Osteochondroma of 12th Thoracic Vertebra- A Case Report-

J Korean Soc Spine Surg. 2011 Jun;18(2):70-74.

doi: 10.4184/jkss.2011.18.2.70

Case Report

Received: April 19, 2011 Revised: April 26, 2011 Accepted: April 27, 2011 Published Online: June 30, 2011 Corresponding author: Jin-Young Lee MD

Department of Orthopedic Surgery, Kangdong Sacred Heart Hospital 445, Gil-dong, Kangdong-gu, Seoul 134-701, Korea

TEL: 82-2-2225-2706, FAX: 82-2-789-4391 E-mail: [email protected]

“This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://

creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.”

본 논문의 요지는 2010년도 대한정형외과학회 추계학술대회에서 학술전시 되 었음.

Osteochondroma of 12th Thoracic Vertebra - A Case Report-

Jin-Young Lee M.D., Kyung-Won Song M.D., Hyun-Jin Park M.D., Hyun-Tai Park M.D.

Department of Orthopedic Surgery, Kangdong Sacred Heart Hospital, Hallym University School of Medicine, Seoul, Korea

Study Design: Cases report

Objectives: We report 1 case of relatively rare osteochondroma that was in thoracic spine

Summary of Literature Review: Osteochondroma is one of the most common benign tumor in bone, consist of 40%, but, rare in spine area occupying only 2%. We report a case of osteochondroma that was in the 12th vertebra of thoracic spine, that had severe right flank pain. We performed en bloc excisional biopsy of the bony mass.

Materials and Methods: A fourty seven-year-old male complained right flank pain. He had mass of 12th thoracic costovertebral junction and underwent open excision and biopsy

Results: The preoperative pain disappeared and any signs of recurrence were not found on the follow up performed at 1 year.

Conclusions: The painful osteochondroma of thoracic spine is treated successfully by surgical technique.

Key Words: Thoracic spine, Osteochondroma

Osteochondroma is the most common tumor among benign bone tumors, and it accounts for approximately 40% of benign bone tumors.¹⁾ It has been reported that it occurs in the metaphysis of long bones, in other words, it occurs preferentially in the distal femur, the proximal tibia, the proximal humerus, etc., and among flat bones, the pelvic bone and the scapula. The lesion in the spine is approximately 2%, it is not common, and it develops rarely in the age groups who completed bone growth.²⁾ In clinics, it is difficult to diagnose only by plain radiography.

It should be diagnosed by computed tomography or magnetic resonance imaging in association with physical symptoms that are presented by patients. It requires the differential diagnosis from the herniation of intervertebral disc, spinal stenosis, etc.

The authors experienced a 47 years old male patient case who presented with the right flank pain caused by osteochondroma developed in the 12^th thoracic vertebra, it was removed surgically, and good results were obtained. The case thus is reported together with a review of the literature.

CASE REPORT

A 47 years old male patient visited our clinic for the chief complaint of the right flank pain developed incidentally from 2 months ago. In physical examination that was performed at the

time of visit, severe right flank pain was detected, nonetheless, tenderness was absent. In the right back area, pain that was restricted to the 12^th thoracic dermatome and the 1st lumbar dermatome was shown. In urine test, urologic and nephrologic examination, special findings were not observed. By plain radiography, in the costovertebral junction of the right 12^th thoracic vertebra, an oval bone tumor approximately 2.5 X 1.7 cm in size that was absent on the lumbar plain anteroposterior radiograph performed 4 years ago was detected (Fig. 1).

Computed tomography and magnetic resonance imaging were performed on the thoracic area. In computed tomography, high signal intensity that appears to be the enlargement, hypertrophy and scleroris of the costovertebral junction of the 12^th thoracic vertebra was shown. In magnetic resonance imaging, on T1 weighted axial view, similar to computed tomography, the finding of the hypertrophy of the 12^th thoracic vertebra was shown, and relatively regular low signal intensity was shown.

On T2 weighted axial images, a tumor that shows relatively even low signal intensity was observed, the border was relatively distinct, and the findings of the metastasis to adjacent soft tissues and bone tissues were not observed (Fig. 2).

In the collaborative test and diagnosis with the department of nephrology, the department of urology, and the department of dermatology, special findings and diseases were not detected. The pain showed a pattern that was restricted to the 12^th thoracic dermatome. By radiological test, a tumor in the costovertebral junction of the 12^th thoracic vertebra was observed, the pain was

diagnosed as symptoms of the consequent nerve compression, and open excision was performed.

By the open excision that was performed by posterior approach to the thoracic vertebra, a mass 3 X 2 X 2 cm in size with a distinct border was detected, and the 12^th thoracic spinal nerve was observed to be compressed. While protecting the spinal nerves from injury, using a bone cutter, the tumor was removed from the apex area of thoracic vertebra body including a portion of the 12th rib was removed. After the removal of tumor, free movements of the 12^th thoracic spinal nerve were confirmed, and soft tissues were sutured (Fig. 3).

Excision and biopsy was performed on osteochondroma that was developed in the 12th costovertebral junction. In pathological findings, the excised specimen was thick bone tissues containing cartilages of which surface was irregular and uneven. The results of the microscopic examination at 40 times magnification of the resected surface showed the findings of osteochondroma that it was mature normal bone tissues, Fig. 1. (A) Four years ago, anteroposterior radiography of lumbar spine of 47 years old man showed that 12th costovertebral junction was clear. (B) Bony mass which looks radioopeque is found on 12th costovertebral junction in pre operative state. Radiographs of the thoracic spine, anteroposterior view show sclerotic and hypertrophic bony mass density on the costovetebral junction of the 12^th thoracic vertebrae.

Jin-Young Lee et al Volume 18 • Number 2 • June 2011

surrounded by the cartilaginous cap, endochondral ossification was shown in some areas of the cartilages, and cancellous bones were formed beneath cartilaginous cap and atypical cells were not observed (Fig. 4).

Immediately after surgery, infection and other complication findings were not shown. Walking was allowed from 2 days after surgery, and suture was removed 2 weeks after surgery. The pain that was presented with prior to surgery was completely resolved 3 days after surgery, and during one year follow-up observation period, it did not recur.

DISCUSSION

Osteochondroma is a common tumor that accounts for 40%

of the entire benign bone tumors. Nonetheless, only 2% of them occur in the vertebra.²⁾ Osteochondroma is broadly classified to

solitary osteochondroma and multiple osteochondroma. It has been reported that approximately 14% osteochondromas are multiple, and approximately 75% of them are inherited in an autosomal dominant manner. The etiology of osteochondroma is not clear, nevertheless, it is thought to be originated from the separation of epiphyseal growth plate cells through the periosteum surrounding the growth plate.³⁾ In regard to the predilection site osteochondroma, approximately 30%

occur in the long bones, particularly the knee joint and the upper humerus, and approximately 12% occur in the pelvis, the scapula, and the costa. It rarely occurs in the vertebra.⁴⁾ Osteochondroma has a tendency to grow slightly away from the articular surface. The onset age is the teens or the infant period preferentially, and it is rare after the completion of bone growth.

The cause has not been elucidated, nevertheless, it has been hypothesized that pathologically accelerated bone turnover in Fig. 3. (A) Intra operative photography shows that 12^th thoracic nerve root is decompressed by excision of the mass occupied costovertebral junction space. (B) 3 X 2 X 2 cm sized oval shaped, irregular surfaced osteochondroma protruding posteriorly from the 12th thoracic vertebrae is removed.

Fig. 2. (A) Axial computed tomography scan of the patient shows the osteochondroma protruding posteriorlaterally from the costovertebral junction of 12^th thoracic vertebra. We can find more hyperplastic costovertebral junction in Rt side than Lt which is normal. (B) MRI image. T1 weighted image. (C) T2 weighted image. In the thoracic MRI, it shows a irregular margined, well-circumscribed ossified mass lesion, from right side of 12^th thoracic vertebra on (B) T1 axial image and (C) T2 axial image.

been elucidated. Nevertheless, it has been shown that it occurs approximately 1.5 times more in the male than the female.⁵⁾ The mean age of 60% patients who developed osteochondroma in the vertebra was younger than 20 years, and it occurs more frequently in the male.⁶⁾ Typically, in the vertebra, it occurs in the posterior factors particularly, the tip of spinous process, and it invades more than 2 spinal bodies.⁷⁾ According to the study reported by Albercht et al., 49% osteochondroma developed in the vertebra occur in the cervical vertebra, 26% in the thoracic vertebra, and 23% in the lumbar vertebra.¹⁾

Concerning clinical symptoms of osteochondroma, although it may be found incidentally by radiological findings, the major symptom is the palpation of a painless lump, and occasionally, pain that is associated with mechanical compression, nerve compression, fracture of the stalk of tumor, malignant degeneration, osteomyelitis, pseudoaneurysm and bursitis may be present.⁴⁾ The symptoms of osteochondroma that is developed in the vertebra are proportional to the size of tumor, and the major symptoms are caused by nerve compression and the compression of other adjacent organs. Nevertheless, cases associated with neurological symptoms are very rare because most lesions do not invade the spinal canal. However, in our case, although the lesion was present in the outside of the spinal canal, neurological symptoms similar to far lateral disc herniation were associated.

In plain radiological test, osteochondroma is detected as a

method for the diagnosis of osteochondroma. The findings are irregular, and a mass with a border distinct from the cortex and the bone marrow continuous to normal bones that is covered with cartilaginous cap could be observed. Pathologically, osteochondroma is shown as irregular bony masses with the gray white cartilaginous cap. Histologically, it has hyaline cartilages and mature bony spurs.

Considering that the probability of osteochondroma converting to malignancy is less than 1%, the principle of the treatment for osteochondroma is observation generally. Nonetheless, because of appearance, dysfunction of adjacent tissues, cases caused by the fracture of the stalk of tumor, symptoms of nerve compression, malignant degeneration is suspected, or diagnosis is vague, they become indication of surgical removal.

Macgee⁹⁾ has reported 1 case which occurred in the lamina of the vertebral arch of 2nd cervical vertebra and caused temporary quadriplagia, and if osteochondroma is benign histologically but with neurological symptoms due to nerve compression, by early diagnosis and surgical removal, good results could be obtained.

Fig. 4. On low magnitude power, section shows thickened bone and cartilage fragment. The mature bone is covered with well-differentiated osteocartilaginous cap. Also, there is endochondral ossification (H&E, x40).

Fig. 5. After operation, there is no more abnormal radioopaque findings of osteochondroma from the costovertebral junction of 12^th thoracic vertebra.

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Madigan et al.¹⁰⁾ have reported in a review of the literature that for 12 cases of osteochondroma which compressed the nerve in the cervical vertebra and the thoracic vertebra and thus caused neurological symptoms, laminectomy and tumor resection were performed and neurological symptoms were recovered.

In vertebral compression caused by osteochondroma, if the vertebra is decompressed by completely resecting the tumor, good recovery of neurological symptoms could be anticipated.

For osteochondroma that was originated from the outside of the spinal canal as our case, nonetheless, it occurred in the distal lateral area and thus showing neurological symptoms similar to the herniated nucleus pulposus, the principle is surgical treatments. In our case, together with the improvement of symptoms after surgery, good results without recurrence of 1 year follow-up observation were obtained.

CONCLUSIOS

The authors treated a rare case of osteochondroma that was developed in the 12^th thoracic vertebra by surgical removal and good results were obtained, and thus the case was reported together with a review of the literature.

REFERENCES

1. Albrecht S, Crutchfield JS, SeGall GK. On spinal osteochondromas. J Neurosurg. 1992;77:247-52.

2. Yagi M, Ninomiya K, Kihara M, Horiuchi Y. Symptomatic osteochondroma of the spine in elderly patients. J Neurosurg Spine. 2009; 11:64–70

3. Cooke RS, Cumming WJ, Cowie RA. Osteochondroma of the cervical spine: case report and review of the literature. Br J Neurosurg. 1994;8:359-63.

4. Chung SS, Lee JS, Kim DJ, Moon SH, Yoon TH.

Osteochondroma of the Cervical Spine: A Case Report. J Korean Orthop Assoc. 2004;39:833-6.

5. Bullough PG. In. Orthopedic Pathology. 3rd ed. London : Mosby-Wolfe. 1997;1:354-6.

6. Dahlin DC, Unni KK. In. Bone Tumors: General Aspects and Data on 11,087 cases 5th ed. Springfield, IL:

Lippincott-Raven. 1996;1:11-25.

7. Malat I, Virapongse C, Levine A. Solitary osteochondroma of the spine. Spine (Phila Pa 1976). 1986;11:625-8.

8. Huvos AG. Bone tumors, Diagnosis Treatment and Prognosis. 2nd ed. Philadelphia, W.B. Ssunders Co., 1991.

9. MacGee EE. Osteochondroma of the cervical spine: a cause of transient quadriplegia. Neurosurgery. 1979;4:259-60.

10. Madigan R, Worrall T, McClain EJ. Cervical cord compression in hereditary multiple exostosis: Review of the literature and report of a case. J Bone Joint Surg Am.

1974;56:401-4.

제 12 흉추 추체에 발생한 골연골종 - 1예 보고 -

이진영 • 송경원 • 박현진 • 박현태 한림대학교 강동성심병원 정형외과학교실

연구 계획: 증례 보고

목적: 비교적 보기 드문 척추에서의 골연골종 1예를 경험하였기에 보고하고자 한다.

선행문헌의 요약: 골연골종은 골종양 중 가장 흔한 양성 종양으로, 양성 골종양의 40%를 차지하고 있으나, 척추에서의 병변은 2%에 지나지 않는다. 저 자들은 제 12번 척추 신경 부위의 통증을 동반한 제 12 흉추에 발생한 골연골종 1예를 en bloc을 통한 절제 생검을 시행하였다.

대상 및 방법: 47세 남자 내원 2달 전부터 발생한 우측 측복통을 주소로 내원하여 흉추 12번의 늑골척추 관절 부위에 종괴가 관찰되어 개방적 절제술과 절개 생검을 시행하였다.

결과: 술 전에 호소하였던 동통은 완전히 소실되었으며, 수술 후 1년간 추시 동안 재발은 없었다.

결론: 제 12 흉추에서 기인한 골연골종을 수술적 제거술로 치료하여 좋은 결과를 얻었다.

색인 단어: 흉추, 골연골종 약칭 제목: 제 12 흉추 골연골종