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endometrial stromal sarcomas ( ess ) are uncommon mesenchymal tumors of the uterus which are composed of cells closely resembling normal proliferative endometrial stromal tissue . traditionally , ess were classified into low - grade and high - grade ess based on mitotic rate .
high - grade tumors however , have little resemblance to original endometrial stroma . therefore , high - grade tumors are presently classified as undifferentiated endometrial or uterine sarcoma . in this classification
the differentiation between low - grade and undifferentiated tumors is not made on mitotic count but on the presence of nuclear pleomorphism and necrosis .
standard treatment for ess is total abdominal hysterectomy and bilateral salpingo - oophorectomy . when there is extra - uterine spread complete debulking of all tumor is recommended .
we present a patient presenting with rectal bleeding , based on a very late recurrence of a formerly misdiagnosed low grade ess metastasized to the colon .
a 78 year old woman presented with rectal bleeding and recurrent lower urinary tract infections in july 2009 .
her medical history showed a total abdominal hysterectomy and bilateral salpingo - oophorectomy because of a uterus myomatosus with severe blood loss in 1983 and a laparotomy with excision of a retroperitoneal cyst in 1992 .
our patient underwent a colonoscopy which revealed a malignant circumferential obstructing tumor 28  cm from the anal verge ( fig .
computed tomography showed a suspicious tumor of 8  cm , at the site of the sigmoid , closely related to the urinary bladder .
urine analysis revealed some atypical cells , but no signs for urinary tract infection or malignant cells .
a hartmann 's resection was performed with a partial cystectomy which was closed primarily and the patient received a urinary catheter for one week .
one month postoperative she underwent intraperitoneal stomal revision , because of a retracted necrotizing colostomy .
pathologic examination showed a submucosal low grade ess of 8  cm in diameter arising from the colon with nodular invasion of the mesocolon and three lymph nodes which all contained metastases of ess ( figs . 2 and 3 ) .
resection margins were free from tumor . in the context of this finding revision of the original resections of the retroperitoneal cyst and the uterus and adnexa
this revision revealed , both histomorphological as well as immunophenotypical , an equivalent aspect as the newly resected colon tumor .
final pathologic diagnosis therefore , was a very late colonic recurrence of a low grade uterine ess .
endometrial stromal sarcomas are rare tumors , contributing for 0.2% of all uterine malignancies and 715% of all uterine sarcomas . initially , histological classification consisted of carcinosarcomas ( 40% ) , leiomyosarcomas ( 40% ) , ess ( 15% ) and undifferentiated sarcomas ( 5% ) .
currently , the carcinosarcomas have been reclassified as a differentiated or metaplastic form of endometrial carcinoma according to the international federation of gynaecology and obstetrics ( figo ) classification .
ess are difficult to diagnose because of close resemblance to normal proliferative endometrial cells , and because of the rarity of the condition . prior to surgical resection ess
are often misdiagnosed as leiomyoma or other uterine benign diseases and after resection also histological examination frequently misses the diagnosis .
incidence peaks occur in premenopausal women between 40 and 55 years of age who are asymptomatic or present with vaginal bleeding or pelvic or abdominal pain .
ess can occur in patients with endometriosis and in patients with a prolonged exposure to estrogens , e.g. patients with polycystic ovarian disease , or after estrogen use or tamoxifen therapy .
it is thought that the exposure to estrogens causes a proliferative effect on the endometrial stroma .
patients with stage i  ii tumors have a 5-year overall survival of 89.3% compared to 50.3% in patients with stage iii  iv tumors .
tumor behaviour is apprehensive for a tendency of late recurrence . in patients with stage i disease ,
the median time to recurrence is 65 months compared to 9 months in patients with stage iii 
recurrences occur in 3656% of patients , most frequently in the pelvic cavity or the lungs .
metastatic spread to the cerebrum and bones and invasion in the great vessels have also been described .
recurrences arising in the small bowel and colon are intimately associated with endometriosis . as the rectosigmoid has the highest incidence of intestinal endometriosis , ess arising within endometriosis
our patient developed a very late recurrence in the rectosigmoid , although she had no history of endometriosis .
pathologic revision did not reveal any signs of endometriosis , but the presence of a small endometriosis spot as an origin for the metastasis can not be excluded .
standard treatment for ess is total abdominal hysterectomy with bilateral salpingo - oophorectomy , even at premenopausal ages .
they are often sensitive to hormones and it is presumed that patients preserving their ovaries have a higher risk of recurrence and poorer overall outcome .
some studies advocate considering re - exploration for removal of ovaries while others state that ovarian preservation has no effect on recurrences or overall survival . in premenopausal women ovaries
are frequently preserved , which does not affect the risk of recurrence in stage i patients .
lymph node metastases have been found in 7% of patients with low - grade ess . performing a lymph node dissection , regardless of the finding of any microscopic positive nodes ,
five - year survival is 85.7% in lymph node positive patients compared to 95.2% in lymph node negative patients .
post - operative radiotherapy decreases the risk of local recurrence , especially in grade ii 
postoperative treatment with chemotherapy could might be an option in patients with hormone - unresponsive tumors and for inoperable patients .
hormonal therapy can be an important treatment because of the hormonal sensitivity of the tumor .
adjuvant progestagens should be considered in patients with ess . in patients with completely resected low - grade ess
tamoxifen and estrogens are contraindicated because of the possible stimulative effect on disseminated endometrial stromal cells .
our patient underwent a hysterectomy in 1983 because of a uterus myomatosus accompanied with severe blood loss and excision of a retroperitoneal cyst in 1992 .
that means our patient probably had stage i ess in 1983 , which was initially not recognized as ess , but was probably regarded as a cell rich variant of leiomyoma . after nine years she developed the first retroperitoneal recurrence . at this time the tumor was detected as a malignant mesenchymal tumor , but was not recognized as ess .
a recurrent ess localized in the submucosa of the colon , in the absence of endometriosis , with fixation to the urinary bladder is a very rare finding .
the accompanying lymphogenic spread is uncommon . during the first surgery , at 52 years of age , our patient underwent a hysterectomy for a uterus myomatosus with bilateral oophorectomy .
she never took hormonal replacement therapy except for local estrogens for a few weeks and she was not familiar with endometriosis .
prior to her third surgery in 2009 , she was diagnosed with recurrent lower urinary tract infections .
urine analysis revealed some atypical cells , presumably due to tumor invasion in the urinary bladder .
final pathologic examination of the operatively removed tumor however , could not confirm spread of tumor into the bladder wall , since no urinary bladder wall was recognized in the specimen .
patient was discussed in our multidisciplinary oncology panel and because of the controversy about adjuvant therapy in the treatment of ess , in combination with the radical surgery and the long disease free period after the primary presentation and the first recurrence , no additional treatment was advised and follow up will take place on a regular base once a year .
tumor behaviour is apprehensive for a tendency of late recurrence . in patients with stage i disease ,
the median time to recurrence is 65 months compared to 9 months in patients with stage iii 
recurrences occur in 3656% of patients , most frequently in the pelvic cavity or the lungs .
metastatic spread to the cerebrum and bones and invasion in the great vessels have also been described .
recurrences arising in the small bowel and colon are intimately associated with endometriosis . as the rectosigmoid has the highest incidence of intestinal endometriosis , ess arising within endometriosis
our patient developed a very late recurrence in the rectosigmoid , although she had no history of endometriosis .
pathologic revision did not reveal any signs of endometriosis , but the presence of a small endometriosis spot as an origin for the metastasis can not be excluded .
standard treatment for ess is total abdominal hysterectomy with bilateral salpingo - oophorectomy , even at premenopausal ages .
they are often sensitive to hormones and it is presumed that patients preserving their ovaries have a higher risk of recurrence and poorer overall outcome .
some studies advocate considering re - exploration for removal of ovaries while others state that ovarian preservation has no effect on recurrences or overall survival . in premenopausal women ovaries
are frequently preserved , which does not affect the risk of recurrence in stage i patients .
lymph node metastases have been found in 7% of patients with low - grade ess . performing a lymph node dissection , regardless of the finding of any microscopic positive nodes ,
five - year survival is 85.7% in lymph node positive patients compared to 95.2% in lymph node negative patients .
post - operative radiotherapy decreases the risk of local recurrence , especially in grade ii 
postoperative treatment with chemotherapy could might be an option in patients with hormone - unresponsive tumors and for inoperable patients .
hormonal therapy can be an important treatment because of the hormonal sensitivity of the tumor .
adjuvant progestagens should be considered in patients with ess . in patients with completely resected low - grade ess
tamoxifen and estrogens are contraindicated because of the possible stimulative effect on disseminated endometrial stromal cells .
our patient underwent a hysterectomy in 1983 because of a uterus myomatosus accompanied with severe blood loss and excision of a retroperitoneal cyst in 1992 .
that means our patient probably had stage i ess in 1983 , which was initially not recognized as ess , but was probably regarded as a cell rich variant of leiomyoma . after nine years she developed the first retroperitoneal recurrence . at this time the tumor was detected as a malignant mesenchymal tumor , but was not recognized as ess .
a recurrent ess localized in the submucosa of the colon , in the absence of endometriosis , with fixation to the urinary bladder is a very rare finding .
the accompanying lymphogenic spread is uncommon . during the first surgery , at 52 years of age
she never took hormonal replacement therapy except for local estrogens for a few weeks and she was not familiar with endometriosis .
prior to her third surgery in 2009 , she was diagnosed with recurrent lower urinary tract infections .
urine analysis revealed some atypical cells , presumably due to tumor invasion in the urinary bladder .
final pathologic examination of the operatively removed tumor however , could not confirm spread of tumor into the bladder wall , since no urinary bladder wall was recognized in the specimen .
patient was discussed in our multidisciplinary oncology panel and because of the controversy about adjuvant therapy in the treatment of ess , in combination with the radical surgery and the long disease free period after the primary presentation and the first recurrence , no additional treatment was advised and follow up will take place on a regular base once a year .
in conclusion , low - grade ess are uncommon tumors of the uterus with an indolent clinical course and favourable prognosis .
total abdominal hysterectomy with bilateral salpingo - oophorectomy is the treatment of choice . in patients with a history known for ess , a recurrence
if recurrence occurs , radical surgery should be performed and adjuvant hormonal therapy may be considered .
there was no financial support for the conduct of the study and the writing of the manuscript .
written informed consent was obtained from the patient for publication of this case report and accompanying images .
a copy of the written consent is available for review by the editor - in - chief of this journal on request .
introductionendometrial stromal sarcomas are rare mesenchymal neoplasms of the uterus with an indolent clinical course but a high risk of recurrence.presentation of casewe report a case of a 78 year old woman who presented with rectal bleeding and recurrent urinary tract infections , caused by a very late recurrence of a formerly misdiagnosed low grade endometrial stromal sarcoma , metastasized to the colon.discussionendometrial stromal sarcomas are difficult to diagnose , both due to the rarity of the tumor and because of the close resemblance of the tumor to normal stromal tissue . 
 these tumors are known for a high tendency of recurrence , therefore long term follow up is required in patients with endometrial stromal sarcoma.conclusionin patients with a history known for endometrial stromal sarcoma recurrence should always be considered .