Skeletal Radiol (2002) 31:592–596 DOI 10.1007/s00256-002-0532-x
G. Hermann M. J. Klein D. Springfield I. F. Abdelwahab S. J. Dan
Received: 21 December 2001 Revised: 19 April 2002 Accepted: 24 April 2002 Published online: 12 July 2002 © ISS 2002
G. Hermann (✉) Department of Radiology, Box 1234, The Mount Sinai-NYU Medical Center, One Gustave L. Levy Place, New York, NY 10029-6574, USA e-mail: George
[email protected] Tel.: +1-212-241-5798 Fax: +1-212-427-8137 M.J. Klein Department of Pathology, Box 1234, The Mount Sinai-NYU Medical Center, One Gustave L. Levy Place, New York, NY 10029-6574, USA
C A S E R E P O RT
Intracortical osteosarcoma; two-year delay in diagnosis
D. Springfield Department of Orthopedics, The Mount Sinai-NYU Medical Center, One Gustave L. Levy Place, New York, NY 10029-6574, USA I.F. Abdelwahab Department of Radiology of the Methodist Hospital, Brooklyn, New York USA S.J. Dan Department of Radiology of the St. Luke’s-Roosevelt Hospital, New York, USA
11-year-old patient with intracortical osteosarcoma of the tibia in whom the tumor was present for 2 years and became painful 3 months prior to presentation. Keywords Osteosarcoma · Surface osteosarcoma · Malignant bone tumor · Radiographs · CT · MRI Abbreviations ICOS Intracortical osteosarcoma · OS Osteosarcoma
Abstract Intracortical osteosarcoma is the rarest type of osteosarcoma. In most instances the tumor arises in the cortex of the femur, less commonly, in the tibia. We describe an
Introduction
Case report
Intracortical osteosarcoma (ICOS) is the least common subtype of osteosarcoma. It comprises less than 1% of all osteosarcomas [1]. Jaffe [2] described this tumor in two patients for the first time in 1960. Twelve additional cases have been reported in the literature [3, 4, 5, 6, 7, 8, 9, 10, 11]. In all cases, the tumor arose in the cortex of the shaft of the femur or tibia. Radiologically, the lesion may simulate a benign process. A history of trauma was noted in less than half of the reported cases. We describe a case of ICOS in which the diagnosis was delayed for 2 years. The lesion at original presentation mimicked osteoid osteoma.
An 11-year-old boy with an unremarkable past medical history presented from an outside institution with a 2-year history of a mass in the anterior portion of the left tibia. During the preceding 3 months he had begun having increased pain in the mass, and it had enlarged. The pain increased with physical activity and the mass became tender. At presentation 2 years earlier the patient had stated that the mass was not significantly tender. At that time, the diagnosis suggested was osteoid osteoma; however, no further clinical follow up was done. Physical examination revealed a nodule, visible over the anterior aspect of the mid portion of the left tibia. It was very tender and hard. There were no signs of inflammation and no pulsation. The extremity was otherwise normal. Laboratory findings were within normal limits. 99m TC MDP scintigraphy showed increased uptake over the mid tibia. Radiographs of the left leg 2 years earlier (Fig. 1A) showed thickening of the anterior aspect of the tibial cortex at mid-diaphysis with radiolucency at its surface.
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Fig. 1A–C Lateral radiograph of the left tibia. A There is a thickening of the anterior aspect of the cortex of the midshaft of the tibia with a lucency at the center (arrow). B Two years later, there is no change. C CT scan of the middle onethird of the tibia. There is a thickening of the cortex with a small lucency at the surface. Note a small calcification above the lesion (arrow) A recent radiograph (Fig. 1B) revealed minimal enlargement. CT scan demonstrated thickening of the anterior cortex with a small lucency on the surface (Fig. 1C). The lucent area measured 1.4×2.9 cm in diameter. The cortical thickening included an approximately 13 cm long segment along the anterior aspect of the tibia. The medullary cavity showed normal attenuation. There was no sign of marrow infiltration. There was a small calcification in the soft tissue, above the cortex.
T1 weighted MR imaging revealed a thickened cortex with low SI that became bright on T2 WI (Fig. 2). The medullary cavity appeared to be uninvolved. A radiologic diagnosis of osteoid osteoma or Brodie’s abscess was suggested. An operative procedure was performed, during which the lesion was examined in sequentially removed shavings.
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Fig. 2A, B MRI of the left tibia. A T1 weighted axial images revealed a slightly thickened anterior cortex with a small focal area of low signal intensity (arrow). B On T2 weighted images the area becomes bright (arrow). The medullary cavity is uninvolved
Fig. 3A–C Intracortical osteosarcoma. A Low power photograph from outside (top) toward inside demonstrates multilayered matrix consisting of alternating immature bone and cellular hyaline cartilage. (×40) B Medium power through one portion of the lesion demonstrates microtrabecular bone formation in a fibrovascular stroma, which, by itself is reminiscent of osteoid osteoma (×150). C High power demonstrates cellular, immature bone matrix. The intraosseous spaces are permeated by fibrous tissue (bottom) and cellular, atypical hyaline cartilage (top, right) (×350)
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Pathology Sections of the lesions were somewhat difficult to interpret due to artifacts induced by piecemeal removal, surgical fragmentation induced by shaving the lesion in stages, and because the lesional tissue was intimately admixed with periosteal new bone. When all four serial shavings were compared with the radiographic findings, it was evident that the lesion was a neoplasm. Some portions of the shavings demonstrated the production of microtrabecular osteoid and bone with a cellular fibrous stroma reminiscent of osteoid osteoma (Fig. 3A). Other portions of the tumor demonstrated the production of hypercellular hyaline cartilage. The cellular hyaline cartilage and immature bone formation in the present lesion were disposed in irregular, wavelike layers somewhat reminiscent of fracture repair, but without the organization or zonation of fracture callus (Fig. 3B). There was no evidence in any of the clinical imaging studies to suggest a history of fracture, and the imaging studies went back for 2 years. Some of the hypercellular cartilage was not only in continuity with immature bone formation, but it actually percolated through some of its intertrabecular spaces. In addition to its hypercellularity, the chondrocyte nuclei were enlarged and demonstrated internal nuclear detail (Fig. 3C). This combination of histological findings, particularly in the absence of evidence of fracture was considered diagnostic of low-grade intracortical osteosarcoma. A short segment of remaining cortex in continuity with this lesion was resected following the diagnosis and there was no residual tumor identified. The ipsilateral fibula was used as a bone graft. Eighteen months later the patient was well and had resumed normal activity.
Discussion Osteosarcoma (OS) arising on or near the surface of bone is an uncommon, well-recognized subgroup of OS. Of the four different types of tumor that belong to this category, intracortical osteosarcoma is the least common subtype with an incidence of 1% of all osteosarcomas [1]. Intracortical osteosarcoma is characterized as a sclerotic variant of osteosarcoma that may contain foci of cartilaginous or fibrous differentiation [3, 12]. Since the first description of intracortical OS in two patients by Jaffe in 1960, 12 additional cases have been published [2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14]. The patients’ age ranged between 10 and 43 years. Half of them were in their second decade. In all cases, the lesion arose from the diaphysis of the femur or tibia. The tumor occurred more often in male than female patients by a ratio of 2.25:1. Clinically, the patients presented with moderate pain and local tenderness. A history of minor trauma was mentioned in about 40% of the reported cases [11]. Less than one half of the patients developed a lump. The duration of the symptoms ranged from one month to one to 2 years. In our case, the mass was present for a period of over 2 years. Having recently increased in size, becoming hard and exquisitely tender. Radiologically, the lesion appeared as a localized intracortical lucency surrounded by a thickened cortex (Figs. 1, 2). At the time of
onset of the initial symptoms, the lesion was confined to the cortex resembling an osteoid osteoma. Biopsy was recommended but the patient did not return for followup. 2 years later radiographs suggested a small erosion on the anterior aspect of the cortex. CT scan demonstrated a tiny calcification in the overlying soft tissue. The medullary cavity remained uninvolved. MR imaging showed minimal thickening at the anterior aspect of the cortex with low signal intensity on T1 WI and high signal intensity on T2 WI. There was no evidence of marrow infiltration. In two previously reported cases, the authors noticed peritumoral and medullary edema. Histologically, medullary micro-invasion was observed in these two instances [2, 3]. Griffith et al [11] speculated that the predilection for intracortical osteosarcoma in the thickened cortex of the midshaft of the long bones rather than in the thin cortex of the metaphysis where conventional osteosarcoma arise, may explain the rare incidence of medullary infiltration. The delay in diagnosis in our case was related to the fact that the clinical symptoms were mild. Anderson et al [7] reviewed six reported cases and concluded that in all cases the patients presented with mild pain. The preoperative diagnoses were non-ossifying fibroma, fibrous dysplasia, osteoid osteoma, osteoblastoma, and Brodie’s abscess. The delay in diagnosis seems to be related to the mild clinical symptoms and benign-appearing imaging studies. The majority of patients reported in the English literature are alive and well. Consequently the delayed diagnosis did not have an adverse effect on the prognosis. Increased serum alkaline phosphatase levels and moderate to severe pain usually accompany osteoblastoma, osteoid osteoma and intracortical abscess. Biopsy, however, is the only definitive diagnostic tool. While the presence of hyaline cartilage in this otherwise osteoblastic lesion strongly suggested the possibility of osteosarcoma, on rare occasions, hyaline cartilage has been described in both osteoid osteoma and osteoblastoma [14]. In the cases described, the cartilage differentiation has been confined to a localized central area rather than in the diffuse distribution seen in the present case. Intracortical osteosarcoma is histologically characterized by minimal anaplasia. Mirra et al [3] and more recently Griffith et al [11] reviewed the pertinent literature and found that 5 patients were disease-free 3–19 years after surgery. One of the reported cases survived 30 years [15]. Another patient died 26 years later, following several recurrences.
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References 1. Schajowicz F, McGuire MH, Aroujo SE, Muscolo DL, Gitelis S. Osteosarcomas arising on the surfaces of long bone. J Bone Joint Surg [AM] 1988; 70:555 2. Jaffe HL. Intracortical osteogenic sarcoma. Bull Hosp Joint Dis 1960; 21: 189–197 3. Mirra JM, Dodd L, Johnston W, Frost DB, Barton D. Case report 700. Primary intracortical osteosarcoma of femur, sclerosing variant grade 1 to 2 anaplasia. Skeletal Radiol 1991; 20:613–616 4. Kyriakos M. Intracortical osteosarcoma. Cancer 1980; 46: 2525–2533 5. Picci P, Gherlinzoni F, Guerra A. Intracortical osteosarcoma: rare entity or early manifestation of classical osteosarcoma? Skeletal Radiol 1983; 9:255–259
6. Vigorita VJ, Jones JK, Ghelman B, Marcove RC. Intracortical osteosarcoma. Am J Surg Pathol 1984; 8:65–71 7. Anderson RB, McAlister JA, Wrenn RN. Case report 585. Intracortical osteosarcoma of tibia. Skeletal Radiol 1989; 18:627–630 8. Lopez-Barea F, Rodriquez-Peralto JL, Gondalez-Lopez J, Sanchez-Herrera S, Sanchez-del-Charco M. Intracortical osteosarcoma. Clin Orthop 1991; 268: 218–222 9. Kyriakos M, Gilula LA, Becich MJ, Schoenecker PL. Intracortical small cell osteosarcoma. Clin Orthop 1992; 279:269–280 10. Blasius S, Link TM, Hillman A, Rodl R, Edel G, Winkelmann W. Intracortical low grade osteosarcoma. A unique case and review of the literature on intracortical osteosarcoma. Gen Diagn Pathol 1996; 141:273–278
11. Griffith JF, Kumta SM, Chow LTC, Leung PC, Metreweli C Intracortical osteosarcoma. Skeletal Radiol 1998; 27:228–232 12. Murphy MD, Robbin MR, McRae GA, Flemming DJ, Temple TH, Kransford MJ. The many faces of osteosarcoma. RadioGraphics 1997; 17:1205–1231 13. Lichtenstein L. Bone tumors, 5th ed. St. Louis: Mosby 1977; 220–252 14. Dorfman HD, Czerniak B. Bone tumors. St. Louis: Mosby 1998 15. Scranton PE Jr, De Cicco FA, Totten RS, Yunis EJ. Prognostic factors in osteosarcoma. A review of 20 years experience at the University of Pittsburgh Health Center Hospitals. Cancer 1975; 36:2179–2191
