sarcomatoid carcinoma is a rare histopathological entity with uncertain histogenesis that is composed of mixed carcinoma cells and mesenchymal cells . it is known to occur in various organs , but is most common in the head and neck , lung , and female genital tract . sometimes it arises in the gastrointestinal tract , predominantly in the esophagus or the stomach . colonic sarcomatoid carcinomas are rare tumors , with 22 cases documented either as sarcomatoid carcinomas or carcinosarcomas in the literature [ 4 - 25 ] . this tumor is generally aggressive with a poor prognosis . here , we present a case of sarcomatoid carcinoma in the sigmoid colon which was extremely aggressive a 59-year - old man who had no significant past medical history was presented to the hospital with lower abdominal pain and discomfort which had begun 2 weeks earlier . physical examination revealed a nontender , fetal - head - sized hard mass on palpation of the lower abdomen . laboratory evaluation revealed anemia ( 9.5 g / dl ) with elevated serum levels of carcinoembryonic antigen and carbohydrate antigen 19 - 9 ( 13.59 ng / ml , 56.07 u / ml ) . abdominal sonogram showed a large mass in the pelvic cavity with ascites and a metastatic liver nodule in s8 . one day after admission , the patient complained of severe abdominal pain , and the serum hemoglobin level decreased to 7.15 g / dl . computed tomography ( ct ) showed a ruptured 14  15  12 cm sized heterogenous low density mass in the pelvic cavity with fluid collection ( fig . 1 ) , and there were multiple liver nodules and an enhanced nodule with fat infiltration in the omentum ( fig . urgent laparotomy was performed and multiple liver metastases and peritoneal and omental seeding of the tumor were found . worsening abdominal distension and vomiting occurred 10 days after operation , and a repeat ct showed a 10  13 cm sized new mass in the pelvic cavity with small bowel obstruction . repeat laparotomy was performed for palliative cytoreductive treatment , with small bowel resection and end ileostomy with debulking . the patient tolerated a slight advance in diet after the second surgery for three days , but ultimately abdominal distension recurred with a hard palpable mass , and the patient died of abdominal compartment syndrome due to rapid tumor growth 22 days after the initial operation . histologic examination revealed an invasive tumor with two components : the luminal surface of the tumor was mainly composed of moderately differentiated adenocarcinoma , and in the deeper area there were spindle and epithelioid cells showing high grade anaplasia , which morphologically corresponded to the sarcoma ( fig . five of eight lymph nodes isolated in the pericolic fat were positive for tumor metastasis . sarcomatoid carcinoma is widely considered a rare , highly aggressive tumor which arises most commonly in the head and neck or female genital tract . it sometimes involves the upper aerodigestive tract such as the stomach and esophagus , and most have polypoid growth patterns and can be diagnosed early in their course , so are associated with a relatively favorable prognosis . however , since the time that weidner and zekan   reported the first case of colonic sarcomatoid carcinoma , most sarcomatoid carcinomas of the colon have been found to have an aggressive clinical course , often presenting with symptoms or signs related to distant metastasis . to our knowledge , there have been 22 cases of colon carcinosarcomas and sarcomatoid carcinomas reported in the literature [ 4 - 25 ] , and are summarized in table 1 . mean age of diagnosis was 63.70  17.64 years ( male , 71.78  10.79 ; female , 58.50  19.51 ) with an age range of 13 to 86 years . eighteen patients ( 78% ) have metastasis with the liver being the most common location . there were 5 cases of right side colon ( cecum and ascending colon ) , 2 cases of transverse colon , 5 cases of left side colon , and 11 cases ( 48% ) of sigmoid colon and rectal sarcomatoid carcinoma . the prognosis is poor , with patients dying within 6 months of diagnosis in 13 ( 56% ) of 23 cases . however , the molecular analysis perfomed in the current case supports the hypothesis of a common cell precursor since the same mutation ( r282w in exon 8 of the p53 gene ) and the same allelic status ( with the loss of 18q21 ) were identified in both the carcinomatous and sarcomatous components . it is known that lymph nodes and distant metastases show a predominance of the carcinomatous component , and only one case has been documented that shows metastasis with the sarcomatous component . there are no specific treatment guidelines due to the limited number of cases of colonic sarcomatoid carcinoma , however , radical surgery with adjuvant chemotherapy and close follow - up may be an acceptable approach to this disease . in this case , our patient unfortunately had no chance for adjuvant chemotherapy . despite two operations , the patient did not survive past 22 days due to rapid tumor growth . the present case may be the most aggressive case of colonic sarcomatoid carcinoma reported so far .
colonic sarcomatoid carcinomas are known to be extremely rare tumors , with only 22 cases reported either as sarcomatoid carcinomas or carcinosarcomas in the literature . 
 the known characteristics are rapid growth , a high recurrence rate , and an extremely poor prognosis . 
 herein we report a case of a patient who had a sarcomatoid carcinoma of the sigmoid colon and died only 22 days after surgery due to rapid tumor growth .