angiomyxoma of the female

pelvis and perineum Report of nine cases of a distinctive type

of gynecologic soft-tissue neoplasm Am J Surg Pathol 19837

463-75

5 Kim TH Kim YS Myung SC Shin HO Lee TJ Yoo SM

et al An aggressive rapidly increasing angiomyxoma of the

scrotum Korean J Urol 200647553-5

6 Jeyadevan NN Sohaib SA Thomas JM Jeyarajah A She-

pherd JH Fisher C Imaging features of aggressive angio-

myxoma Clin Radiol 200358157-62

7 Smith HO Worrell RV Smith AY Dorin MH Rosenberg RD

Bartow SA Aggressive angiomyxoma of the female pelvis and

perineum review of the literature Gynecol Oncol 199142

79-85

8 Smirniotis V Kondi-Pafiti A Theodoraki K Kostopanagiotou

G Liapis A Kourias E Aggressive angiomyxoma of the

pelvis a clinicopathologic study of a case Clin Exp Obstet

Gynecol 199724209-11

9 Stephenson BM Williams EV Sturdy DE Vellacott KD

Aggressive angiomyxoma of the perineum and pelvis Br J

Surg 1992791181

10 Chan YM Hon E Ngai SW Ng TY Wong LC Aggressive

angiomyxoma in females Is radical resection the only option

Acta Obstet Gynecol Scand 200079216-20

Sang Hyub Lee et alAggressive Angiomyxoma 1261

of the basic fibroblast with cytoskeletal adaptation appropriate

to situations such as wound healing The locally invasive

character and induction of associated neovascularity are not

surprising in a neoplasm of this histogenesis [7]

　One of the most important findings for AAM are the

immunohistochemical analyses AAM must be histologically

differentiated from other benign and malignant myxoid neo-

plasms such as angiofibroblastoma cutaneous myxoma my-

xoid neurofibroma myxoid leiomyoma pelvic fibromatosis

myxoid liposarcoma and low-grade myxoid malignant fibrous

histiocytoma For differential diagnosis the reactivity for

desmin smooth muscle actin muscle-specific actin vimentin

CD34 S100 protein and estrogen and progestin receptors must

be confirmed [18] Reactivity for estrogen and progesterone

receptors suggests that this tumor may be a hormone-responsive

neoplasm

　According to previous studies local recurrence of this tumor

is common with a recurrence rate of 50-70 even if the whole

mass is resected en bloc [9] The tumor was therefore termed

ldquoaggressiverdquo angiomyxoma Most recurrences of AAM have

occurred within the first 3 years of the initial diagnosis [10]

However one case of AAM that recurred 14 years after the

en-bloc resection has been reported so it is necessary to

maintain long-term follow-up and to carefully monitor with

imaging studies [8] In our case the follow-up period has been

only 1 year so it is too early to predict future recurrence

　In conclusion this case demonstrates that an AAM may

occur as a retrovesical tumor and may cause lower urinary tract

symptoms Therefore AAM should be recognized as a dif-

ferential diagnosis in a woman presenting with a retrovesical

tumor

ACKNOWLEDGEMENT

　This work was supported by a Korea Science and Engi-

neering Foundation (KOSEF) grant funded by the Korea

Government (MOST) [No 20090091346]

REFERENCES

1 Fetsch JF Laskin WB Lefkowitz M Kindblom LG Meis-

Kindblom JM Aggressive angiomyxoma a clinicopathologic

study of 29 female patients Cancer 19967879-90

2 Hatano K Tsujimoto Y Ichimaru N Miyagawa Y Nonomura

N Okuyama A Rare case of aggressive angiomyxoma pre-

senting as a retrovesical tumor Int J Urol 2006131012-4

3 Lee CJ Yun GB Kim HY Kim WG Kim SH Park ED et

al Aggressive angiomyxoma of the vagina after menopause

Korean J Gynecol Oncol Colposc 200314167-71

4 Steeper TA Rosai J Aggressive angiomyxoma of the female

pelvis and perineum Report of nine cases of a distinctive type

of gynecologic soft-tissue neoplasm Am J Surg Pathol 19837

463-75

5 Kim TH Kim YS Myung SC Shin HO Lee TJ Yoo SM

et al An aggressive rapidly increasing angiomyxoma of the

scrotum Korean J Urol 200647553-5

6 Jeyadevan NN Sohaib SA Thomas JM Jeyarajah A She-

pherd JH Fisher C Imaging features of aggressive angio-

myxoma Clin Radiol 200358157-62

7 Smith HO Worrell RV Smith AY Dorin MH Rosenberg RD

Bartow SA Aggressive angiomyxoma of the female pelvis and

perineum review of the literature Gynecol Oncol 199142

79-85

8 Smirniotis V Kondi-Pafiti A Theodoraki K Kostopanagiotou

G Liapis A Kourias E Aggressive angiomyxoma of the

pelvis a clinicopathologic study of a case Clin Exp Obstet

Gynecol 199724209-11

9 Stephenson BM Williams EV Sturdy DE Vellacott KD

Aggressive angiomyxoma of the perineum and pelvis Br J

Surg 1992791181

10 Chan YM Hon E Ngai SW Ng TY Wong LC Aggressive

angiomyxoma in females Is radical resection the only option

Acta Obstet Gynecol Scand 200079216-20