Giant notochordal hamartoma of intraosseous origin: a newly reported benign entity to be distinguished from chordoma. Report of two cases

Two cases are reported of a newly described intraosseous entity of vertebral bodies deemed "giant notochordal hamartoma of intraosseous origin". This entity is commonly mistaken for chordoma and must be distinguished from it as the consequences of misinterpretation may be serious. The clinical, radiological and histologic criteria that can be used to distinguish these two entities are emphasized. Included is a proposed pathogenesis for this lesion, its probable notochordal origin, and a review of other probable cases.

Intraosseous glomus tumor of the fibula

Glomus tumor is a rare, benign vascular tumor and intraosseous glomus tumor, which arises primarily within bone, is even rarer. Fewer than 20 cases have been reported in the literature. We present the case of a 34-year-old woman with glomus tumor primarily in the midshaft of the fibula that radiologically mimicked chondromyxoid fibroma, aneurysmal bone cyst or adamantinoma, together with a review of other reported cases.

Pseudoanaplastic giant cell tumor of bone

Marked nuclear atypia can be found in a variety of benign mesenchymal tumors, including ancient schwannomas, symplastic leiomyomas, osteoblastomas, and chondromyxoid fibromas. Such nuclear atypia is believed to represent a degenerative phenomenon and does not indicate aggressive behavior. Separation of these pleomorphic but benign lesions from true sarcomas may be difficult. We are aware of only one prior description of such degenerative atypia in benign giant cell tumor of bone. We report a benign giant cell tumor of bone arising in the sacrum of a 21-year-old white female. Preoperative embolization of this lesion had been performed, and subsequent curetting revealed marked atypia suggestive of an anaplastic malignancy. However, only very rare mitotic figures were present, and the radiographs were consistent with a benign giant cell tumor. A diagnosis of benign giant cell tumor was made, and no recurrence or metastases have been observed during the 4-year postoperative period.

Benign and malignant cartilage tumors of bone and joint: their anatomic and theoretical basis with an emphasis on radiology, pathology and clinical biology. II. Juxtacortical cartilage tumors

In part I, we reviewed the varied clinical presentations, pathogenesis, histologic findings, radiologic findings, and treatment of intramedullary cartilaginous lesions of bone. In this section, we will evaluate our cases and consultations of juxtacortical cartilaginous tumors. Radiographic differential diagnosis includes the numerous juxtacortical lesions particularly osteochondroma, parosteal chondroma, Trevor's disease, trauma (fracture and periostitis ossificans), and the low- and high-grade surface osteosarcomas. By emphasizing pathogenesis in conjunction with radiographic and histologic findings, pitfalls in diagnosis and subsequent treatment can be avoided in such cases.

Pseudoanaplastic chondromyxoid fibroma

A 19-year-old man presented with a chondromyxoid fibroma of the distal phalanx of the great toe that was originally diagnosed as osteosarcoma rather than "dedifferentiated" chondrosarcoma. Radiographs showed a large, expansive, and calcified tumor of the distal phalanx. Although the tumor had the architectural and matrix patterns of a chondromyxoid fibroma, high-power examination demonstrated that the lesion had such severe nuclear pleomorphism that it was mistaken for high-grade sarcoma. The purpose of this report is to present the criteria used to differentiate a benign pseudoanaplastic chondromyxoid fibroma from chondrogenic high-grade sarcomas.

Osteochondromalike parosteal osteosarcoma: a report of six cases of a new entity

OBJECTIVE

Our purpose was to describe a rare juxtacortical bone sarcoma with deceptively benign, osteochondromalike histologic characteristics. We present criteria by which this low-grade malignant neoplasm can be distinguished from other benign and malignant surface lesions of bone with particular emphasis on the imaging features.

MATERIALS AND METHODS

Six cases of a low-grade, chondroossifying parosteal sarcoma of bone were reviewed. Patients included four males and two females 11 months to 66 years old. Histologic findings from initial tumors and from recurrent tumors were reviewed. Two musculoskeletal radiologists analyzed the imaging studies, which included plain films, CT scans, MR images, and a bone scan.

RESULTS

Histologically, the lesions were characterized by a thin layer of proliferating, periosteally derived spindle cells overlying a thin, low-grade malignant cartilage cap that underwent calcification, neovascularization, and conversion into benign bone and marrow fat. These lesions were unique in that the malignant elements were only at their periphery. All six cases were initially misdiagnosed as benign lesions on pathologic evaluation. In each patient, imaging revealed a "pasted-on" ossified surface lesion with an intact underlying cortex and no medullary involvement. In three cases, recurrent tumors had histologic appearances consistent with conventional parosteal osteosarcoma. Dedifferentiation, metastases, and death occurred in one of these three cases.

CONCLUSION

To our knowledge, this surface lesion of bone has not been specifically described. Whether this tumor constitutes a distinct entity or is a specialized variant of parosteal osteosarcoma is unclear. Precise radiologic-pathologic correlation is essential for appropriate diagnosis and management.

Benign and malignant cartilage tumors of bone and joint: their anatomic and theoretical basis with an emphasis on radiology, pathology and clinical biology. I. The intramedullary cartilage tumors

We reviewed 845 cases of benign and 356 cases of malignant cartilaginous tumors from a total of 3067 primary bone tumors in our database. Benign cartilaginous lesions are unique because the epiphyseal plate has been implicated in the etiology of osteochondroma, enchondroma (single or multiple), periosteal chondromas and chondroblastoma. In the first part of this paper, we will review important clinical, radiologic and histologic features of intramedullary cartilaginous lesions in an attempt to support theories related to anatomic considerations and pathogenesis.

Benign giant cell tumor of bone with osteosarcomatous transformation ("dedifferentiated" primary malignant GCT): report of two cases

It is not uncommon for sarcomatous transformation of giant cell tumor (GCT) of bone to occur after radiation, but rarely does malignant transformation occur spontaneously, with less than 15 cases reported up to 1995. Only four of these cases have been documented in detail. We report two additional cases of GCT of bone spontaneously transforming or "dedifferentiating" into osteosarcoma without radiation therapy. The first case is absolutely unique and most interesting in that the dedifferentiation process occurred in one of multiple GCT lung metastases 6 years after successful eradication of a primary tibial tumor. The right lung was resected due to development of a large tumor, and at pathologic examination, demonstrated several small nodules of conventional GCT and a much larger, 14-cm mass composed of a mixture of GCT and high-grade osteosarcoma. The second case involved a physician, who had a large tumor in the sacrum with vague symptoms for 8 years. Open biopsy revealed conventional, benign GCT of bone with a secondary aneurysmal bone cyst. Complete curettage 2 weeks later revealed, in addition to areas of conventional, benign GCT a second component of very high grade osteosarcoma. Both patients died less than 1.5 years from diagnosis. This report of osteosarcomatous transformation of a conventional GCT of bone strengthens the theory that there is a mesenchymal cell line in GCT that may spontaneously transform to sarcoma.

Intraoperative pathologic consultation (IOC) for tumors of the bone

When combining clinical examination, laboratory information and noninvasive imaging studies the differential diagnosis of bone lesions is narrowed. For those who are not experts in the field the major purpose of the IOC is to insure that adequate tissue has been obtained and to triage the tissue in the process preparing imprints, whenever possible; fixing some tissue for possible electron microscopic review; placing some tissue in B5 fixative for better cytologic detail; and to save some undecalcified tumor tissue in formalin in case immunostaining procedures are required. Most community pathologists should not be attempt to make an absolute diagnosis at the time of IOC, in many cases. The surgeon should always be warned that despite seeming benignancy 50% of primary bone tumors are malignant, that benign lesions can prove to be low grade sarcomas after full review, and vice versa that occasional cellular, "pleomorphic" lesions can be benign (aneurysmal bone cyst, early reparative and pseudosarcomatous lesions). Following review of the permanent sections, and other appropriate procedures an accurate diagnose is possible in the majority of cases. If the diagnosis is particularly difficult or questionable the above materials can be sent to a bone tumor specialist.

Clear-cell chondrosarcoma with elevated alkaline phosphatase, mistaken for osteosarcoma on biopsy

This paper report a case of a pelvic clear-cell chondrosarcoma that was initially diagnosed as clear-cell osteosarcoma after needle biopsy. Preoperatively, laboratory studies revealed an elevated alkaline phosphatase and needle biopsy showed clear cells producing osteoid. Internal hemipelvectomy was performed and final pathology was most consistent with clear-cell chondrosarcoma, despite a negative S-100 immunohistochemical stain. Distinguishing between these two entities is clinically important because treatment differs. In this case, the patient did not receive pre-or postoperative chemotherapy and is disease free more than 2 years later.

Ribbing disease (multiple diaphyseal sclerosis): imaging and differential diagnosis

OBJECTIVE

This study describes the clinical presentation and the course of Ribbing disease in six patients and illustrates imaging features on plain radiography, conventional and computed tomography, and 99mTc-methylene diphosphonate bone scans.

MATERIALS AND METHODS

Between 1982 and 1990, six female patients presented with painful bony lesions that were believed to be Ribbing disease. Ten bones were affected: both tibiae in three patients, a unilateral tibia in one, both femora in one, and a unilateral femur in one. Plain radiographs and either conventional or computed tomography were available for all patients and 99mTc-methylene diphosphonate bone scans, for five patients. All patients underwent open biopsy and/or surgical decompression.

RESULTS

The diagnosis was reached in all patients through a combination of clinical findings (lack of systemic signs of infection or laboratory values suggesting metabolic bone disease), imaging, histologic evaluation, and specimen cultures. Radiographs and tomographic studies showed benign-appearing endosteal and periosteal cortical thickening. Intense uptake of radionuclide tracer was confined to the shaft of all involved bones. All pathologic specimens revealed nonspecific changes that included a slow increase in the mass of cortical and endosteal bone. These specimens also assisted in excluding neoplastic or infectious causes for the new bone formation.

CONCLUSION

Ribbing disease is a rare disorder that, on imaging studies, may simulate stress fracture, chronic infection, bone-forming neoplasia, or a systemic metabolic or endocrine disorder. Clinical and imaging features may suggest the correct diagnosis.

Tissue reaction to metal on metal total hip prostheses

The periprosthetic tissue reaction to polyethylene wear debris in metal on polyethylene total hip replacements is strongly implicated as the cause of osteolysis. This has led to a renewed interest in metal on metal total hip replacements. However, little is known about the role of wear debris in failures of these prostheses. Capsular and interface tissues from 9 long and short term metal on metal total hip replacement retrievals were studied to assess the tissue reaction around these prostheses. As compared with metal on polyethylene cases, the extent of the granulomatous inflammatory reaction and the presence of foreign body type giant cells was much less intense in metal on metal cases, likely because of the lower numbers and overall smaller size of metal wear debris particles. This may lead to a better transport of the particles from the joint tissues and a lower incidence of periprosthetic osteolysis around metal on metal hip replacement.

Osteosarcoma and Ewing's sarcoma in a retinoblastoma patient

Retinoblastoma, though uncommon, frequently is associated with other second malignant neoplasms, especially bone sarcomas. These second neoplasms can occur in sporadic cases of retinoblastoma, though they more commonly are associated with genetic forms of the disease. This is the first known report of 2 histologically distinct bone sarcomas in a patient with retinoblastoma.

Multifocal pigmented villonodular synovitis in a child. A case report

Pigmented villonodular synovitis is a well-described disease that almost universally involves a single site. This is a report of an unusual case of multiple site involvement of pigmented villonodular synovitis in a child. In addition to multiple site involvement, the case is unusual for several reasons: asymmetric involvement, involvement of both upper and lower extremities, involvement of the pes anserine tendons, and the patient is an otherwise healthy child.

Giant bone island of femur. Case report, literature review, and its distinction from low grade osteosarcoma

A 42-year old male with the largest reported giant bone island (10.5 cm in length) is presented. Due to its ominous size, association with some degree of pain and increased uptake on radionuclide bone scan, a biopsy was considered necessary definitively to rule out a slow-growing osteosarcoma or blastic metastasis. Documentation of growth in adult patients of conventional and giant bone islands, coupled with evidence of increased radionuclide uptake, makes the clinicoradiological distinction between bone islands and blastic malignancies difficult. Guidelines for biopsy versus serial radiographic follow-up of such lesions are addressed.

Primary malignant mesenchymoma of bone: case report, literature review, and distinction of this entity from mesenchymal and dedifferentiated chondrosarcoma

The seventh case of primary malignant mesenchymoma of bone is reported. It is compared to the other six cases in the literature and clinicopathologic pattern of this entity is developed. Primary malignant mesenchymoma of bone is compared to mesenchymal chondrosarcoma and dedifferentiated chondrosarcoma. Differences as well as similarities are discussed and a more current classification scheme for malignant mesenchymoma of bone is proposed.

Paget's disease of bone: review with emphasis on radiologic features, Part II

Part I discusses the correlation between the clinical, radiology and histologic features with the three phases (incipient, mid- and late phase) of Paget's disease. In this section, we will discuss in detail the radiologic features by location as well as aberrant radiographic presentations in addition to secondary tumors such as post radiation sarcomas and giant cells tumors which occur in Paget bone. Because Paget's disease generally affects people in their middle and late ages, the differential diagnosis often includes metastatic disease and the differentiation can often be quite challenging. Moreover, metastatic disease to bones afflicted with Paget's disease can further add diagnostic confusion. These critical aspects will be discussed in this section of Paget's disease of bone.

Paget's disease of bone: review with emphasis on radiologic features, Part I

Distinctive clinical, radiologic and pathologic features are seen in Paget's disease of bone. These distinct features can be divided into three phases; initial phase, midphase, and late phase. The clinical features may vary from patients being asymptomatic (involving a single bone) to patients having severe, multiple bone involvement with systemic disease. Radiologically, there are unique features which can differentiate Paget's disease from other bone diseases. The radiologic features follows the histologic findings on light microscopy. The correlation of the different phases with the clinical, radiologic and pathologic features of Paget's disease allows for early accurate diagnosis and treatment.

Chondroblastoma arising from a nonepiphyseal site

Chondroblastoma is a rare, benign primary bone tumor usually involving secondary centers of enchondral ossification. The consistent epiphyseal location in the great majority of chondroblastomas signifies that the tumor may arise from an aberrant germ cell of the physeal plate. This case report describes a chondroblastoma located in a atypical nonphyseal location, namely in the right fourth metatarsal base. Cases such as these imply that the cell of origin may not exclusively be derived form the physeal plate. The clinical-radiographic significance is that historically chondroblastoma is considered an epiphyseal lesion, but rare cases such as the one reported here and those of the skull demonstrate that this is not always a characteristic of these tumors. The implication from a histogenetic standpoint is that chondroblastoma may, on rare occasions, occur in an area of an enchondrally formed bone other than adjacent to the physeal plate. We are presently investigating the histogenetic relationship of the chondroblastoma (CB) of bone to CB of soft tissue, giant-cell tumor of tendon sheath (GCT-TS), pigmented villonodular synovitis (PVNS) and chondroma of tendon sheath (chondroma of soft parts). We now have collected about 15 cases of GCT-TS and PVNS with extensive areas of chondroid and/or cartilage differentiation that cannot be distinguished from CB of bone by histologic or electron microscopic features alone. From these interesting observations we are developing the histogenetic concept that all of these lesions are interrelated to multipotential mesenchymal and/or synovial cells of the tendon sheath.(ABSTRACT TRUNCATED AT 250 WORDS)

Case report 847. Juxtacortical aggressive fibromatosis (desmoplastic fibroma) of the forearm

A case has been presented of a 14-year-old male patient who developed a fusiform mass on the volar aspect of his left forearm following two fractures. Microscopic features and plain radiography, CT, and MRI appearance of juxtacortical aggressive fibromatosis are discussed.

Pulmonary metastases of stage IIB extremity osteosarcoma and subsequent pulmonary metastases

PURPOSE

This study investigated prognostic factors in nonmetastatic high-grade extremity osteosarcoma and the prognosis following resection of subsequent pulmonary metastases, with emphasis on the effect of chemotherapy-induced tumor necrosis.

PATIENTS AND METHODS

We reviewed 111 consecutive patients with high-grade nonmetastatic extremity osteosarcoma treated with preoperative chemotherapy and surgical resection, with additional review of 36 patients who had subsequent pulmonary metastases resected.

RESULTS

The overall 5-year survival rate was 53%. In resected primary tumors, tumor-free resection margin (P < .001) and increasing chemotherapy-induced tumor necrosis (> 90% threshold, P < .003) correlated with increased metastasis-free survival. Relative risk factors for metastases were as follows: tumor-containing resection margin (most likely to metastasize); poor response to preoperative chemotherapy and/or lack of postoperative chemotherapy (next worse prognosis); and excellent response to preoperative chemotherapy (> or = 90% necrosis) combined with postoperative chemotherapy (best prognosis). The 5-year survival rate following pulmonary metastasis resection was 23%, whereas a 0% 4-year survival rate followed development of bony metastases (P < .001). The extent of tumor necrosis in resected pulmonary metastases did not affect prognosis. Survival was best in patients with three or fewer pulmonary nodules (P < .048), four or fewer recurrent pulmonary nodules (P < .047), unilateral pulmonary metastases (P < .037), or longer intervals between primary tumor resection and metastases (P < .082).

CONCLUSION

Intensive preoperative and postoperative chemotherapy combined with complete resection of both primary and metastatic pulmonary osteosarcomas is justified, with a goal of 100% tumor necrosis and excision. Although current treatment regimens allow effective salvage therapy for a few patients with pulmonary metastases, more effective systemic treatment is needed.

Pulmonary metastasis of benign giant cell tumor of bone. Six histologically confirmed cases, including one of spontaneous regression

Benign giant cell tumor of bone, despite being classified as benign, has the unusual ability to metastasize. Metastasis of such a tumor has been thought to be rare, with only approximately 50 such cases having been reported. However, as awareness of the metastatic potential of these tumors has increased, and methods of detection have improved, metastasis of benign giant cell tumor has been increasingly recognized. Six patients with pulmonary metastasis of giant cell tumor have been treated at a Los Angeles hospital since 1980. This represents 9.1% of all patients treated for benign giant cell tumor of bone over the same period at this institution, a higher rate than that encountered in previously published series. The early detection and treatment of this tumor is important, because those with complete resection of tumor have the best prognosis. The nature of these pulmonary metastases remains unpredictable, however, as evidenced by two of the cases in this series: one of spontaneous regression, and another of death caused by pulmonary failure.

Case report 827: Miliary osteosarcomatosis

We presented the case of a 26-year-old woman with a blastic, miliary form of osteosarcomatosis involving the axial skeleton, skull, and long bones to the elbow and knee joint regions who subsequently developed hypocalcemic tetany. Radiologically the lesions mimicked the spread of breast carcinoma, and because of the distribution of the lesions we surmised that the spread was by means of Batson's vertebral plexus of veins. The literature on multiple osteosarcomas was reviewed and an updated clinical subclassification of patients with multiple skeletal osteosarcomas presented.

Case report 823: Fibro-osseous pseudotumor of the scapula

A unique lesion discovered in the scapula of a 36-year-old woman is presented. The lesion has microscopic features resembling those of fibrous dysplasia and osteoid osteoma which we believe is identical to an entity previously only documented in the rib (fibro-osseous lesion of rib). We are of the opinion that the lesion probably represents a reactive response to trauma rather than a neoplasm and suggest the name of "fibro-osseous reparative pseudotumor" for this entity.

Case report 797: "Dedifferentiated" lipoma-like liposarcoma of soft tissue with focal transformation to high-grade "sclerosing" osteosarcoma

We have presented the first case of a lipoma-like liposarcoma of the soft tissues with high-grade malignant transformation to a high-grade osteosarcoma, the latter component of which responded well to systemic chemotherapy. With 4 months of follow-up the patient is without evidence of disseminated disease. The various types of liposarcoma are listed and several described in some detail. Of particular importance is the potential for development of a highly malignant sarcoma from a relatively indolent low-grade liposarcoma, with even osteosarcoma developing.

Serial thallium-201 scintigraphy in osteosarcoma. Correlation with tumor necrosis after preoperative chemotherapy

In 27 patients with extremity lesions (24 osteosarcoma, three malignant fibrous histiocytoma), a notable decrease in thallium-201 uptake was correlated with a good response to preoperative chemotherapy of the primary tumor. A good response is indicated by a greater than 95% tumor necrosis. Serial quantitative thallium-201 uptake of malignant bone tumors in patients receiving preoperative chemotherapy therefore can accurately predict a good histologic response and prognosis. Serial thallium scintigraphy can furthermore identify poor responses within two weeks after the initiation of treatment, or can prompt an early change in preoperative chemotherapy and facilitate limb salvage surgery.

Extraskeletal telangiectatic osteosarcoma

The first three well-documented cases of pure, extraskeletal telangiectatic osteosarcoma of the soft tissues are presented in this article. The distinctive gross features were a predominance of large, blood-filled spaces, which, on histologic examination, were large blood-filled cavities in association with cyst-like walls containing anaplastic spindle cells and definite osteoid production in two of three cases. One of the cases is of additional clinical interest because the teen-aged daughter of the woman patient had died 1 year previously of a high-grade intramedullary osteosarcoma of bone.

Case report 771: Melorheostosis in association with desmoid tumor

Melorheostosis is a rare congenital disease, some 300 cases have been reported in the literature. The main purpose of this case report is twofold: (1) to present an unusual case of melorheostosis of the right hand, beginning in infancy, with serial radiographic studies to show the gradual progression of the disease; and (2) to present the first case with the development of "aggressive" fibromatosis (desmoid tumor) of the adjacent soft tissues, associated with melorheostosis.

Case report 748: Chondroblastoma of the femur with an aneurysmal bone cyst

A case of chondroblastoma associated with an aneurysmal bone cyst has been described. The radiographic appearance of the lesion understandably reflects the combined features of both tumors. Up to one-half of all cases of aneurysmal bone cysts are found in association with other tumors, benign or malignant, and up to 15% of chondroblastomas are combined with an aneurysmal bone cyst (4).

The fibroma-like variant of epithelioid sarcoma

Five cases of a previously undescribed variant of epithelioid sarcoma are presented. This variant differs from the usual lesion in its absence of the typical necrobiotic nodular epithelioid pattern. It is instead composed of deceptively bland fibrohistiocytic and myoid cells arranged in a fibroma-like or dermatofibroma-like pattern with an affinity for osseous involvement. The clinical presentation, ultrastructural features, and presence of vimentin and low molecular weight keratin within the tumor cells justifies their designation as an epithelioid sarcoma variant.

Case report 715. Necrotic giant cell tumor of the femur

We present a giant cell tumor of the distal end of the femur that exhibited unusual diaphyseal extension and atypical MRI features. MRI demonstrated differing zonal signal characteristics in the distal metaphyseal/epiphyseal versus the diaphyseal components of the tumor. It also depicted an irregular, proximal tumor margin with an unusual, enhancing, peripheral zone. The atypical MRI features may be related to the unusual finding at pathological examination of an almost entirely necrotic giant cell tumor. This massive necrosis may illustrate a stage in the evolution of some giant cell tumors to fibrous histiocytoma-like variants of giant cell tumor or to conventional, benign fibrous histiocytoma of bone.

Case report 676: Malignant granular cell tumor (schwannoma, myoblastoma), disseminated

A rare case of metastatic, lethal, malignant granular cell tumor is presented in a 77-year-old woman. Metastases involved numerous sites, including the skeleton. The key clinical and pathological findings and differential diagnosis in benign and malignant granular cell tumor were discussed, including a review from the English literature of 23 cases of malignant granular cell tumor. The differential diagnosis was considered in detail.

Endoprosthetic replacement for stage IIB osteosarcoma

Over an eight-year period, 100 patients with IIB osteosarcoma have been managed. Eighty-one were treated with limb-salvage procedures, 78 of which involved reconstruction utilizing endoprostheses. Only 19 patients received amputation as the primary treatment for local control. Since 1984, all patients received preoperative and post-operative adjuvant chemotherapy. Those patients who received chemotherapy had a statistically significant improvement in five-year survival over those who did not (57% and 32%, respectively, p = 0.014). The functional results were good overall, with excellent results seen in distal femoral reconstruction. Twenty-eight of the 78 patients treated with endoprosthetic reconstruction experienced 30 complications (36%). Mechanical failure was the most common complication (10%) but was generally correctable. The local recurrence rate was 5% and the infection rate was 3%. Local complications were manageable. A statistical analysis revealed that the relative risk of patient death was 2.5 times higher than prosthesis failure for the 78 patients with endoprosthetic reconstruction. The intermediate-term results, with a median follow-up period of 43 months, remains encouraging.

Case report 658: Chondrosarcoma of the proximal phalanx of right fourth finger secondary to multiple hereditary exostoses (MHE)

A case of grade 1 chondrosarcoma of the phalanx of a finger complicating MHE is presented. Although the cytological features did not include anaplasia, other histological features, the presence of MHE, and recurrence of the tumor after local excision aided in making the correct diagnosis. This case emphasizes the importance of correlating the histological features with the radiological and clinical findings of all bone tumors, and especially cartilaginous lesions.

Case report 700: Primary intracortical osteosarcoma of femur, sclerosing variant, grade 1 to 2 anaplasia

We report a case of intracortical OS of the mid-femur in a 43-year-old man. The patient is the oldest reported to date. Histologically, the tumor was a sclerosing variant of OS with extensive "normalization" of nuclei. This is the most common histological subtype of intracortical OS. The patient was treated by en bloc resection without preoperative or systemic chemotherapy and is without evidence of disease with 15 months' follow-up.

Widespread inflammatory response to osteoblastoma: the flare phenomenon

A case of vertebral osteoblastoma caused a diffuse, reactive inflammatory infiltrate in two vertebrae, adjacent ribs, and the paraspinous soft tissues. The authors call this the flare phenomenon. On magnetic resonance images the diffuse inflammatory response caused a misleading appearance that simulated a malignant process (lymphoma or Ewing sarcoma). A computed tomographic myelogram was diagnostic.

Enchondroma protuberans. Report of a case and its distinction from chondrosarcoma and osteochondroma adjacent to an enchondroma

Enchondroma protuberans has been defined as an exophytic enchondroma of a long bone. We contrast a case of enchondroma protuberans with two cases of coincident enchondroma and osteochondroma. Our cases and the previously published ones lead us to believe that enchondroma protuberans is probably an enchondroma variant and that its unusual growth pattern may be related to the oblique orientation of the proximal humeral epiphysis. Unlike osteochondroma, which may be treated surgically by removing the cartilage cap and, in some cases, the stalk, enchondroma protuberans requires intralesional curettage. Enchondroma protuberans must be distinguished radiographically from chondrosarcoma.

Limb salvage therapy for soft tissue sarcomas of the foot

From 1974 to 1988, 20 patients with soft tissue sarcomas of the foot underwent attempted limb preservation at UCLA. Eighteen patients had localized tumor and two had metastases. Sixteen patients had previously untreated tumors and four patients had experienced 2-4 local recurrences before definitive management. Eleven patients had grade 3 sarcomas and nine had grade 2 sarcomas. Fourteen patients had an excisional biopsy and six had an incisional biopsy. At the time of definitive local treatment, nine patients had palpable tumor ranging from 2-10 cm (median 5 cm). Sixteen patients received sequential preoperative chemotherapy and irradiation followed by attempted conservative resection. Four patients underwent immediate conservative resection followed by postoperative irradiation. Preoperative chemotherapy was administered over 3 days intraarterially, intravenously or by a combination of routes. Fifteen patients received 60-90 mg doxorubicin and one received 120 mg doxorubicin plus 220 mg cisplatinum. Preoperative irradiation was delivered in 350 cGy fractions to total doses of 3500 cGy (one patient), 2800 cGy (8) or 1750 cGy (7). Postoperative irradiation doses were 4140-6480 delivered in 180-200 cGy fractions. Fifteen of 16 preoperatively treated patients had limb salvage surgery. Four of these 15 had positive histopathologic margins and none received postoperative irradiation. One patient required a primary amputation due to gross involvement of the os calcis. Three of four patients undergoing immediate conservative excision had positive margins and one had gross residual disease. Five patients received chemotherapy following local treatment: 3 adjuvantly and 2 for metastatic disease. Follow-up for salvage patients ranged from 6 to 99 months (median 36). Local control was achieved in 17 of 19 (90%). Two patients recurred in-field at 24 and 30 months. Fourteen of 15 preoperatively treated and salvaged patients maintained local control. Three of four managed with excision and postoperative irradiation were controlled. The actuarial local control at 3 years was 83%. One patient recurred in the inguinal lymph nodes and three patients died of metastatic disease. The actuarial survival and relapse-free survival at 3 years were 83% and 63%. Eleven patients developed acute complications and four had late complications. Of 14 patients surviving with local control, function was good or excellent in 86%. No patient has required an amputation for complications or a dysfunctional foot. Limb salvage therapy for a selected patient with a soft tissue sarcoma of the foot can reasonably be expected to result in a high probability of local control and useful function without compromising survival.

Desmoplastic fibroma of bone: radiographic analysis

Desmoplastic fibroma (DF) of bone is a rare, nonmetastasizing but locally aggressive tumor that has been discussed infrequently in the radiology literature. The radiographs from 107 previously published cases of DF and seven cases from the authors' institution were analyzed to better understand and define its radiographic characteristics. DF was most common in the mandible, pelvis, and femur. A geographic pattern of bone destruction, with a narrow zone of transition and nonsclerotic margins, was seen in 80 (96%) patients with intraosseous DF for whom radiographs were available (83 patients). Internal pseudotrabeculation was seen in 76 (91%). Although widening of the host bone due to gradual apposition of periosteal new bone was common, occurring in 74 (89%) patients, distinct periosteal new bone occurred in only two (2%) patients with DF of intraosseous origin. The cortex was breached in 23 (28%) patients. Three cases of DF arising in the periosteum were identified and were differentiated radiographically from desmoid tumors of intraosseous or soft-tissue origin.