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 Table of Contents  
Year : 2013  |  Volume : 10  |  Issue : 2  |  Page : 95-97

Primary mesenteric extraskeletal osteosarcoma

1 Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
2 Department of Surgery, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria

Date of Web Publication7-Dec-2013

Correspondence Address:
S A Ahmed
Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria - 810 001
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0331-8540.122772

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Extraskeletal osteosarcoma (EOS) is a rare malignant soft tissue tumor. It predominantly occurs in the extremities, and is highly aggressive and rarely involves the visceral organs. Only five cases of mesenteric EOS have been reported in English literature. We describe a male patient of 56 years, who was diagnosed to have EOS arising from small bowel mesentery. Literature search and review was made. This patient presented with lower gastrointestinal bleeding. Resection of the tumor with adjacent small bowel was performed. Histopathology was performed and it revealed an osteosarcoma of mesentery. Given the rarity of cases of mesenteric EOS, its biologic behavior at this location remains to be determined. There should be high index of suspicion because of the possible fatal outcome related to the tumor. EOS has a very poor prognosis and a promising therapeutic regimen does not exist.

Keywords: Extraosseous, mesenteric, mesentery, osteogenic sarcoma

How to cite this article:
Ahmed S A, Mohammed U, Garba E S, Calvin B, Shehu M S. Primary mesenteric extraskeletal osteosarcoma. Niger J Basic Clin Sci 2013;10:95-7

How to cite this URL:
Ahmed S A, Mohammed U, Garba E S, Calvin B, Shehu M S. Primary mesenteric extraskeletal osteosarcoma. Niger J Basic Clin Sci [serial online] 2013 [cited 2023 Jun 1];10:95-7. Available from: https://www.njbcs.net/text.asp?2013/10/2/95/122772

  Introduction Top

Extraskeletal osteosarcoma (EOS) is a malignant mesenchymal neoplasm that produces osteoid, bone, or chondroid material and is located in the soft tissue without attachment to the skeleton as determined by imaging modalities or inspection during surgical operative procedure. [1] EOS is a rare type of tumor making up only 1% of all soft tissue sarcomas and 4% of all osteosarcomas. [2],[3],[4],[5] The tumor is most common in middle-aged and elderly patients. The common sites of involvement are deep soft tissue of thigh (47%), upper extremity (20%), and retroperitoneum (17%). [4],[6] It rarely involves the intraperitoneal visceral organs. Only five cases of mesenteric EOS have been reported in the English literature. [5],[6],[7],[8],[9] And to the best of our knowledge, this is the first case report of mesenteric EOS in Nigeria. The single most important criteria for diagnosis of this tumor is presence of neoplastic osteoid and bone; sometimes with neoplastic cartilage. [1],[2],[5] The histological variants of EOS include osteoblastic, chondroblastic, fibroblastic, giant cell type, telangiectatic, small cell, or well differentiated forms. [2] Closely related differentials include calcified hematoma, myositis ossificans, synovial sarcoma, epithelial sarcoma, liposarcoma, or malignant fibrous histiocytoma. [1],[2],[5]

  Case Report Top

A 56-year-old civil servant presented with 2 years history of lower abdominal pain and two episodes of hematochezia for 6 months. He was relatively well before the 2-year history of pain. The bloody stool episodes were 6 and 4 months before presentation to the hospital. The pain was not severe to warrant any form of medication. He however noticed a swelling in the right groin 2 months before presentation which was initially reducible, but became incarcerated 2 days before presenting to the hospital. He had abdominal swelling, abdominal pain, vomiting, and constipation. No other important past medical history and history of surgery or trauma. On examination, he was in painful distress, dehydrated, not pale, no pedal edema, and no jaundice. Chest and cardiovascular system (CVS) were stable, blood pressure (BP) was 145/90 mmHg, and pulse rate was 86 beat/min. The main finding was abdominal distension with visible peristalsis. No tenderness except over the inguinal swelling or organ enlargement; and rectal examination was normal. A diagnosis of intestinal obstruction was made secondary to irreducible inguinal hernia. Had urea and electrolyte with hemogram (hemoglobin (HB) of 14.5 g/dl) which were normal. Computed tomography (CT) scan and/or magnetic resonance imaging (MRI) was not done due to nonavailability of service when the patient presented. At surgery, he had a mass attached to the ileum and pushing and causing luminal obstruction with ischemia of the ileum. He had resection of the ischemic portion and the ileum was reestablished by anastomosis. Cut-section of the mass showed grey-white solid area with gritty sensation and hemorrhagic areas [Figure 1]. The histopathology revealed an osteoblastic variant of osteosarcoma of the mesentery [Figure 2]. The patient was doing well and was seen once post operatively; however, he was lost to follow-up.
Figure 1: Cut-section of the bowel showing solid grey white tumor

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Figure 2: Tumor showing malignant cells depositing osteoid (H and E, ×100)

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  Discussion Top

We present a rare case of an EOS of the mesentery in a 56-year-old patient who initially presented with abdominal pain. Extraskeletal or soft-tissue osteosarcomas are rare, accounting for less than 1% of all soft-tissue sarcomas and 4% of all osteosarcomas. Primary osteosarcomas of bone occur predominantly in the first decades of life, and less frequently as secondary osteosarcomas at higher age. Usually, EOS has peak prevalence in patients at the 6 th decade of life, and men are slightly more frequently affected, with a ratio of 1.9:1. [5],[7],[10] Our patient was a male, in sixth decade, as the described age in the literature. The clinical presentation of our patient with gastrointestinal (GI) bleeding was almost similar with the case reported by Lee et al., and Hussain et al. [3],[7] CT Scan and/or MRI service was not available when the patient presented, this is a challenge in the management of this patient. Symptoms often include a slow growing painful mass that is visible on plain radiographs, CT, and MRI. Radiologic studies typically show large soft-tissue masses with focal to massive areas of mineralization and lack of osseous involvement. [4],[5],[7] However, other soft tissue sarcomas and carcinoma can also present with significant area of calcification and thus histologic biopsy is required to establish the definite diagnosis. Based on the excessive production of malignant osteoid, appearance of osteoblast-like tumor cells and exclusion of other sarcomatous differentiation, EOS was diagnosed. On immunohistochemical studies, paraffin-embedded tissue using heat method of antigen retrieval method. The neoplastic cells were positive for vimentin [Figure 3]; but negative for cytokeratin, epithelial membrane antigen, desmin, and CD34. The final histologic diagnosis was a mesenteric EOS. The immunohistochemical findings are similar with the cases reported in other studies. [1],[5],[8]
Figure 3: Neoplastic cells were positive for vimentin (H and E, x40)

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The pathogenesis of the tumor is unclear. Cases usually arise de novo, and no precursor lesions are known. The tumor may occur and be induced at sites that have received previous radiotherapy. Radiation-induced EOS usually develops at least 4 years following high-dose radiation. [3],[4],[5] In addition, a history of trauma has been reported in 12-30% of patients, and cases have been described in which EOS is presumed to be preceded by myositis ossificans lesions. [3],[4],[5],[7] However, in our case, there was no history of radiation or trauma. EOS arising from diverse locations such as cerebellum, kidney, urinary bladder, liver, mesentery, parotid, uterus, larynx, and gallbladder have been reported. [5],[11] Only five cases of mesenteric EOS have been reported in the English literature. [5],[6],[7],[8],[9]

To our knowledge, this is the first description of EOS in the small bowel mesentery in Nigeria.

EOS has poor prognosis, and approximately 75% of the patients die of the disease within 5 years of diagnosis. [4],[7],[10] Local recurrence develops in approximately one-third of the patients and pulmonary metastasis in 60%. [7] Tumor size is the most important prognostic factor, as the patients with a lesion larger than 5 cm have a worse clinical outcome. Other poor prognostic factors include the presence of metastatic lesion, patient age, and increased lactate dehydrogenase and alkaline phosphatase level. [4],[7],[9],[11] Our patient with mass but no metastasis and is alive. All major subtype of primary osteosarcoma can also be found in EOS. The most common is the osteoblastic variant, followed by fibroblast, chondroblastic, telangiectatic, small cell, and well-differentiated type. [7],[9] Wide resection followed by adjuvant chemotherapy and radiotherapy is the available mode of management for these patients.

  Conclusion Top

EOS can involve the peritoneum and should be considered in the differential diagnosis of mesenchymal tumors of the abdominal cavity. There should be high index of suspicion because of the possible fatal outcome related to the tumor. EOS, regardless of its site of origin has a very poor prognosis and currently lacks a promising therapeutic regimen.

  References Top

1.Weiss SW, Goldblum J. Osseous soft tissue tumours. In: Enzinger and Weiss; Soft Tissue Tumours, 4 th ed. St Loius: Mosby; 2001. p. 1389-417.  Back to cited text no. 1
2.Temitope OA, Henry AO, Gabriel OO. Extraosseous osteosarcoma in Ibadan: Case series over a 20-year period. Rare Tumours 2009;1:6-8.  Back to cited text no. 2
3.Lee JS, Fetsch JF, Wasdhal DA, Lee BP, Pritchard DJ, Nascimento AG. A review of 40 patients with extraskeletal osteosarcoma. Cancer 1995;76:2253-9.  Back to cited text no. 3
4.Chung EB, Enzinger FM. Extraskeletal osteosarcoma. Cancer 1987;60:1132-42.  Back to cited text no. 4
5.Heukamp LC, Knoblich A, Rausch E, Friedrichs N, Schildhaus HU, Kahl P, et al. Extraosseous osteosarcoma arising from the small intestinal mesentery. Pathol Res Pract 2007;203:473-7.  Back to cited text no. 5
6.Shirazi PH, Rayudu GV, Fordham EW. Exraosseous osteogenic sarcoma of the small bowel demonstrated by 18F scanning. J Nucl Med 1973;14:295-6.  Back to cited text no. 6
7.Hussain MI, Al-Akeely MH, Alam Mk, Jasser NA. Extraskeletal osteosarcoma, telangiectatic variant arising from the small bowel mesentery. Saudi Med J 2011;32:958-61.  Back to cited text no. 7
8.Lee KH, Joo JK, Kim DY, Lee JS, Choi C, Lee JH. Mesenteric extraskeletal osteosarcoma with telangiectatic features: A case report. BMC Cancer 2007;7:82.  Back to cited text no. 8
9.Choudur HN, Munk PL, Nielson TO, Ryan AG. Primary mesenteric extraskeletal osteosarcoma in the pelvic cavity. Skeletal Radiol 2005;34:649-52.  Back to cited text no. 9
10.Sordillo PP, Hajdu SI, Magill GB, Golbey RB. Extraosseous osteogenic sarcoma. A review of 48 patients. Cancer 1983;51:727-34.  Back to cited text no. 10
11.Bane BL, Evans HL, Ro JY, Carrasco CH, Grignon DJ, Benjamin RS, et al. Extraskeletal osteosarcoma. A clinicopathologic review of 26 cases. Cancer 1990;66:2762-70.  Back to cited text no. 11


  [Figure 1], [Figure 2], [Figure 3]

This article has been cited by
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