Ossifying fibroma of the thoracolumbar spine: A case report and review of the literature

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Ossifying Fibroma of the Thoracolumbar Spine : A Case Report and Review of the Literature Takashiro Ohyama, M .D., Susumu Ohara, M .D., Fumiyuki Momma, M .D., Atsufumi Moto, M.D ., and Yasuo Nakata, M .D . Department of Neurosurgcry, Yao Tokushukai Hospital, Osaka, Japan, and the First Department of Pathology, Hyogo Medical College, Hyogo, Japan

Ohyama T, Ohara S, Momma F, Moto A, Nakata Y . Ossifying fibroma of the thoracolumbar spine : a case report and review of the literature . Sutg Neural 1992 ;37 :23 t-5 . A 43-year-old woman with ossifying fibroma of the thoracolumbar vertebrae was presented with a 6-month history of progressive radiculomyelopathy . The symptoms were successfully treated by laminectomy and partial resection of the lesion . This is the first reported case of ossifying fibroma involving the thoracolumbar spine . The clinical significance and management of this rare lesion are discussed with a review of the literature . KEY WORD :

Ossifying fibroma

Case Report A 43-year-old nurse developed back pain, dullness of both legs, and gait disturbance from the beginning of July 1989 . She also complained of a tingling sensation below the umbilicus that affected the left leg primarily with numbness when she bathed her leg. She also suffered from frequent urinary tract infections . Examination

Neurological examination revealed decreased pinprick sensation below the Tl2" dermatome on the left, slight weakness of the left extensor hallucis longus muscle, and eversion of the left foot . The deep tendon reflexes were normal bilaterally . The findings of a rectal examination were negative . She had normal urodynamic test results, although she suffered from frequent urinary tract infections . A hard tumor was palpable at the thoracolumbar region with mild tenderness . No visible abnormality was noted . Address reprint requests to :Takashi

ro Ohyama, M .D . . 0729-93-8501, Kyuhoji, Yao City, Osaka 581,

Yao Tokushukai Hospital, 3-15-38 Japan . Received May 1, 1991 : accepted October s; 1092 by Glsevier Science Publishing C-, Inc

4, 1991,

Spinal x-ray films showed bulging of the T12 and LI vertebral columns (Figure 1) . A bone scan and gallium scintigram showed abnormal uptake at the thoracolumbar junction (Figure 2) . A computed tomography (CT) scan demonstrated hyperostosis involving the left T12 and LI laminae and pedicles (Figure 3) . Magnetic resonance imaging displayed a slightly mottled hyperintensity lesion surrounded by a low signal intensity area both on T1- and T2-weighted images, indicating fatty degeneration of the tumor (Figure 4) . The tumor was not enhanced by gadolinium diethylene-triamine-pentaacidic acid (Figure 5) . A myelogram and CT scan also demonstrated a bony, dense lesion on the left side of the T12 and Ll laminae, pushing the dural sac to the right (Figures 6 and 7) . A preoperative urodynamic study showed normal sphincter function . Spinal angiography showed no abnormality of the vascular supply to the tumor . The great radicular artery of Adamkiewicz was derived from the left T12 subcostal artery (Figure 8) .

Operation

Laminectomy through T11 to Ll was performed and the bony tumor was excised to allow decompression of the spinal cord and left Tl I and T12 nerve roots . The tumor was thick and hard . The surrounding fatty tissue was partially excised . A left T12 and Ll foraminotomy was also performed to complete the decompression of the roots . Great care was taken to preserve the radiculomedullary artery, namely the Adamkiewicz artery in this case . A postoperative CT scan showed satisfactory decompression (Figure 9) .

Postoperative Course

The postoperative course was uneventful and the patient returned to her work in 2 months . Clinical and radiological follow-up examinations 18 months after surgery showed no evidence of tumor recurrence . 0090-3019/92/55 .00



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Figure 3 . CT scans of ihoracolumbar spine demonstrati_g hypero m , sf intolving the left T12 and LI laminae and pedddes .

Figure4 . Magni tic resonance image sf thcracoiamhrte sfiieic. Upper left) T2-weighted axial image. (Lower left) TI-ueighted axial image . (Right) T2-u zighted wni1tel image . Images show mottled hyperintensity lesion surrounded by low signal intensity area both on TI- and T2-ueighted images, indicating the fatty degeneration of the tenor

Figure 1 . Thoracolumbar spinal x-ray film showing bulging of the T12 and LI vertebral columns.

Figure 2 . Bone scan and gallium scintigram shot, ing abnormal uptake at the thoracolumbar junction .

Figure 5 . Enhanced magnetic resonance image of thrnacolumbar spine . (Left) T i-ueighted axial image . (Right) T I-ueighted eagittal image . The tumor is not enhanced by gadolinium-DTPA .



Ossifying

Fibroma

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Thoracolumbar Spine

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Figure 8 . Angiogratus of thoracolumbar spine . (Left) Subtraction film . (Right) With landmark . Angiogranu show no abnormal vascular supply to the tumor .The great radicular artery of Admnkieu iez is derived front the left T12 subcostal artery.

by osteoblasts . The spicules of bone were interspersed with fibrous proliferation and were rimmed with osteoblasts or osteoclasts in some parts . Mitotic figures were rare, and no atypical cellular features were seen (Figure 10) . Discussion

Figure 6. Myclogranes of thoracolumbar spine . (Lef) Artteroprester-ior steun . Osieoplastic Its zoos on the left side of the 7'12 and LI laminae i pushing the ducal ac to the right . (Right) Lateral i ierc .

Ossifying fibroma has been considered benign from a pathological point of view and has been found to involve mainly the skull and long bones . A rare case involving the thoracolumbar spine is presented . The tumor invaded the spinal canal and compressed the cord and nerve root, resulting in radiculomyelopathv . Clinical and radiological differentiation from other bone tumors was made by means of a review of the literature . Sex and Age

Pathological Examination Histological examination revealed a fibro-osseous lesion with prominent rimming of the bone trabeculae formed

Figure 7 . CT myelogroms oft horace/ausbarspine . Bony density lesion on the left side of the T12 and LI laminae is pushing the dural sac to the right .

In a series of 20 ossifying fibromas reported by Smith and Zavaleta {81 there was a distinct preponderance of female patients and an average age of 21 . No familial

Figure 9. Postoperatii e CT scars of thoracolunrbar spine showing results of laneinectome ofT12 and LI . excision of the bony tumor, mad foramineotomy of left T12 and LI .



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Figure 10. Hirtologicalfindingishrnaingafibro-olseourleiionwithpronminent rimming of the bone trabecedae formed by orteoblast.

trait was found in their cases . Of seven cases reported by Fu and Perzin [3], five occurred in females (average age 15 years) . Ossifying fibroma distinctly affects persons in younger age ranges . It is therefore presumed that in our patient the lesion had remained asymptomatic for a certain period of time, possibly because of the slowgrowing characteristics of the tumor .

Ohyama

et

al

affected in 16 . But there were no cases in which the spine was affected [6] .

Pathogenesis These tumors usually enlarge slowly . The pathogenesis is still debatable . Neoplasia, trauma, and developmental abnormalities have been described as possible pathogenetic lesions [5,8,9] . No pathogenetic lesion was found in our case .

Localization A preponderance of the growth of ossifying fibroma occurs in the mandible, maxillary sinus, and orbital roof . It also grows in the long bones of the lower extremities, of which the tibia is affected most frequently [4] . Of 811 cases analyzed by Majewski et al [6], the maxillary sinus was affected in 352, and the mandible in 269 . Ossifying fibroma occurred in the frontal, sphenoidal, and zygomatic bones in 91 cases, and the tibia was

Radiological Features In contrast with our case, ossifying fibroma is usually a well-demarcated lesion, circumscribed by the thin shell of bone that is expanded as the tumor grows . In the cases in which the skull is affected, there may be bone destruction with opacification of the sinus . Thus a soft tissue or a calcified mass may be seen in the sinus or the orbit [3,7] .



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Ossifying Fibroma of the Thoracolumbar Spine

Pathology On gross examination, it is difficult to differentiate ossifying fibroma from fibrous dysplasia, except that the former usually appears to he more clearly demarcated from adjacent normal tissue . Microscopically, ossifying fibroma shows both fibrous and osseous tissue, with the former predominating. Mitosis is occasionally seen . Osteoid tissue is seen focally in the stroma. With further maturation, osseous tissue, ranging from osteoid lined by osteoblasts to spicules of mature bone, is found . Moderate to high cellularity is seen in the stroma . Osteoclasts and foci of cystic degeneration are occasionally demonstrated . The whole spectrum of intramembranous ossification is seen in normal bone formation . The bony structure and osteoid tissue at the various stages of maturation are scattered throughout the entirety of ossifying fibroma lesions [3] . In out cases histological examination revealed a fibro-osseous lesion with prominent rimming of the bone traheculae formed by osteoblasts . The spicules of bone were interspersed with fibrous proliferation and were rimmed with osteoblasts or osteoclasts in some parts . These findings were compatible with those described above ; therefore, our case was diagnosed as ossifying fibroma .

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series of 20 ossifying fibroma cases reported by Smith and Zavaleta [81 total resection was performed in 17 cases without recurrence . The tumor recurred in two of partially resected cases 3-4 years after surgery . From the literature the rate of recurrence in cases of partial resection can be set at 28%-75°lc [2-4, 8] . Definer [1}, who performed total resection of such tumors, found no recurrence in four patients . Complete tumor excision should therefore be the treatment of choice . However, considering the stabilization and the alignment of the vertebrae affected, and to preserve the Adamkiewicz artery, partial resection of the rumor was considered to be the best treatment in this case . Ossifying fibroma, although rare, should be included in the differential diagnosis in the case of an osteoplastic lesion of the spine .

References L Definer LP . Tumors

of the

mandible and maxilla in children . Cancer

1973 :31 :364-84 .

Eveaole LR et al . Ossifying fihroma : a cllnicopathological study of sixty-tour cases . Oral Surg Oral Med Oral Pathol 1985 ;60 :505-11 . 3 . Fu Y-S . Perzin KH . Non-epithelial tumors of the nasal cavity, paranasal sinuses, and nasopharynx : a clinicopathologic study . Cancer 19'4 ;33 :1289-1305 . i . Goerger TG et al . Long bone ossifying fihroma. Cancer 2.

1966 ;31) .206'-72,

Treatmneni and Results Ossifying fibroma involving the spine is an extremely rare lesion . In this case a pathologically benign lesion slowly expanded into the spinal canal and caused progressively increasing radiculomyelopathy . Therefore a decompressive procedure was inevitable . Villemure et al [91 recommend that a margin of normal bone including the periosteum he removed to prevent recurrence . In a

Kenhpson RL . Ossifying fibroma of the long bones . A light and electron microscopic study . Arth Parhol 1966 :82 :218-33 . 6 . Majewski VA et al . Das ossihzierende Knochenfibrom (OF) . Poaschr Geb Roemgenstr 1984 :140 .179-8 ' . Schwartz E . Ossifying fibroma of the face and skull . J Laryngol Orol 5.

190' :S l 1 :1012-15 . 8. 9.

Smith AG, Zavalcra A . Osteoma, ossifying fibroma and fibrous dysplasia oL facial and cranial hones . Arch Parhol 1952 :54 :507-27 . Villemure J-G et al . Giant ossifying fihroma of the skull . J Neurosung 198, :58 :602-6-