a 39-year - old woman visited the hospital and presented with a hard , firm and palpable mass in the right upper abdomen . serum levels of the tumor markers , including ca 19 - 9 , carcinoembryonic antigens and ca 125 , as well as laboratory findings , were all normal . excretory urography revealed lateral displacement of the lower pole of the right kidney and ureteropelvic junctional obstruction caused by the space - occupying lesion . an abdominal ultrasonogram ( acuson sequoia 512 ; siemens medical system , erlangen , germany ) showed the presence of a solid medium - echoic retroperitoneal mass with partial invasion of the inferior vena cava ( figs . an examination with 16-channel multi - detector ct ( mx8000 idt ; philips medical system , eindhoven , the netherlands ) revealed the presence of a lobulated and well - defined right retroperitoneal mass measuring 5.15.56.9 cm with extensive cystic degenerations and highly enhanced solid portions on contrast - enhanced scans ( fig . coronal images definitely confirmed the vertically elongated arm - like structures contiguous with the mass , extending upwards to the right renal vein with partial protrusion into the inferior vena cava ( fig . , the mass was connected to the normal right ovarian vein in the pelvis ( fig . both renal and iliac angiograms showed the tumor vessels originating from the inferior segmental branch of the right renal artery . during surgery , the mass was found to be located in the retroperitoneal space inferomedial side of the right kidney . crosscut sections of the tumor showed mainly solid , and partly hemorrhagic and necrotic appearances with a yellow - tinged gray color . microscopically , the tumor showed a typical pattern of intersecting fascicles of spindle cells with hyperchromatic nuclei and eosinophilic cytoplasms , representing the smooth muscle cells in the media . immunohistochemically , the tumor cells were strongly positive for both smooth muscle actin and desmin . expression of cd117 ( kit ) , usually expressed in gastrointestinal stromal tumors and normally negative in leiomyosarcoma , was negative . follow - up abdominopelvic cts after two and three months showed the presence of a 1.0 cm low attenuation nodule in the liver , that had newly developed and enlarged in size over the short - term intervals . we assumed the presence of a liver metastasis , but the patient was lost to further planned follow - up . leiomyosarcomas of the vein arise from the smooth muscle cells of the tunica media of the vessel wall . they grow slowly and bilaterally along the wall of the vessel . retroperitoneal leiomyosarcomas exhibit themselves as completely extravascular ( 62% ) , completely intravascular ( 5% ) or with both extra- and intraluminal growth patterns ( 33% ) ( 6 ) . as the leiomyosarcomas of the inferior vena cava grow , they eventually invade adjacent tissues and metastasize distantly ; however , they tend to expand along the tissue plans of least resistance . there are no reported cases of tissue invasion of the adrenals , kidneys or bowels for leiomyosarcomas of the inferior vena cava ( 7 ) . like other retroperitoneal tumors , these tumors seldom present with symptoms until they progress into a huge mass . when the tumors are discovered at this later stage , there is a poor outlook for long - term survival . as the cases are rare , previously reported radiological findings of a ovarian vein leiomyosarcoma are few in number . the lesions have been merely described as a heterogeneous retroperitoneal mass with ipsilateral hydronephrosis by conventional ct and excretory urography ( 2 , 4 , 5 ) . the findings of excretory urography , representing the effect of mass , are not specific for the diagnosis of the leiomyosarcomas of vascular origin . the general findings of gray - scale ultrasonography of an inferior vena cava leiomyosarcoma are solid but often show cystic necrosis with irregular walls ( 6 , 8) . in our case , the sonographic findings were compatible with those of the ct scans , i.e. , the pedicular structure was a tumor - invading ovarian vein . however , sonography had some limitations in that it failed to demonstrate the whole features of the tumor and the relationship between the tumor and the normal ovarian vein in the pelvis . these limitations may be due to the overlying bowel , the extent of the mass , or limitations in the depth resolution of the ultrasound modality ( 6 ) . the use of ct is superior to the use of sonography to reveal the highly enhancing and necrotic characteristics of the tumor , which is specific for the diagnosis of leiomyosarcoma ( 7 ) . when ct shows a solid or necrotic extraluminal retroperitoneal mass not originating from a retroperitoneal organ , and possessing a contiguous intravascular enhancing appearance , it is accepted as a pathognomonic finding of vascular leiomyosarcoma ( 6 ) . low - attenuation areas representing necrosis , or rarely , a cystic mass due to diffuse necrosis , may be seen ( 7 , 9 ) . in our case , the eccentric cystic area is visible on sonography and ct ; however , the extensive central necrosis is only visible on ct . with great advances in digital imaging and high spatial resolution of multi - detector ct over the last few decades these methods are useful in demonstrating the relationship between a mass and vessels , as well as detecting the tumor or venous thrombi . thus , it was not difficult to presume that the mass originated in the right ovarian vein based on anatomical conceptions , as the tumor possessed vertically elongated bi - armed structures , the typical site of the right ovarian vein . angiography may have a role for demonstrating the primary vessels supplying the tumors and determining the degree of vascularity ( 6 , 9 ) . metastases will occur eventually in most survival cases of other venous or retroperitoneal leiomyosarcomas ( 1 , 2 , 6 ) . the frequent sites for metastases are the liver , lung , brain , and peritoneum ( 1 , 2 , 6 , 8) . local recurrence occurs occasionally in 40% to 77% of cases , even though a complete excision was made ( 6 ) . our case also showed the ct findings of a liver metastasis , although a confirmation was not obtained . in conclusion , the general imaging findings of our case were coincidental with those of other venous or retroperitoneal leiomyosarcomas . sonography seemed to be helpful for the diagnosis of ovarian vein leiomyosarcoma , but the use of multi - detector ct was the tool of choice to confirm the diagnosis . scrolling through multi - stacked images and multiplanar reconstruction of the ct images have great benefits for the preoperative predictions of the location , extent , and growth patterns of the tumor , as well as the relationship of the tumor and vessels . we expect that the primary diagnostic tool for vascular leiomyosarcomas will be the use of multi - detector ct and it may expel the other unnecessary , cost consuming or invasive diagnostic procedures .
leiomyosarcomas of the ovarian vein are very rare . 
 four cases have been reported in the english language clinical literature . 
 we present a case of leiomyosarcomas where the use of multi - detector ct had a substantial role in the establishment of the preoperative diagnosis . 
 the radiological images as well as intraoperative features are illustrated . 
 we also discuss the radiological findings of the ovarian vein leiomyosarcoma in comparison with those of other venous or retroperitoneal leiomyosarcomas . 
 we expect that the use of multi - detector ct will be the choice for the diagnostic work - up of vascular leiomyosarcomas .