Primary Ewing’s sarcoma in a small intestine – a case report and review of the literature

Background Ewing’s sarcoma usually presents in paediatric patients with its primary location being bone tissue. Nevertheless, we present such an adult case which arises from the small intestine. We registered thirty one cases of such origin published so far excluding ours. Case presentation We report a case of 30 year old female who was admitted due to the persistent anaemia. Whole body computed tomography scan revealed abdominal mass in her left upper abdominal compartment. Surgery on the mass originating from jejunum was performed, although due to extremely complicated postoperative period and rapid dissemination no additional therapy had been performed. The tumour was positive for CD99, ERG, CD56, Synaptophysin, PanCK, Cam5.2. Conclusion Extraosseus Ewing’s sarcoma is extremely rare entity, with poor prognosis.

more cases with metastatic spread or extra skeletal tumours [3]. The common sites of Ewing's sarcoma recurrence are the soft tissue of the lower extremities, paravertebral region, and pelvis [14]. Five year overall survival rate is 44% (ranging 20-60%) [16]. Up to date only 31 cases of extraosseus Ewing's sarcoma arising in a small intestine are reported in the literature (Table 1).
Here we present a case of Ewing's sarcoma in a small intestine with an extremely rapid dissemination and unfortunate ending.

Case presentation
Here we present a 30 year old female admitted to local hospital complaining of mild general weakness lasting for four months. Full blood count showed severe anaemia of 54 g/l and a mild gastric wall inflammation was seen on gastroscopy. Blood transfusion in therapeutic ward was then performed. Whole body computed tomography (CT) scan discovered 4.7 × 6.2 × 6.5 cm non-homogenic tumour with a cystic component in a left upper abdominal compartment. Tumour had a close contact with an inferior mesenteric vein (IMV) at the long segment, near the entrance to the superior mesenteric vein (SMV) (Type A/B) without overgrowing any another surrounding organ. Gastrointestinal stromal tumour (GIST) was suspected (Figs. 1 and 2). Patient was transferred to our cancer institute and after multidisciplinary team discussion she was elected for a surgeryremoval of the GIST of the jejunum. The patient had no previous medical history of other diseases, surgeries or allergies. Her initial blood test showed haemoglobin of 74.6 g/l, so additional blood transfusion was performed.
On laparotomy the tumour involving the first loop of the small intestine (30 cm from the Treitz ligament), a part of uncinated process of the pancreas, IMV and inferior mesenteric artery (IMA) was found. Enlarged small intestine lymph nodes were also seen. Resection of 50 cm of small intestine with the tumour was performed. Two layer end-to-end entero-entero anastomosis was performed and enteral feeding tube was inserted below the anastomosis. Early postoperative course was uneventful. On postoperative day (POD) five the blood appeared through the drainsemergency surgery was initiated. Massive bleeding from superior mesenteric artery (SMA) was found and the arterial defect was sutured. The cyanotic small intestines were noticed and a partial occlusion of SMA was suspected. Aortomesenteric shunt using saphenous vein was performed and the small intestine regained its blood supply. Two days later anastomotic leak was suspectedbile from the drain was noticed. Anastomosis was resected and two layer side-to-side duodenojejunal anastomosis was performed. By then, the pathology report revealed a high grade G3 peripheral/primitive neuroectodermal tumour (PNET)/atypical Ewing sarcoma which expansion to the pancreas (Figs. 3, 4, 5, 6, 7 and 8). R1 resection (at the uncinated process of the pancreas) was confirmed (pT4N1, LVI [2]).

Postoperative period
Eleven days after the third surgery bleeding recurredbleeding from the aorto-mesenteric shunt was found. It was sutured along its wall and intraoperative ultrasound showed reduced diameter of the shunt, and recanalized SMA. During postoperative period due to progressing bile leakage, bile ducts were catheterized trans-hepatically. Nine days later intraabdominal bleeding recurred. Bleeding from the aorta at the shunt area was found and sutured. Small intestine on the other hand showed total necrosis with multiple perforations. The changes were incompatible with life. Nonetheless 48 h later, patient vital signs improved and the condition stabilized. Therefore, during the next surgery necrotised small intestine was removed while closing both ends of the intestines at the demarcation lines and gastrostomy was made for the drainage of the gastric content. During the next few weeks bleeding recurred and multiple (> 50) liver metastases were found. Bleeding was controlled but the patient died because of rapid dissemination of the disease.

Discussion and Conclusion
Intestinal Ewing's sarcoma as many other tumours can manifest asymptomatic although there are cases in   which it occurs as intussusception [18], perforation [11,15], intestinal obstruction [14,23], rupture [4] but usually it presents with abdominal pain or fatigue and weakness caused by mass and/or bleeding as in our case. It can be misdiagnosed as a gynaecologic pathology especially in young females as the literature shows pain can often occur in the lower abdomen [6,13,20]. Clinical presentation mainly depends on the affected site of the gastrointestinal tract [19]. Thorough examination should follow CT scan to exclude other acute diseases although there are no specific radiological signs of Ewing's sarcoma [8]. For this reason Ewing's sarcoma may initially be treated as GIST [7] as in our case.
To provide proper diagnosis, pathological examination should be carried out. It's round cell morphology is similar to neuroblastoma, malignant lymphoma, rhabdomyosarcoma, GIST, and desmoplastic small round cell tumour [14]. While Ewing's sarcoma shows rosette formation, glycogen deposition, also NSE, S-100 protein, neurosecretory-type granules [12]. In addition CD99 antigen could also be a useful tool [15]. Nowadays molecular testing is a reliable diagnostic method to diagnose ES. The most frequent translocation EWSR1-FLI1 occurs in 85% of cases of ES [2,22]. Second most common translocation is EWSR1-ERG (5-15%) and in such cases tumour cells are immunohistochemically positive for ERG marker. In our case ERG immunohistochemical reaction was positive, although there was no EWSR1-ERG translocation. However there is a very rare ERG-FUS translocation (< 1%), when tumour cells are also positive for ERG. We suppose that this translocation could occur in our case. It is also mentioned that fusion transcripts should not be the sole criterion of PNET [17].
All Ewing's sarcoma treatment includes local surgical and/or radiotherapy treatment followed by multidrug systemic chemotherapy [5,7]. It usually includes vincristine, doxorubicin, cyclophosphamide and dactinomycin [16] although of ifosfamide and etoposide were added. Latter improves outcomes in non-metastatic cases [13].
Prognosis of intestinal Ewing's sarcoma is not known as there are not enough cases. It could be compared to other sites. Although some authors do not relate tumour size with worse outcomes [13] other find > 5 cm size of the tumour having impact for worse survival [24]. Even in those cases surgical intervention is recommended as it decreases morbidity [21,25]. Worse survival also may include pelvic site, older patients, poor response to chemotherapy, and metastatic disease at presentation [8] which was in our case. The main two reasons of unfortunate consequence in our case was acute pancreatitis caused by R1 resection at the uncinated process and a very aggressive underlying disease.
To conclude, extraosseus Ewing's sarcoma is extremely rare entity, with most often poor prognosis. Availability of data and materials Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.