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Aneurysmal Bone Cyst: Rapid Deterioration in a Long-Standing Tumor

Haim Krissi, MD, Boris Kaplan, MD, josef Shalev, MD, joseph Sack. MD

Aneurysmal bone cyst, first described by Jaffe and tal, the girl had begun to experience worsening of Lichtenstein I in 1942 as a rare, localized tumor of the occurrences. the long bones and spinal vertebrae, characterized During the previous 2-year period, she had by the "blowout distention" of the skeletal con­ been examined several times by a pediatrician and tour on a radiograph.2 This neoplasm, usually orthopedist, but no history or physical finding found in children and young adults, constitutes could elucidate her pain. During these examina­ 1.4 percent of all primary bone tumors.3 The cyst tions a routine complete blood count, blood is occasionally associated with other tumors of the chemistry analysis, and urine analysis yielded nor­ bone, such as osteoblastoma, osteosarcoma, giant mal values. Tests for antinuclear antibodies and cell tumor, and fibrous dysplasia,4 and has occa­ rheumatoid factors, which can appear in juvenile sionally been reported to occur at a site of previ­ rheumatoid arthritis and systemic lupus erythe­ ous trauma to the bone.5 There is a tendency to­ matosus, were negative. No abnormalities were ward rapid growth with local expansion, which found on an abdominal radiograph and sonogram, can exert pressure on an adjacent structure. 3 except for a small stone in the left kidney with Histologically, aneurysmal bone cyst is a cystic, mild widening of the calyces. Renal colic was sus­ osteolytic vascular tumor, replete with giant cells pected. Her blood sedimentation rate was 60 mm and fibrous septa. The tumor has a solid variant in the first hour, but no satisfactory explanation with fibroblastic proliferation, giant cell areas, was provided. stromal hemorrhage, and new bone production.6 When she was first examined in the emergency When an aneurysmal bone cyst appears in the department, the girl appeared to be well devel­ spine, it is generally diagnosed within a few oped and mildly obese, with no signs of distress.

months after the onset of clinical symptoms, She complained of pain and tenderness in the http://www.jabfm.org/ which include local pain and swelling accompa­ lumbar spine region. Findings of a complete phys­ nied by reactive local muscle stiffness and restric­ ical examination were unremarkable. The lumbar tion of movement. Only in advanced and rare spine was found to be mildly tender without cases does the aneurysmal bone cyst exert pressure spasm or fullness. Muscle strength, sensation, and on the spinal cord, which can lead to neurologic deep tendon reflexes of the lower extremities were deficits. 6,7 We describe the diagnosis, manage­ normal. Rectal and genital examinations revealed on 27 September 2021 by guest. Protected copyright. ment, and follow-up of an aneurysmal bone cyst in no abnormalities. Complete blood count was nor­ a 14-year-old girl. mal. Laboratory results were normal, except for a high sedimentation rate. The pain was sponta­ Case Report neously relieved, and she was sent home. A 14-year-old girl complained of a 2-year history One week later her condition was rapidly dete­ of recurrent episodes of nonradiating low-back riorating. She complained of diurnal enuresis, and pain, which lasted for several days and was re­ on examination there was increased weakness in lieved with nonsteroidal anti-inflammatory drugs. both legs, especially in the proximal muscles, an Two weeks before she was admitted to the hospi- increase in the patellar and Achilles tendon re­ flexes, positive bilateral Babinski reflexes, and footdrop in both legs. Submitted, revised, 18 September 1998. An abdominal radiograph showed mild scolio­ From the Department of Obstetrics and Gynecology (HK,BKJS), Rabin Medical Center, Beilinson Campus, and sis in the lumbar region of the spine, but no other the Department of Pediatrics as), The Chaim Sheba Medical pathologic signs. Spinal computed tomography Center, and Sadder Faculty of Medicine, Tel Aviv University, Israel. Address reprint requests to Boris Kaplan, MD, 14 (CT) showed scoliosis to the left and a lytic lesion Montefiore Street, Kiriat Ono, 55226, Israel. in the posterior elements of the vertebrae at the

340 JABFP July-August 1999 Vol. 12 No.4 J Am Board Fam Pract: first published as 10.3122/jabfm.12.4.340 on 1 July 1999. Downloaded from

both legs. A histologic examination of the cyst showed it to be an oste­ olytic lesion replete with giant cells and fibrous septa, with a few solid areas of fibroblasts (Figure 3). At a I-year follow-up examina­ tion the girl had resumed full daily activities; was pain-free; had nor­ mal muscle strength, sensitivity, and reflexes; and had no urinary incontinence.

Discussion Primary tumors of the vertebrae are rare in infancy and childhood. An aneurysmal bone cyst is a rare, expanding benign lesion that ap­ Figure 1. Computed tomographic scan showing a lytic lesion in the pears most commonly in children posterior elements of the vertebrae at the DlO-D12 level, with expansion and young adults, but can occur 3 to the vertebral body from the left. This process with a thin periosteal later in life. border enters the spinal canal, pressing the cord forward and to the right. It has been suggested that aneur­ ysmal bone cyst is not a true neo­ level ofDIO-DI2, with expansion to the vertebral plasm, but rather a vascular malformation. It body from the left. This process, which had a thin probably begins with an arteriovenous fistula in­ periosteal border, entered the spinal canal, press­ side the bone, expands into the medullar space, ing the cord forward and to the right (Figure 1). and forms a cyst with blood-filled spaces sur­ Magnetic resonance imaging (MRl) showed a rounded by a thin shell of periost.2,5 "When the space-occupying lesion at the level ofDIO-DI2, cyst appears in the spine, the neural arch is the

extradurally pressing the spinal http://www.jabfm.org/ cord forward and to the right and destroying the pedicle and the lamina. On MRI with gadolinium injection, a nonhomogeneous mul­ tilobular process was seen (Figure 2). The tentative diagnosis was an aneurysmal bone cyst. During sur­ on 27 September 2021 by guest. Protected copyright. gical exploration of the spine at the level ofDIO-DI2, a gray-red mass 6 cm long was found invad­ ing the vertebrae through the left lamina to a depth of 2 cm from D 10 and descending into the epidural space to DI2. The tumor seemed to be epidural, attached to the dura, but easily separated from it. Cauterization and curettage of the cyst by way of a laminectomy were performed. Figure 2. Magnetic resonance imaging after injection with gadolinium The patient's postoperative fol­ shows a nonhomogeneous multilobular lesion at DIO-D12level, low-up course was uneventful, and extradurally pressing the spinal cord forward and to the right, destroying she rapidly regained strength in the pedicle and the lamina of the vertebra.

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analgesia. Moreover, the abdomi­ nal radiograph did not indicate any pathologic finding because it was of an area below the level of the le­ sion, and the left nephrolithiasis found on a sonogram was mislead­ ing as a source of the pain. In ret­ rospect, the physicians should have had a higher index of suspicion for bony lesion, and earlier thorough examinations, including CT or MRI, should have been performed. In our case, prompt curettage of the bone cyst was successful, and there was no need for bone graft­ Figure 3. Histologic sample of a cystic osteolytic lesion replete with giant ing. "When possible, this method cells, fibrous septa, and a few solid areas of fibroblasts. of treatment is preferred. Even ei- ther incomplete curettage or open most frequently involved portion of the vertebrae, biopsy can result in oblitera tion of the cyst. Radio­ although other parts of the body can occasionally therapy has also been used effectively in patients be affected. Clinically the patient usually has pain who are at high risk for surgery or who are resis­ and stiffening in the affected portion of the spine tant to surgical treatment, although the possibility with restricted motion. A palpable mass appears in of grave complications, such as myelopathy, sarco­ only 6.0 percent of cases.! The lesion can enlarge matous changes, and deformation of the verte­ rapidly within a few months and cause extensive brae, make this mode of treatment undesirable. In bone destruction. On radiographic examination, large tumors that have a high risk of bleeding and the lesion usually appears as an expanding, lytic in places where curettage would be difficult, such process, surrounded by a tl1in cortical shell.2,s The as the pelvis or spine, selective embolization of the

preferred method for evaluating an aneurysmal tumor site is possible, followed by curettage, if http://www.jabfm.org/ bone cyst, after conventional radiography, is an necessary.9 The prognosis of aneurysmal bone MRI, which will provide as much or more infor­ cyst in children is most promising, although there mation than a CT.5 In our case, findings from is a high percentage of recurrence, mainly in the both CT and MRI were suggestive of aneurysmal first year after the operation and in patients who bone cyst. undergo partial resection of the tumor. These The differential diagnosis of bony causes of children require more careful follow-up and back pain in children are other tumors of the might need additional treatmentJ on 27 September 2021 by guest. Protected copyright. bone, such as osteoblastoma, osteosarcoma, os­ teoid osteoma, giant cell tumor, and fibrous dys­ Conclusion plasia. NOlmeoplastic causes comprise spondylitis, Aneurysmal bone cyst is a rare skeletal neoplasm, osteomyelitis, Scheuermann disease (osteochon­ but it is only one of the various causes for low­ dritis of the vertebral epiphyses), juvenile rheuma­ back pain that is a common complaint in the ado­ toid arthritis, and systemic lupus erythematosus. lescent. The family physician and the pediatrician Our patient complained of low back pain for 2 should be aware of these entities, be more aggres­ years before there were neurologic manifestations. sive when establishing their diagnosis of pro­ In all probability the lesion was not diagnosed ear­ longed back pain, and include advanced imaging lier because of several pitfalls: the physicians did studies in their workup. not suspect a skeletal neoplasm; tl1ere were no ex­ ternal findings on physical examination; the girl References was at an age at which low back pain, because of 1. Fly VG, Van DellenJR. Aneurysmal bone cyst of the rapid growth, is common; and the pain was not spine. S Afr Med J 1980;258 :211-3. progressive, but intermittent and relieved by mild 2. McArthur RA, Fisher RG. Aneulysmal bone cyst in-

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volving the vertebral column. A case report. J Neu­ aneurysmal bone cyst (extra gnathic giant cell reparative rosurg 1966;24:772-6. granuloma) in the axial skeleton and long bones. A 3. McLurin RL. Extramedullary spinal tumors. In: Pe­ study of its morphologic spectrum and distinction diatric neurosurgery: surgery of the developing ner­ from allied giant cell lesions. Cancer 1992;70:2642-9. vous system. American Association of Neurological 7. MacDonald P, Letts M, Sutherland G, Unruh H. Surgeons, Section of Pediatric Neurosurgery. New Aneurysmal bone cyst of the upper thoracic spine. York: Grune & Stratton, 1982:541-9. An operative approach through a manubrial ster­ 4. Mintz MC, Dalinka MK, Schmidt R. Aneurysmal notomy. Chn Orthop 1990June:I27-32. bone cyst arising in fibrous dysplasia during preg­ 8. Goodman ML. Aneurysmal bone cyst in early child­ nancy. Radiology 1987;165:549-50. hood. Orthop Rev 1986;15:457-60. 5. Miron D, Mogilner G, HorowitzJ, Moreli D, Sip­ 9. DeRosa GP, Graziano GP, Scott J. Arterial em­ lovitz L. [Aneurysmal bone cyst of a lumbar vertebra bolization of aneurysmal bone cyst of the lumbar in a child.] Harefuah 1993;124:82-5. spine. A report of two cases. J Bone Joint Surg Am 6. Oda Y, Tsuneyoshi M, Shinohara N. "Solid" variant of 1990;71-A:777-80. http://www.jabfm.org/ on 27 September 2021 by guest. Protected copyright.

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