aggressive angiomyxoma ( aa ) is a rare benign soft tissue tumour usually affecting the pelvis and perineum of young women .
magnetic resonance imaging ( mri ) is crucial in the management of aa patients for its diagnostic contribution and for the preoperative assessment of the actual tumour extension . given the current development of less aggressive therapeutics associated with a higher risk of recurrence , close follow - up with mri is fundamental after treatment .
in this context , diffusion - weighted ( dw ) imaging has already shown high efficacy in the detection of early small relapses in prostate or rectal cancer .
we report here a case of pelvic aa in a 51-year - old woman examined with dynamic contrast enhancement and dw - mri , including apparent diffusion coefficient mapping and calculation .
to our knowledge , this is the first description of dw - mri in aa reported in the literature . here ,
aggressive angiomyxoma ( aa ) is a benign soft tissue tumour with myxoid and vascular components that arises mostly in the lower pelvis and perineum in women of reproductive age .
most of them ( > 90% ) occurred in young women , usually in the second to fourth decade .
the risks of local extension and postoperative local relapse justify surgical excision of the tumour .
imaging and particularly magnetic resonance imaging ( mri ) are fundamental for the clinical management of aa .
precise preoperative assessment of local extension is crucial to plan the best surgical approach for tumour removal involving as little mutilation as possible .
mri allows the monitoring of the response to possible preoperative treatment such as hormone therapy . finally , it is also crucial during the patient 's follow - up after initial treatment . for a few years now
, classical mri coupled with diffusion - weighted ( dw ) sequences has developed in oncology , leading to improvements in the detection and characterization of tumours , treatment response monitoring , and detection of recurrence [ 3 , 4 ] . to our knowledge , we report here the first case of pelvic aa explored with dw - mri and dynamic contrast enhancement ( dce)-mri .
in july 2011 , a 51-year - old woman presented to her general practitioner with an incidentally discovered renitent mass in the internal part of the left buttock .
initial ultrasound ( us ) showed a well - circumscribed mass initially evoking a lipoma . due to the large volume of the mass ,
she was otherwise asymptomatic with a performance status score of 0 on the who scale .
us showed a superficial , soft , hypoechoic , well - limited , solid mass .
mri showed a bulky perineal and intrapelvic tumour displacing rather than infiltrating the vagina , anal canal , and rectal structures .
the mass was well limited , hourglass - shaped and had a maximum diameter of 11 cm ( fig .
t2-weighted imaging showed typical high signal intensity with layered strands of lower signal intensity and swirled architecture .
a fat linear structure of high signal intensity on t1- and t2-weighted images was present inside the mass .
its significance was unknown , perhaps representing neighbouring tissues trapped when the tumour was growing .
after intravenous contrast injection , the mass was greatly and heterogeneously enhanced , exhibiting a layered pattern ( fig .
regions of interest located in the layers demonstrated the same profile curves of progressive enhancement with variable intensity .
apparent diffusion coefficient ( adc ) mapping showed a high value in the tumour , estimated at 2  10 ( 0.15 ) mm / sec .
it also showed disease extension , notably through the pelvic diaphragm , which made a combined transperineal and laparoscopic abdominopelvic approach necessary . before surgery
, the examination under general anesthesia showed that the mass was soft , renitent , and seemed to come from the pelvic cavity through the levator ani muscles .
tumour excision was monobloc and macroscopically complete , without any rectal or vaginal resection or tumour capsular rupture .
macroscopic examination of the surgical specimen showed a firm , partly circumscribed tumour measuring 16  12  6.5 cm .
a cut section showed a homogeneous , glistening , and gelatinous appearance without any hemorrhagic or necrotic areas .
microscopic analysis showed a monotonous hypocellular proliferation of small nonatypical stellate - shaped cells arranged in a myxoid stroma , along with numerous , variably sized vessels .
no mitosis or necrosis could be seen . in its periphery , the proliferation infiltrated the nontumour adipose tissue , and resection margins were focally involved by the tumour cells .
immunohistochemical analysis showed strong expression of cd34 , and estrogen and progesterone receptors by tumour cells , without expression of desmin , cd117 , -catenine , and mdm2 , nor epithelial ( pancytokeratin , ema ) , smooth muscle ( -smooth actin , h - caldesmon ) , and schwann cell ( ps100 ) markers .
after surgery , no adjuvant treatment was given , and the patient was regularly monitored clinically and radiologically . at her last visit , in october 2012 , more than 1 year after the diagnosis , the patient was alive with an excellent performance status and without any recurrence of the disease on pelvic dw - mri .
aa is a compliant tumour that grows slowly in the perineal or pelvic region and can cross the pelvic diaphragm .
classically , the tumour shows finger - like projections at the periphery and into the surrounding tissue without infiltrating or invading adjacent organs . in general , the tumour is well limited and large ( often more than 10 cm in diameter ) at the time of diagnosis , and its consistency is soft or renitent [ 1 , 6 ] .
histologically , aa is a benign hypocellular tumour , composed of scattered spindle or stellar cells , embedded in a loose myxoid matrix with a few collagen fibers and abundant vessels of varying sizes .
frequently , tumour cells show positive immunohistochemical staining for desmin , smooth muscle actin , muscle - specific actin , and hormone receptors .
rare and recent molecular analyses have identified translocation in the 12q1315 region involving the hmga2 gene .
aggressiveness is related to the high rate of local recurrence after surgery because of frequent incomplete excision .
this can be due to the absence of a preoperative diagnosis and estimation of the actual extent of the tumour , or to a particular strategic location of the mass near the urethra , vagina , anal sphincter and rectum , with frequent extension through the pelvic diaphragm , making complete resection difficult .
the formerly high rate of relapse has decreased from ~75 to 1030% during the last 20 years thanks to improved imaging techniques , which allow a more complete surgical resection .
aa in men is unusual and affects the genitourinary tract  especially the scrotum and inguinal region [ 1 , 4 ] .
most patients present with a slow - growing palpable or visible mass in the pelvi - perineal region .
other signs may include discomfort or pain due to the mass , or signs related to pressure effects on adjacent organs such as dyspareunia and dysuria .
morphological imaging like computed tomography ( ct ) checks for the absence of pelvic hernia , gynaecological prolapse or myoma .
vaginal cysts , gartner cysts and bartholin cysts are frequent and easy differential diagnoses that do not show significant enhancement except if infected . in that case , mri will usually show peripheral enhancement of the wall of the cyst with variable thickness , which is totally different from the aa pattern of enhancement .
the lack of macroscopic fat on ct and mri sequences with and without fat suppression can rule out infiltrating angiolipoma and lipoma or liposarcoma with or without myxoid component [ 7 , 8 ] . endometriomas and melanomas show typical high signal intensity on t1-weighted images without signal intensity dropout on fat - suppressed images .
myxoma is mainly an intramuscular tumour that occurs in older patients , and whose enhancement does not show the same features as aa .
mri is also a helpful diagnostic tool with in - phase and opposed - phase sequences showing microscopic fat inside the angiomyofibroblastoma .
other diagnoses such as myxoid neurofibroma , myxoid - type malignant fibrous histiocytoma , myxofibrosarcoma , vaginal botryoid pseudosarcoma , and rhabdomyosarcoma are made by histological analysis of the tumour .
in general , mri will help with the preoperative diagnosis by showing typical images of aa , as in our case .
this is all the more important because , if the final diagnosis is obviously based on histology and immunohistochemistry , a preoperative diagnosis may be difficult to obtain from a percutaneous biopsy .
typical images show the lesion as a well - limited mass , displacing rather than infiltrating adjacent organs and muscles , with content rich in water , loose myxoid matrix , and hypervascularity .
finger - like projections into neighbouring adipose tissue can be present and are relatively characteristic of aa .
classically , us without contrast injection shows a homogeneous and hypoechoic mass , sometimes cystic , that may be misleading .
ct scan shows an enhanced mass , which is iso- or hypoattenuating relative to muscle [ 7 , 11 ] .
mri shows very characteristic aspects : an isointense tumour ( more rarely hypointense ) relative to muscle on t1-weighted images , and hyperintense on t2-weighted images ( high water content and loose myxoid matrix ) [ 2 , 5 , 7 ] .
the tumour enhances avidly and heterogeneously after intravenous gadolinium contrast administration , reflecting its inherent vasculature [ 2 , 5 , 7 , 8 ] .
a typical mri feature of aa is the presence of an internal layered pattern and/or swirled architecture , which is described in 83% of cases on t2-weighted mri or on t1-weighted mri after intravenous contrast injection [ 2 , 5 , 6 , 7 , 8 , 9 ] .
our case perfectly illustrated these mri findings , allowing us to suspect the aa diagnosis before surgery .
preoperative mri is also crucial to determine the true extent of the disease and plan the most optimal surgical approach .
the importance of accurate preoperative diagnosis and extent screening is clearly reported . in our case
, an abdominoperineal approach was chosen as the tumour extended above the pelvic diaphragm on mri , allowing complete resection . during treatment
finally , mri is very helpful in order to detect local relapses during follow - up .
because of its high sensitivity in detecting tumour presence , its noninvasive nature , and its ability to provide valuable qualitative and quantitative information , dwi has become indispensable for characterizing lesions , and for monitoring the response to nonsurgical therapy and the patient 's follow - up after treatment .
this is already well documented for the detection of prostate or rectal cancer relapse . to our knowledge
the typical architecture of the tumour was seen on t2-weighted images and b0 sequences ; however , it disappeared both as the b value increased and on adc mapping imaging even in a mass more than 10 cm in diameter .
dwi also showed a high value of tumour adc measurements in the region of 2  10 mm / sec , comparable with adc calculations in myxoid tumours .
the persistence of high tumour signal intensity on dwi with a high b value suggests the possibility of easy and earlier relapse diagnosis using these types of sequences .
furthermore , we can hypothesize that normal mri using dw sequences during patients follow - up is probably an effective way to confirm the absence of recurrence .
however , aa can theoretically be polymorphous , and more patients in larger case series are needed to confirm these first observations . due to the rarity of this disease ,
wide surgical resection is the treatment of choice , sometimes after preoperative angiographic embolization to decrease the size of the tumour .
but , because of its frequently large size and location in close proximity to vital organs ( urogenital tract and rectum ) , wide excision is not always possible and/or may cause significant morbidity in young patients .
furthermore , the prognostic value of extensive surgical resection to obtain clear margins is questioned . a review of over 100 cases published in 2000 by chan et al
.   showed that patients with clear resection margins have similar chances of remaining disease free ( 50% at 10 years ) compared with those having tumour - involved resection margins ( 40% ) .
these observations explain that incomplete resection is acceptable nowadays if followed by long - term follow - up and careful monitoring for timely identification and prompt resection of relapse .
treatment involving chemotherapy and radiotherapy has been disappointing , probably due to the low mitotic activity of the tumours [ 1 , 11 ] .
aa is likely hormone dependent as suggested by the reproductive age of the patients , the few cases reported during pregnancy , and the frequent expression of hormone receptors .
thus , gonadotropin - releasing hormone agonists have been administered to aa patients in the postoperative as well as in the preoperative setting with dramatic responses , facilitating surgery or avoiding mutilating surgery [ 10 , 13 , 14 ] .
one case report of aa treated exclusively with gonadotropin - releasing hormone agonists was published in 2003 .
two cases of successful control of recurrent aa with relatively high doses of external radiotherapy have been reported , but a literature analysis shows a definite shift towards less morbid treatments .
after treatment , long - term follow - up is required since late recurrences have been described up to 14 years following treatment .
recurrence rates are variable in the literature and probably depend on when patients were treated ( related to surgical and mri quality ) .
.   found a recurrence rate in the region of 50% between 1984 and 1998 .
. otherwise , 71% of recurrences occurred within the first 3 years , regardless of the initial tumour size and patient 's age .
periodic clinical examination may be insufficient and imaging studies , such as mri , are fundamental .
they may detect recurrence early , when the tumour is smaller in size , making surgery easier to perform or allowing the use of less morbid percutaneous ablative therapeutic strategies such as radiofrequency ablation or cryotherapy .
mri is crucial in the management of aa patients for its diagnostic contribution and preoperative assessment of the actual extent of the tumour . during eventual neoadjuvant treatment ,
it allows monitoring of the tumour response and , after treatment , it is very useful for detecting recurrences . here , we presented the use of mri in a typical case of aa .
however , this case report is also the first description in the literature of aa with complete dce and dwi analysis .
we have updated the current knowledge on aa and , furthermore , we recommend the use of diffusion sequences in the follow - up of young patients treated for aa , regardless of what type of treatment they have previously had .
 introductionaggressive angiomyxoma ( aa ) is a rare benign soft tissue tumour usually affecting the pelvis and perineum of young women . 
 magnetic resonance imaging ( mri ) is crucial in the management of aa patients for its diagnostic contribution and for the preoperative assessment of the actual tumour extension . given the current development of less aggressive therapeutics associated with a higher risk of recurrence , close follow - up with mri is fundamental after treatment . 
 in this context , diffusion - weighted ( dw ) imaging has already shown high efficacy in the detection of early small relapses in prostate or rectal cancer.case reportwe report here a case of pelvic aa in a 51-year - old woman examined with dynamic contrast enhancement and dw - mri , including apparent diffusion coefficient mapping and calculation.conclusionto our knowledge , this is the first description of dw - mri in aa reported in the literature . here , 
 knowledge about imaging features of aa will be reviewed and expanded . 
Introduction
Case Report
Conclusion
Introduction
Case Report
Discussion
Conclusion