lymphangioleiomyomatosis ( lam ) is a rare idiopathic disease that exclusively occurs in women of childbearing age , and this disease is characterized by the proliferation of abnormal smooth muscle cells in the lungs and along the thoracic and abdominal lymphatics ( 1 - 3 ) .
the disease primarily affects the lungs in the majority of cases , but extrapulmonary lam occasionally occurs with or without subsequent involvement of the lungs .
lam involvement of the uterus is extremely rare and there have been only a few such reported cases ( 2 - 7 ) , and the imaging findings of uterine lam have only been briefly mentioned in two reports ( 2 , 5 ) . in this article , we report the cross - sectional imaging findings of extensive lam involving the uterus and pelvic cavity in a 29-year - old woman with tuberous sclerosis complex ( tsc ) and we propose that certain imaging features and the clinical history may suggest the diagnosis . to the best of our knowledge ,
this is the first report of the imaging findings of lam involvement of female pelvic organs .
when she was ten years old , she was diagnosed with tsc based on her history of seizure and mental retardation .
five years previously , she underwent a pelvic magnetic resonance imaging ( mri ) study for the evaluation of menometrorrhagia and dysmenorrhea .
the mr images showed several small ( less than 3 cm ) intramural and subserosal hemorrhagic lesions in the uterus and hematometra ( fig .
adenomyotic cysts and uterine leiomyomas with red degeneration were considered in the differential diagnosis based on the imaging at that time .
endometrial drainage was performed for the hematometra , but no further treatment such as hormonal therapy was done .
for the current visit , her serum ca-125 level was 204.01 u / ml , the ca 19 - 9 level was 50.11 u / ml and the hemoglobin level was 8.7 g / dl .
1c ) showed multiple , large , lobulated , thick - walled cystic masses involving the uterus and the entire pelvic cavity , and these masses extended to the lower abdomen .
the attenuation of the cystic masses was higher than that of simple fluid , which suggested hemorrhagic contents .
both kidneys were enlarged by multiple , various sized masses with attenuations matching fat and soft tissue , which are findings compatible with angiomyolipomas .
pelvic mr imaging showed huge , irregularly - shaped , cystic masses involving the uterus and parauterine pelvic cavity , and these masses were predominantly hyperintense on the fat - saturated t1-weighted image ( fig .
1d ) and they were heterogeneously hypointense and hyperintense on the t2-weighted image ( fig .
these cystic masses were thought to originate from the uterine myometrium on the sagittal t2-weighted image ( fig .
multiple loculated fluid collections with fluid - fluid levels were seen in the cul - de - sac . on the contrast - enhanced t1-weighted image
markedly enlarged lam involving the uterus with extension to the pelvic cavity was suggested as the most probable diagnosis based on the follow - up imaging and clinical findings .
the chest ct showed numerous , well - defined , thin - walled cysts that were diffusely distributed throughout the lungs ( fig .
1 g ) . because the cysts were regularly round in shape and there was no associated nodular lesion , pulmonary lam was the suggested diagnosis , but she had no pulmonary symptoms .
brain mr imaging showed multiple cortical and subcortical tubers as well as several subependymal nodules in the bilateral lateral ventricles , and this represented tuberous sclerosis ( fig .
the intraoperative findings revealed that the uterus was enlarged and distorted by multiple subserosal and intramural hemorrhagic cystic masses .
the cystic masses also involved both adnexae , the pelvic side wall and the omentum .
there were severe adhesive changes between the cystic lesions and the sigmoid colon and bladder .
microscopic examination revealed that the tumor was composed of atypical smooth muscle cells ( lam cells ) arranged in short fascicles around dilated lymphatics and a ramifying network of endothelium - lined spaces ( fig .
immunohistochemical staining showed that the tumor cells were diffusely positive for smooth muscle actin and they were strongly multifocally positive for human melanin black-45 ( hmb-45 ) ( fig .
the patient 's hospital course was uneventful and she was discharged on the tenth postoperative day .
lam results from the proliferation of abnormal - appearing smooth muscle cells in the lymph vessels , which causes dilatation and obstruction in the lymph vessels and this results in cystic collections of chylous material ( 1 ) .
these smooth muscle cells are classified in the family of perivascular epithelioid cells ( pec ) , which is a cell type that is constantly present in a group of tumors , including lam , sugar tumors of the lung and pancreas , renal angiomyolipomas and clear cell myomelanocytic tumor of the falciform ligament ( 8 , 9 ) .
these so - called " pecoma " all express hmb-45 ( 8) . lam occurs in about 30% of the women with tuberous sclerosis complex ( tsc ) , which is an autosomal dominant multisystem neurocutaneous disorder of highly variable penetrance , and it is characterized by hamartomas , seizure and mental retardation ( 1 ) . due to the striking similarities in the pathological processes between the lam and tsc , lam has been considered a forme fruste of tsc , and lam is classified as a tsc - associated or sporadic form ( 5 , 10 ) .
lymphangioleiomyomatosis predominantly affects the lung parenchyma and this is characterized by pulmonary cysts seen on ct .
the extrapulmonary manifestation of lam is uncommon and this is mainly located in the retroperitoneum , pelvic cavity and the posterior mediastinum along the lymphatic channels ( 1 - 7 ) . in a large study of 80 patients with pulmonary lam ( 11 ) ,
the ct imaging findings of retroperitoneal lam were described as a low - attenuating ( 3 - 25 hounsfield unit [ hu ] ) , multilobulated mass , and the ultrasound findings were reported as a cystic mass with a thick echogenic rind .
uterine involvement of lam is extremely rare , and to the best of our knowledge , only eight cases of pathologically proven uterine lam have currently been reported ( 2 - 7 ) .
six cases of uterine lam occurred in patients with the stigmata of tsc , and two patients did not have stigmata of tsc .
most uterine lams were microscopic and they are incidentally found in patients undergoing evaluation for extrauterine disease ( 2 ) .
menorrhagia and/or pelvic pain have been reported in half of the cases , the same as in our case ( 2 - 7 ) .
the imaging findings of uterine lam were briefly mentioned in two gynaecological reports ( 2 , 5 ) .
( 2 ) reported that uterine lam simulated high - stage endometrial stromal sarcoma , and the ct finding of uterine lam was described as a large uterine mass , which was thought to be a fibroid .
however , the surgery revealed multiple subserosal and intramural hemorrhagic nodules ranging in size from 2.5 to 4.0 cm and bloody ascites due to tumor perforation .
( 5 ) recently reported on a 5.5-cm hypervascular tumor between the uterus and the right ovary that showed low signal intensity on the t1-weighted mr image and intermediate signal intensity on the t2-weighted mr image .
this mri finding is quite different from that of retroperitoneal lam and it is rather similar to that of uterine leiomyoma .
the pathological examination in that case revealed multiple intramural leiomyomas and several fragments of irregular soft masses composed of hmb 45 positive lam cells .
the most remarkable aspects of our case are the initial involvement of lam in the uterus that gradually grew into the pelvic cavity and the intratumoral bleeding .
intratumoral bleeding may be caused by overdistention and rupture of the cysts . although the ct findings showed highly attenuating cystic masses involving the uterus and pelvic cavity , the mr imaging confirmed the hemorrhagic cystic nature of the masses by their signal intensity and the mr imaging exactly localized the masses .
these imaging findings are consistent with the known imaging findings of retroperitoneal lam . however , if a patient is without a clinical history of tsc , then uterine intramural and subserosal leiomyomas with hemorrhagic and cystic degeneration , adenomyotic cysts and/or endometrial cysts , and malignant uterine and/or ovarian tumors with hemorrhage should be considered in the differential diagnosis . in summary
, we report here on the extraordinary radiological findings of lam involving the uterus and pelvic cavity in a young woman with tsc .
although uterine lam is rare , radiologists should consider the possibility of this disease when they see multiple cystic uterine or parauterine masses with or without internal hemorrhage in a patient with a history of tsc or pulmonary lam .
 lymphangioleiomyomatosis ( lam ) is a rare idiopathic disease and this is characterized by a proliferation of abnormal smooth muscle cells in the lungs and in the lymphatic system of the thorax and retroperitoneum . 
 the female genital tract is rarely affected by lam . 
 we report here on the ct and mr imaging findings of extensive lam involving the uterus and pelvic cavity , and this was seen as multiple cystic uterine and parauterine masses with internal hemorrhage in a young female with tuberous sclerosis complex . 
INTRODUCTION
CASE REPORT
DISCUSSION