Low-Grade Chondrosarcoma of the Ilium in a 3-Year-Old Boy: a case report

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1 中華放射醫誌 Chin J Radiol 2009; 34: Low-Grade Chondrosarcoma of the Ilium in a 3-Year-Old Boy: a case report Chia-Jung Yang 1 Shin-Lin Shih 1,2 Fei-Shih Yang 1,3 Department of Radiology 1, Mackey Memorial Hospital Department of Radiology 2, Taipei Medical University Department of Radiological Technology 3, Yuanpei University Chondrosarcoma is very rare in children. We present a case of a 3-year-old boy with a pelvic chondrosarcoma incidentally discovered on a plain abdominal radiograph. Pelvic computed tomography (CT ) and magnet ic re sonance imaging (MRI) showed a lobulated bone tumor with chondroid components in the left iliac bone. The child underwent wide excision of the tumor. Pathology examination confirmed a final diagnosis of low-grade conventional chondrosarcoma. When a large mineralized tumor with a chondroid component involves the pelvic bone, chondrosarcoma should be considered in the differential diagnosis even in a child, despite the low incidence of the tumor in young children. To our knowledge, this is the first case report of CT and MRI evidence of a low-grade iliac chondrosarcoma in a patient under the age of 5 years. Reprint requests to: Dr. Shin-Lin Shih Department of Radiology, Mackey Memorial Hospital. No. 92, Sec. 2, Chung Shan N. Road, Taipei 104, Taiwan, R.O.C. Chondrosarcomas are malignant tumors of cartilaginous origin. They can arise as primary tumors or secondary to underlying neoplasms such as an enchondroma or osteochondroma. Conventional intramedullary chondrosarcoma is the most frequent primary type. It most commonly involves the femur, humerus, pelvis, scapula, or ribs, but rarely the neck or craniofacial region [1]. The incidence of chondrosarcoma peaks in the 30-to-60 year age range, with most tumors arising in patients older than 40. The reported incidence in the first or second decade of life is only 3.8% [2, 3]. We report an uncommon case of pelvic low-grade chondrosarcoma in a 3-year-old boy. CASE REPORT A previously healthy 3-year-old boy presented to the hospital with vomiting and loose stool for 3 days. The past history and physical examination were noncontributor y. A plain abdominal radiograph, ordered for evaluation of apparent gastroenteritis, incidentally showed a large tumor with a mixed osteolytic and osteosclerotic appearance involving the left iliac wing (Fig. 1). Pelvic computed tomography (CT) showed a mildly enhanced, expansile soft tissue mass about 3.0 X 3.2 X 4.7cm in size with endosteal scalloping of the cortex in the left iliac bone (Fig. 2). Pelvic magnetic resonance imaging (MRI) showed a left iliac tumor showing the similar signal intensities as the cartilages of bilateral hips joints and right iliac crest apophysis in all sequences which represented chondroid origin tumor (Fig. 3a-3d). The patient underwent wide excision of the tumor with a limb-sparing procedure. The pathology report was grade one conventional chondrosarcoma (Fig. 4a, 4b). There was no evidence of local recurrence on MRI one year after surgery, and the boy continued to do well when last seen more than 2 years after the operation.

2 136 Low-Grade condrosarcoma in a 3-year-old boy DISCUSSION The striking feature of this case is the young age of the patient. While the disease may be asymptomatic, it may also present with a palpable mass, pain, discomfort secondary to a mass effect, or a pathologic fracture [1, 4]. Conventional chondrosarcomas are usually large, generally greater than 4 cm in diameter [1]. Because the prognosis is better with lower-grade lesions, it is fortunate that our patient s chondrosarcoma was found incidentally at an early stage. These cartilage producing tumors are typically lobular, usually result in endosteal scalloping, and they sometimes erupt through the cortex and invade the soft tissue [4]. On plain films, conventional chondrosarcomas characteristically appears as a large expansile lesion in the long bones or pelvis with both osteosclerotic and osteolytic features, which is caused by chondroid matrix mineralization and bone destruction. CT scans may show lower attenuation of the nonmineralized component and chondroid mineralization. In our case, the plain radiograph showed the classic appearance of a large lobulated mass in the pelvis, and the CT scan demonstrated the characteristic endosteal scalloping of the cortex. MRI, however, is the best tool for assessing the intraosseous and soft-tissue extent of the tumor. The lesions usually have intermediate signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging. It is difficult to categorize the pathology type or grade radiologically. As seen in our case, low-grade conventional chondrosarcomas typically have widespread calcification which presents as low signal intensity on both T1-wieghted and T2-wieghted MR imaging. High grade lesions have less calcification and may extend into the soft tissue [1, 5]. The radiologic differential diagnosis in our Figure 1. Plain abdominal radiograph showing a large lobulated mass in the left iliac wing with mixed osteolytic and osteosclerotic features. 2a Figure 2. a. Contrast-enhanced abdominal CT showing a mildly-enhanced lobulated tumor with irregular bony erosion. b. In the bone window setting, endosteal scalloping of the cortex and faint intraosseous matrix mineralization are visible. 2b

3 Low-Grade condrosarcoma in a 3-year-old boy 137 3a 3b 3c 3d Figure 3. a. Coronal T1-weighted MR image 550/14 (TR/TE) showing the left pelvic mass has the same iso-signal intensity as the tri-radiate hyaline cartilages of bilateral hips. b. Axial T2-weighted MR image 3000/83 shows moderate high-signal intensity of the left pelvic mass. Areas of low-signal intensity of the tumor indicate calcifications. c. Coronal proton-density MR image 3716/26 shows massive cartilage component of the tumor without definite invasion to the adjacent structures. d. Axial gadolinium-enhanced T1-weighted MR image 550/14 with fat saturation demonstrates peripheral enhancement of the tumor. 4a Figure 4. a. Low-power photomicrograph (original magnification, X40; hematoxylin-eosin stain) shows bulky growth of the cartilage composed tumor with bone destruction and marrow infiltration. b. High-power photomicrograph (original magnification, X200; hematoxylin-eosin stain) demonstrates grade 1 conventional chondrosarcoma with enlarged nuclei with binucleate cells. 4b

4 138 Low-Grade condrosarcoma in a 3-year-old boy case included other cartilage-containing tumors such a s chond robla stoma a nd e nchond roma. Chondroblastoma is a rare benign bone tumor of cartilaginous origin, usually found in young patients, in which the tumor is typically small and arises in extra-axial bones [6]. Enchondroma is a common benign tumor which has been reported in the pelvic bones. Endosteal scalloping of enchondromas is usually less prominent than that seen in chondrosarcomas [1]. Chondrosarcomas are graded histologically from grade one, the slowest growing type, through grade four, with prognosis worsening as the grade increases [4, 7]. High-grade sarcomas are more likely to occur in older patients, with low-grade tumors more often seen in younger patients [8]. Gadwal et al. reported excellent long-term prognosis for pediatric patients with chondrosarcoma in the head and neck [9]. Complete surgical resection offers the chance of cure. Limb-sparing procedures are preferred in patients with low-grade chondrosarcoma in the pelvis or scapula. If wide excision is expected to result in morbidit y, int ralesional curettage, followed by phenolization or cryosurgery, and finally filling the cavity with bone graft can be considered. Radiotherapy is appropriate adjuvant therapy if resection is incomplete; it may be used for curative or palliative purpose. Based on current evidence, chemotherapy has no role in treatment of chondrosarcoma [7]. Given that our patient s tumor was low-grade histologically and was completely resected, he appears to have a very good prognosis. This case is a reminder that children can have chondrosarcomas, even though this tumor is much more commonly encountered in adults. The imaging characteristics appear to be similar, however, regardless of the patient s age. The diagnosis should certainly be considered in a pediatric patient who has a bone tumor with chondroid component. REFERENCES 1. Murphey MD, Walker EA, Wilson AJ, Kransdorf MJ, Temple HT, Gannon FH. From the archives of the AFIP: imaging of primary chondrosarcoma: radiologic-pathologic correlation. Radiographics 2003; 23: Barnes R, Catto M. Chondrosarcoma of bone. J Bone Joint Surg Br 1966; 48: Dahlin D. Bone Tumors: general aspects and data on 6221 cases, 3rd ed: Springfield, 1978: Bjoernsson J, McLeod R, Unni K, Ilstrup D, Pritchard D. Primary chondrosarcoma of long bones and limb girdles. Cancer 1998; 83: Varma D, Ayala A, Carrasco C, Guo S, Kumar R, Edeiken J. Chondrosarcoma: MR imaging with pathologic correlation. Radiographics 1992; 12: Geirnaerdt M, Hermans J, Bloem J, et al. Usefulness of radiography in differentiating enchondroma from central grade 1 chondrosarcoma. AJR Am J Roentgenol 1997; 169: Gelderblom H, Hogendoorn PC, Dijkstra SD, et al. The clinical approach towards chondrosarcoma. Oncologist 2008; 13: Lee FY, Mankin HJ, Fondren G, et al. Chondrosarcoma of bone: an assessment of outcome. J Bone Joint Surg Am 1999; 81: Gadwal SR, Fanburg-Smith JC, Gannon FH, Thompson LD. Primary chondrosarcoma of the head and neck in pediatric patients: a clinicopathologic study of 14 cases with a review of the literature. Cancer 2000; 88:

5 Low-Grade condrosarcoma in a 3-year-old boy 139 三歲男童左側腸骨的低度軟骨肉瘤 : 病例報告 楊家融 1 施焄鏻 1,2 楊斐適 1,3 台北馬偕紀念醫院放射線科 1 台北醫學大學放射線診斷科 2 元培科技大學放射技術系 3 軟骨肉瘤在兒童的發生率非常低 我們提出一位 3 歲男童, 在腸胃炎住院期間, 腹部素片意外發現左側腸骨軟骨肉瘤的案例 骨盆腔電腦斷層攝影及磁振造影顯示在左側腸骨有一個含有軟骨成分的多葉狀腫瘤 病患接受了腫瘤廣泛切除, 病理組織檢查的最終診斷為低度傳統軟骨肉瘤 即使一個兒童者, 在腸骨出現一個大型的礦化腫瘤, 並有軟骨成分時, 軟骨肉瘤應列入鑑別診斷中 據我們所知, 這是第一個包含電腦斷層攝影及磁振造影像, 討論五歲以下病患低度軟骨肉瘤的病例報告