Leiomyosarcoma arising from the inferior mesenteric vein

Abstract

Leyomiosarcomas arising from the portal/mesenteric venous system are very rare tumours, and only a few cases have been reported in the global literature. As the other leyomiosarcomas of vascular origin, they are associated with a poor prognosis. The present report describes the case of a 66-year-old woman with a leyomiosarcoma of the inferior mesenteric vein, unexpectedly found during a CT scan performed for another indication. A brief review of the literature is also given. The patient underwent radical surgical excision and enjoys a good health, without radiological signs of recurrence, 24 months after surgery. In this case, an early incidental diagnosis determined an early treatment and, probably, a favourable prognosis. This is the second case of leyomiosarcoma of the inferior mesenteric vein reported in the literature.

BACKGROUND

Leyomiosarcomas (LMSs) of vascular origin are rare tumours and usually arise from the inferior vena cava or major veins of the extremities.¹ LMSs arising from the portal/mesenteric venous system are very rare tumours, and review of the literature revealed only a few prior reports. We present a case of LMS, arising from the inferior mesenteric vein (IMV), treated at our unit.

CASE PRESENTATION

A 66-year-old woman presented with left lower abdominal pain, nausea and fever. She had a history of diverticular disease of the left colon. Physical examination revealed tenderness at the level of the left lower abdomen without palpable mass. Her white blood cell count was 14 000/mm³. A diagnosis of sigmoid diverticulitis was made on the basis of the clinical signs and the patient was treated conservatively with fluids and antibiotics administration. An abdominal CT scan was performed: it confirmed the diagnosis of sigmoid diverticulitis and revealed a round, heterogeneous, contrast-enhancing mass in the retroperitoneum (fig 1A). The retroperitoneal mass appeared well marginated, with high signal-intensity spots and a circular focus of signal void on axial T2-weighted MRI studies (fig 1B). The symptoms of sigmoid diverticulitis disappeared after few days with treatment and the patient underwent surgery 1 month later. After mobilisation of the left colon, the mass was noted to arise from the inferior mesenteric vein. Previous to proximal and distal control, a segmental resection of the vein, including the mass, was made (fig 2). A left colonic resection was also accomplished and the postoperative course was uneventful. Histological examination of the mass revealed a LMS arising from the IMV. The patient received a course of external beam radiation therapy.

Figure 1.

A. CT scan showing a round, contrast-enhancing mass in the retroperitoneum. B. T2-weighted MRI showing a well marginated mass; the circular focus of signal void indicates a vessel embedded in the tumour.

Figure 2.

surgical specimen and histological appearance of the leiomyosarcoma (LMS) of the inferior mesenteric vein (IMV).

OUTCOME AND FOLLOW-UP

At 24 months after surgery, the patient enjoys a good health without radiological signs of recurrence.

DISCUSSION

LMSs arising from the portal/mesenteric venous system are very rare tumours and only a few cases have been previously reported. In 1947, a LMS arising from the inferior left colic vein was resected by Puig Sureda et al² in a 61-year-old woman. In 1976, Choquart et al³ reported a case of LMS of the IMV in a 83-year-old woman; the patient underwent surgical excision of the mass, but 12 months later she developed pulmonary metastases. In 1987, Wilson and Hine⁴ reported a large (10 cm), asymptomatic but unresectable LMS of the portal vein in a 28-year-old woman. In 1995, a case of LMS involving the portal vein was reported by Madariaga et al.⁵ In a surgical first at the time, a mesocaval shunt was accomplished for a portal hypertension precluding resection; 6 months later, the mass was removed but patient quickly developed liver metastases. More recently, four cases of LMSs of the superior mesenteric vein were reported by Goldin et al,¹ Celdràn et al,⁶ Leporrier et al⁷ and Kuma et al.⁸ The patients were, respectively, a 40-year-old woman, a 66-year-old man, a 50-year-old woman and a 62-year-old woman. In the first and second cases a resection of the vein with a saphenous vein interposition graft was accomplished; the third case underwent a Whipple procedure with revascularisation by a GoreTex prosthesis; the fourth case underwent a tumour resection with venous reconstruction, right hemicolectomy and right hepatic lobectomy. The 40-year-old woman reported by Goldin et al⁵ developed a solitary liver metastasis 6 months after primary procedure and underwent liver resection. The second and the third patient did well.^6,7 The fourth patient survived for about 3 years.⁸ Since the tumour was positive for c-kit (CD117), 8 months after surgery the patient received chemotherapy with imatinib mesylate after detection of multiple metastatic nodules in the left hepatic lobe.

All the reported patients were symptomatic for abdominal pain and weight loss, with the exception of the two patients reported by Wilson and Hine⁴ and by Kuma.⁸

LMSs of the portal venous system are associated with as poor a prognosis as other LMSs of vascular origin. They occur predominantly in women; a single case has been reported in a man.⁶ Surgical excision represents the treatment of choice. External postoperative radiotherapy is frequently used, and is sometimes associated with various combinations of chemotherapeutic agents. Nevertheless, there is no evidence that adjuvant therapies improve survival.¹ In our patient, the second case of LMS of the IMV reported in the literature, LMS was an incidental finding during a CT scan performed for another indication. Hence an early incidental diagnosis determined an early treatment and, probably, a favourable prognosis.

LEARNING POINTS

• Leyomiosarcomas (LMSs) of vascular origin are rare tumours and usually arise from the inferior vena cava or major veins of the extremities.

• LMSs of the portal venous system are associated with as poor a prognosis as other LMSs of vascular origin.

• Surgical excision represents the treatment of choice.