A. ADAIR, S.A. HARRIS, M.J. COPPEN and P.R. HURLEY
Department of Surgery, Mayday University Hospital, Croydon, U.K.
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Extraskeletal Ewings sarcoma is a tumour of neuroectodermal origin sharing close similarities with Ewings sarcoma of bone.We report the case of a 21 year old 16 week pregnant woman presenting with vomiting and weight loss and found to have an extraskeletal Ewings sarcoma of the small bowel.In a review of the literature there are no previous reports of extraskeletal Ewings sarcoma occurring in the small bowel. The diagnosis of extraskeletal Ewings sarcoma and the complicated management of a young pregnant woman with a malignant tumour are described.
Keywords: extraskeletal Ewings sarcoma, small bowel, pregnancy
J.R.Coll.Surg.Edinb., 46, December 2001, 372-374
Extraskeletal Ewings sarcoma (otherwise known as primitive neuroectodermal tumour - PNET) is a rare, highly aggressive malignant soft tissue tumour that shares close histological, immunohistochemical and cytogenetic similarities with the more common Ewings sarcoma of bone.1 We report for the first time its involvement in the small bowel, where the diagnosis and management were complicated by coexisting pregnancy.
A 21-year-old woman in the 16th week of her third pregnancy presented as an emergency with a four-day history of vomiting and generalised abdominal pain. She also described increasing difficulty in tolerating food for the previous three months, and a significant weight loss (10kg). A provisional diagnosis of hyperemesis was made, and her symptoms settled rapidly with conservative management. She was subsequently readmitted with mild acute renal failure caused by intractable vomiting. An oesophagogastroduodenoscopy showed an ulcerating, obstructing lesion in the third part of the duodenum. Endoscopic biopsies confirmed infiltration of the duodenum by a malignant small cell neoplasm, with features consistent with PNET. The patient was counselled, and the tumour was staged. Magnetic resonance imaging showed a large lesion arising from the duodeno-jejunal flexure involving both the small bowel and the surrounding tissue (Figure 1). However, there was no evidence of distal metastatic spread. Computerised tomography (CT) supported these findings and suggested the appearance to be that of an intussuscepting tumour (Figure 2).
Figure 1: Magnetic resonance imaging showing
a
Figure 2: Computerised tomography image
large lesion arising from the duodeno-jejunal
flexure
indicating an intussuscepting tumour
After counselling, the patient decided to undergo a combined procedure whereby the pregnancy would be terminated at the time of laparotomy. During the termination of the pregnancy, the patient suffered uncontrollable uterine bleeding that necessitated hysterectomy.
At operation, the macroscopic absence of metastatic spread was confirmed. A large tumour was present in the proximal jejunum and a radical, segmental small bowel resection was carried out with primary end-to-end anastomosis. Macroscopic examination of the operative specimen revealed a 26cm length of duodenum and proximal jejunum containing an ulcerating tumour (6 x 6 x 4cm) that appeared to infiltrate the full thickness of small bowel wall. Histological examination showed a malignant tumour of small rounded cells in anastamosing nests infiltrating the wall of the bowel and underlying mesentery (Figure 3). Resection margins and all resected lymph nodes were free of tumour involvement. Immunohistochemstry showed membranous staining for MIC2 (CD99), and focal dot like presence of CAM5.2, but not for desmin, MNF116, neurofilament, senatophycin or S100 protein. Neuron specific endolase was also demonstrated. These immunohistochemical appearances were entirely consistent with extraskeletal Ewings sarcoma/PNET. 2-5
After an uncomplicated post-operative course, the patient was referred for chemotherapy. Ten months following surgery she remains disease-free with no evidence of recurrence on CT scanning. She is continuing her course of chemotherapy treatment.
Further investigation into the family history revealed that a cousin of the patient had been previously diagnosed as having skeletal Ewings sarcoma.
Figure 3: Malignant tumour of small rounded cells in anastamosing nests infiltrating the wall of the bowel and underlying mesentery
Ewings sarcomas are bone and soft tissue tumours of neuroectodermal origin.1 Electron microscopy supports the close
similarity between skeletal Ewings sarcoma and extraskeletal
Ewings sarcoma/PNET. Histological assessment shows that
these tumours are composed of sheets of small rounded cells
with hyperchromatic nuclei, and scanty cytoplasm.1
Immunohistochemically, a number of markers have been
used, of which MIC2 (CD99) is particularly useful in eliciting
membranous positive staining of tumour cells. 2,3
Cytogenetically, there is a chromosomal abnormality, with
translocation of t (11:22) (q24:q12) being detected in 85% of
cases using standard cytogenetic techniques, and in up to 95%
of cases using reverse transcriptase and PCR. 2-5
PNET may occur at almost any age but, has a peak incidence predominantly in the second and third decades.6 There are no established predisposing, or genetic factors associated with PNET although there are anecdotal associations: in one case the sibling of a patient died of Ewings sarcoma of bone and in another the mother of the patient was treated for oesteosar-coma of tibia and myxoid liposarcoma of retroperitoneum.7 PNET generally presents as a rapidly growing, deeply located mass that tends to metastasise early in the course of the dis-ease. For this reason, although local control can be attempted with surgery and radiotherapy, PNET invariable requires systemic chemotherapy.1
PNET has been reported at a number of extraskeletal sites, the most common being the paravertebral region, chest wall, lower extremities and retroperitoneum.3,4 The most common organ-based location is the kidney but other sites include ovaries, uterus, abdominal cavity/peritoneum and lung. 3,4,6,7 We believe the above case to be the first description of an extraskeletal Ewings sarcoma originating in the small bowel.
Extraskeletal Ewings sarcomas are a rare group of malignant tumours carrying a poor prognosis despite aggressive treat-ment. The case we have presented illustrates the difficulty in diagnosis and management of malignant tumours presenting in young pregnant women.
1. Granowetter L. Ewings sarcoma and extracranial neuroectodermal tumours. Curr Opin Oncol 1996; 8: 305-10
2. Kawauchi S, Fukuda T, Miyamoto S, Yoshioka J, Shitshasms S, Saito T, Tsukamoto N. Peripheral primitive neuroectodermal tumour of the ovary confirmed by
CD99 immunostaining, karyotypic analysis and RTPCR
for EWS/fl-1 chimeric mRNA. Am J Surg Pathol 1998;
22: 1417-22
3. Katz RL, Quezado M, Senderowicz AM, Villalba L,Laskin WB, Tsoko M. An intra-abdominal round cell
neoplasm with features of primitive neuroectodermal and
desmoplastic round cell tumour and a EWS/FL-1 fusion
transcript. Hum Pathol 1997; 28; 502-9
4. Marley EF, Liapis H, Humphrey PA, RB, Siege MD, Zhu X, Brandt JM, Dehner LP. Primitive neuroectodermal
tumour of the kidney-Another enigma: A pathologic
immunohistochemical and molecular diagnostic study.
Am J Surg Pathol 1997; 21: 354-9
5. Cenacch G, Pasquinelli G, Montanaro L, Cerasoli S, Vici M, Bisceglia M, Giangaspero F, Martinelli GN,
Derenzini M. Primary endocervical extraosseous Ewings
Sarcoma/PNET. Int J Gynaecol Pathol 1998; 17: 83-88
6. Amin HM, Candel AG, Husain AN. A 22 year old man
with an abdominal mass. Arch Pathol Lab Med 1999;
123: 141-3
7. Enzinger FM., Sharon Weiss. Soft Tissue Tumours 108, 801-8. CV Mosby Company 1983
Copyright date: 31st July 2001
Correspondence: A. Adair, c/o Mr Hurley, Department of Surgery,
Mayday University Hospital, London Road, Thornton Heath, Croydon, Surrey CR7 7YE, U.K.
E-mail: nickadair@appleonline.net
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