Imaging features of intraosseous hemangiomas: beyond the mobile spine and calvarium

OBJECTIVE

Describe imaging features of intraosseous hemangiomas located outside of the mobile spine and calvarium.

MATERIALS AND METHODS

Imaging and medical records were retrospectively reviewed for cases of intraosseous hemangiomas located outside of the calvarium and mobile spine. Evaluation included patient demographics, histologic confirmation, and imaging characteristics.

RESULTS

Thirty-six patients were included (25 F, 11 M; mean age 54 ± 17 years, range 10-84 years) with 37 total lesions (70% axial and 30% appendicular skeleton). Mixed lytic and sclerotic features were identified on 83-85% radiographs and CTs. Amorphous increased density mimicking osteoid matrix was present on 38-45% radiographs and CTs. Classic honeycomb or radial pattern was identified on 45% of CTs. Osseous expansion and cortical permeation were common features. CT identified periosteal reaction in 24% of lesions. All hemangiomas had heterogeneous MRI signal and most moderately or avidly enhanced. Intralesional fat was identified on 78% MRIs, often as a minor component and only detected on 24% of CTs. A soft tissue mass was present on 52% of MRIs. FDG PET/CT mean SUVmax of 3.2 ± 0.6 (range 1.9-5.0). Lesional FDG activity relative to background marrow was increased in 75% of lesions. Lesions with cortical permeation had higher metabolic activity versus those without (3.5 ± 0.7 versus 2.2 ± 0.3, p = 0.041).

CONCLUSION

Intraosseous hemangiomas outside of the mobile spine and calvarium demonstrate more aggressive imaging features compared to vertebral hemangiomas, including cortical permeation, soft tissue mass, amorphous increased density mimicking osteoid matrix, and increased FDG activity.

Surgical approach to a large dumbbell-shaped pelvic lipoma extending through the obturator foramen

Lipomas are the most commonly occurring mesenchymal tumors. We report a technique used to manage a patient with a large dumbbell-shaped pelvic lipoma passing through the obturator foramen. Using the combined expertise of an orthopedic and pelvic surgeon, successful and safe removal of this benign dumbbell-shaped pelvic lipoma was achieved.

Influence of baseline deformity definition on subsequent vertebral fracture risk in postmenopausal women

INTRODUCTION

Approaches for recognizing vertebral fractures remain controversial.

METHODS

An age-stratified population sample of 512 postmenopausal women was followed with serial radiographs for up to 12 years (4455 person-years).

RESULTS

112 women experienced a new vertebral fracture (20% reduction in any vertebral height from baseline) within this study period, for an annual age-adjusted (to US white women > or =50 years of age in 2000) incidence of 23 per 1000. Depending on the morphometric definition used, the prevalence of vertebral deformities at baseline ranged from 3 to 90%. A recent method to standardize vertebral heights produced the best agreement with a qualitative clinical reading of the films [kappa (kappa), 0.53]. Almost all of the different baseline definitions predicted future vertebral fractures, but most of the predictive power was attributable to the severe (e.g., 4 SD) deformities included within more generous (e.g., 3 SD) classifications. Whereas the generous definitions were more sensitive, and the restrictive ones more specific, their overall abilities to predict a new vertebral fracture were roughly comparable as evaluated by the c-index (analogous to the area under an ROC curve).

CONCLUSION

This result suggests that the choice of a morphometry definition depends on the particular application and, in particular, on whether it is more important to maximize sensitivity or specificity.

The multiple faces of lymphoma of the musculoskeletal system

Musculoskeletal manifestations of lymphoma cover a broad spectrum of disease findings with varying degrees of involvement of bone and soft tissue. This pictorial essay will illustrate and review the range of manifestations of lymphoma of the musculoskeletal system. Several unique cases of soft tissue lymphoma will be included to aid with the less familiar and atypical imaging features. Knowledge of the multitude of radiographic manifestations of the disease is critical for enhanced detection, improved diagnostic accuracy and treatment planning, and avoidance of imaging pitfalls.

Unilateral hypertrophy of tensor fascia lata: a soft tissue tumor simulator

OBJECTIVE

To describe the imaging findings in eight cases of unilateral tensor fascia lata (TFL) hypertrophy presenting as soft tissue masses.

DESIGN

Imaging studies and medical charts of eight patients were reviewed retrospectively. The imaging studies included five radiographs, five computed tomography (CT) and six magnetic resonance imaging (MRI) examinations.

RESULTS

The majority of patients (seven of eight) presented with a palpable proximal anterior thigh mass. One patient was asymptomatic and incidentally diagnosed. There were six females and two males. Ages ranged from 27 to 86 years old (mean 61). MRI and CT showed unilateral enlargement of the TFL muscle in all cases.

CONCLUSION

TFL muscle hypertrophy is an uncommon clinical entity, which can simulate a soft tissue tumor. The characteristic appearance on CT or MRI allows a confident diagnosis of muscle hypertrophy to be made, avoiding unnecessary biopsy or surgical intervention.

Episodic snapping of the medial head of the triceps due to weightlifting

We describe two patients who had episodic elbow snapping and ulnar nerve dysesthesias only after weightlifting. These symptoms would disappear soon afterward. The episodic nature of their complaints and findings led to misdiagnosis. We documented by repeated clinical examinations and magnetic resonance imaging that the presence of these symptoms correlated directly with the finding of intermittent, activity-related snapping of the medial triceps. In both patients, the symptoms disappeared when the medial portion of the triceps migrated medially but did not dislocate over the medial epicondyle with elbow flexion. Thus, a minor change in the configuration of the medial portion of the triceps (fluid accumulation) in the same individual at different times can cause intermittent dislocation of the medial triceps. Previous papers dealing with patients with snapping of the medial triceps describe symptoms exacerbated by athletic activities, but the constant finding of snapping on sequential examinations.

Microscopic correlation of radiographically disparate appearing well differentiated osteosarcoma

Well differentiated (low grade) osteosarcomas are often unrecognized and inadequately treated. We report on a patient with a well differentiated osteosarcoma of the tibia that radiographically presented with two strikingly dissimilar appearing juxtaposed lesions. Proximally, the lesion was sclerotic, and distally, osteolytic. The distal lytic half of the lesion showed focal cortical disruption on MR imaging. Microscopic correlation of the resected specimen suggested that the sclerotic component of the lesion had more fibrous dysplasia-like tissue with fewer features of well differentiated osteosarcoma, and the lytic component, features suggestive of well differentiated osteosarcoma. We believe this microscopic interpretation explains the disparate radiographic appearance as all belonging to well differentiated osteosarcoma with varying amounts of fibrous dysplasia-like tissue rather than the development of well differentiated osteosarcoma in fibrous dysplasia.

Acral synovial chondrosarcoma

Acral chondrosarcoma is rare. Synovial chondrosarcoma is even rarer. Synovial chondrosarcoma arising without evidence of pre-existing or concurrent synovial chondromatosis is exceedingly rare. We present a case of acral synovial chondrosarcoma involving both sides of the metacarpophalangeal joint of the thumb in a 69-year-old man. Radiographically, the lesion mimicked gout. On MR imaging, the lobulated contours of the soft tissue mass suggested synovial chondromatosis. Histological examination revealed a chondrosarcoma, which on the basis of imaging findings we present as having arisen from the synovium. The tumor invaded a portion of the cartilage of the metacarpophalangeal joint and equally destroyed the bones of the distal metacarpal and base of the proximal phalanx of the thumb, while sparing the bony joint surfaces.

Malignant vascular lesions of bone: radiologic and pathologic features

The malignant vascular tumors of bone represent an uncommon diverse group of tumors with widely variable clinical and radiographic presentations. Although the radiographic imaging features of the lytic osseous lesions typically seen with this group of tumors are relatively nonspecific, the propensity to develop multifocal disease in an anatomic region is a feature that can be helpful in suggesting the diagnosis of a vascular tumor. The differential diagnosis varies according to the age of the patient and presence of solitary or multifocal disease. The histologic features are variable and range from tumors with vasoformative features to those that mimic mesenchymal neoplasm or metastatic carcinoma. Familiarity with the radiographic and pathologic spectrum of disease is essential for making an accurate diagnosis in this diverse group of neoplasms. This paper will provide a review of the nomenclature for the malignant vascular tumors of bone and discuss the radiographic and pathologic differential diagnosis.

Dedifferentiated clear cell chondrosarcoma

Dedifferentiation, a change in the histologic character and clinical behavior of a tumor to a more immature and aggressive one, occurs in approximately 11% of all chondrosarcomas. The original lesion is usually a low-grade chondrosarcoma. Clear cell chondrosarcoma is a rare cartilaginous tumor of low-grade malignancy with a preference for the ends of long bones. It is usually curable by resection. Recurrence commonly follows inadequate surgery, and metastases to lung, brain, and bones can develop. However, dedifferentiation has not yet been described in association with clear cell chondrosarcoma. Three patients are described who were initially diagnosed as having clear cell chondrosarcoma of the femur. Two were treated with en bloc resection for a clear cell chondrosarcoma. One of these had an undifferentiated sarcoma in a local recurrence after 6 years. In the second, metastasis of the clear cell chondrosarcoma developed 5(1/2) years after surgery; autopsy revealed undifferentiated sarcoma in the lung, heart, and lumbar spine. The third patient had dedifferentiated clear cell chondrosarcoma at the time of resection following the biopsy diagnosis of clear cell chondrosarcoma. All three died with metastatic disease. These three patients represent three different manifestations of dedifferentiation-at initial diagnosis, at recurrence, and at metastasis. To our knowledge, this is the first description of dedifferentiation occurring in clear cell chondrosarcoma.

Recurrent intraneural ganglion cyst of the tibial nerve. Case report

Different theories have evolved to explain the pathogenesis and the cell of origin of intraneural ganglion cysts. Reportedly only three cases of intraneural ganglion of the tibial nerve have been located within the popliteal fossa, and all of these were thought to arise within the nerve. The authors report a case of a recurrent tibial intraneural ganglion in which a connection to the proximal tibiofibular joint was demonstrated on magnetic resonance (MR) images and at surgery. Surgical ligation of the articular branch and evacuation of the cyst led to symptomatic relief, and an MR image obtained 1 year after surgery documented no recurrence. This case reinforces the fact that surgeons need to consider and search for an articular connection in all cases of intraneural ganglia, especially in those that have recurred.

Benign vascular lesions of bone: radiologic and pathologic features

The benign vascular tumors of bone represent a diverse group of tumors that can present with a broad spectrum of clinical signs and symptoms. They can also present a significant diagnostic challenge due to their widely variable radiographic imaging and histologic features. Some of the tumors manifest as clearly benign lesions with tissue-specific diagnostic imaging features, while others have non-specific imaging features that may simulate malignant neoplasm. This article will provide a review of the nomenclature and the characteristic radiographic and pathologic features of the benign vascular lesions of bone. The information will aid in improving our diagnostic accuracy and enhance our understanding of the biologic potential of this diverse group of osseous lesions.

Primary alveolar soft part sarcoma of bone

AIMS

Alveolar soft part sarcoma is a distinct, rare soft tissue tumour occurring primarily within the skeletal muscles or musculofascial planes in young adults. Primary involvement of bone is extremely rare. We report on six patients with alveolar soft part sarcoma occurring primarily in bone.

METHODS AND RESULTS

Thorough clinical and radiographic examinations were done to rule out any other primary site. The patients were four women and two men aged 17-35 years (mean, 24.5 years). The primary site of the tumour was the femur in three patients, the ilium in one and the fibula in two. In one of the patients with fibular involvement, the tibia was also involved by direct extension. Of the long bone lesions, three were centred in the metaphysis and one in the diaphysis. Radiographically, all of the lesions demonstrated an osteolytic pattern of bone destruction with ill-defined margins and a wide zone of transition between the lesion and adjacent normal bone. Microscopically, all tumours showed the typical histological pattern of alveolar soft part sarcoma. Diastase-resistant, periodic acid-Schiff-positive crystalline structures were identified within the cytoplasm and confirmed ultrastructurally. Immunohistochemically, a keratin stain was negative in all cases; there was positive staining for MyoD1 in the cytoplasm but not the nuclei. Distant metastasis developed in four patients; one died.

CONCLUSION

Alveolar soft part sarcoma arising in bone is extraordinarily rare but should be considered in the differential diagnosis of metastatic hypernephroma in a young patient.

Osseous Hodgkin disease

BACKGROUND

Hodgkin disease rarely presents as an osseous lesion, and the majority of patients are found at staging to have concurrent disease in lymph nodes. Many cases of osseous Hodgkin disease have been misdiagnosed on initial biopsy.

METHODS

All cases of Hodgkin disease diagnosed by open bone biopsy at the Mayo Clinic were identified. These included patients with primary osseous tumors, those presenting with multiple sites of involvement (with osseous lesions), and those with recurrence in bone. Recut sections were subjected to immunohistochemical stains to confirm the diagnosis. Clinical data and follow-up information were obtained from patients' charts.

RESULTS

Twenty-five patients (15 males and 10 females with an average age of 37 years) with osseous Hodgkin disease were identified during the years 1927-1996. Three patients had solitary, osseous tumors and two had primary, multifocal, osseous Hodgkin disease without involvement of nonosseous sites. Twelve patients who presented with lesions in osseous sites also had nonosseous tumors detected at staging, and 8 patients had recurrent Hodgkin disease that presented in bone. The majority of patients with primary and recurrent tumors presented only with bone pain; >50% of patients with concurrent osseous and nonosseous disease also had B-type symptoms. Nearly all lesions were in the axial and proximal appendicular skeleton. Radiographic features included osteosclerotic, osteolytic, and mixed lytic/sclerotic patterns. Cortical destruction, periosteal new bone formation, and soft tissue masses were present in 50% of cases. The histologic diagnosis of osseous Hodgkin disease occasionally was problematic; osteomyelitis was the most frequent misdiagnosis. Immunohistochemical stains revealed expression of CD15 and CD30 in neoplastic cells (which were negative for CD45 and B-cell and T-cell antigens) in all but two cases. Involved lymph nodes typically exhibited nodular sclerosis Hodgkin disease. Three patients with primary solitary osseous Hodgkin disease received radiation treatment only; at last follow-up 2 patients were alive at 22 months and 10 years, respectively. Patients with concurrent osseous and nonosseous tumors exhibited a 60% overall survival rate, but at last follow-up all 4 patients diagnosed after 1986 still were alive; those with Hodgkin disease that recurred as osseous lesions had a 60% survival rate at 8 years, but only 1 of the 5 patients diagnosed since 1984 had died of disease.

CONCLUSIONS

Osseous Hodgkin disease typically presents with bone pain, and the majority of patients have concurrent nonosseous lesions detected at staging. Radiographic features of osseous Hodgkin disease vary but indicate an aggressive malignant process. The histologic diagnosis may be problematic; immunohistochemical stains aid in establishing the diagnosis of Hodgkin disease in bone. Survival of patients with osseous Hodgkin disease has been found to be good for the last 10 years.

Primary clear cell sarcoma of bone: a unique site of origin

Clear cell sarcoma is a rare soft tissue neoplasm, accounting for less than 1% of soft tissue sarcomas. We are presenting a case of a clear cell sarcoma of bone which, to our - knowledge, is the only report of a , primary clear cell sarcoma of bone.

Osseous Hodgkin disease

BACKGROUND

Hodgkin disease rarely presents as an osseous lesion, and the majority of patients are found at staging to have concurrent disease in lymph nodes. Many cases of osseous Hodgkin disease have been misdiagnosed on initial biopsy.

METHODS

All cases of Hodgkin disease diagnosed by open bone biopsy at the Mayo Clinic were identified. These included patients with primary osseous tumors, those presenting with multiple sites of involvement (with osseous lesions), and those with recurrence in bone. Recut sections were subjected to immunohistochemical stains to confirm the diagnosis. Clinical data and follow-up information were obtained from patients' charts.

RESULTS

Twenty-five patients (15 males and 10 females with an average age of 37 years) with osseous Hodgkin disease were identified during the years 1927-1996. Three patients had solitary, osseous tumors and two had primary, multifocal, osseous Hodgkin disease without involvement of nonosseous sites. Twelve patients who presented with lesions in osseous sites also had nonosseous tumors detected at staging, and 8 patients had recurrent Hodgkin disease that presented in bone. The majority of patients with primary and recurrent tumors presented only with bone pain; >50% of patients with concurrent osseous and nonosseous disease also had B-type symptoms. Nearly all lesions were in the axial and proximal appendicular skeleton. Radiographic features included osteosclerotic, osteolytic, and mixed lytic/sclerotic patterns. Cortical destruction, periosteal new bone formation, and soft tissue masses were present in 50% of cases. The histologic diagnosis of osseous Hodgkin disease occasionally was problematic; osteomyelitis was the most frequent misdiagnosis. Immunohistochemical stains revealed expression of CD15 and CD30 in neoplastic cells (which were negative for CD45 and B-cell and T-cell antigens) in all but two cases. Involved lymph nodes typically exhibited nodular sclerosis Hodgkin disease. Three patients with primary solitary osseous Hodgkin disease received radiation treatment only; at last follow-up 2 patients were alive at 22 months and 10 years, respectively. Patients with concurrent osseous and nonosseous tumors exhibited a 60% overall survival rate, but at last follow-up all 4 patients diagnosed after 1986 still were alive; those with Hodgkin disease that recurred as osseous lesions had a 60% survival rate at 8 years, but only 1 of the 5 patients diagnosed since 1984 had died of disease.

CONCLUSIONS

Osseous Hodgkin disease typically presents with bone pain, and the majority of patients have concurrent nonosseous lesions detected at staging. Radiographic features of osseous Hodgkin disease vary but indicate an aggressive malignant process. The histologic diagnosis may be problematic; immunohistochemical stains aid in establishing the diagnosis of Hodgkin disease in bone. Survival of patients with osseous Hodgkin disease has been found to be good for the last 10 years.

Tardy sciatic nerve palsy following apophyseal avulsion fracture of the ischial tuberosity. Case report

This 4 1-year-old man presented with a 2-year history of symptoms and signs of sciatic nerve compression. Imaging studies revealed a large ossified fragment within the biceps muscle of the thigh abutting the sciatic nerve at the level of the lesser trochanter. The bony fragment resulted from an unrecognized apophyseal avulsion fracture of the ischial tuberosity, which the patient had sustained while sprinting 27 years earlier. External neurolysis of the sciatic nerve and excision of the mass led to a successful outcome.

Spinal cord localization in the treatment of lung cancer: use of radiographic landmarks

PURPOSE

In the treatment of thoracic malignancies with radiotherapy, the critical dose-limiting structure is the spinal cord. Oblique fields typically are designed to exclude the spinal cord, and by convention, the field edge that shields the spinal cord is placed at the anterior border of the vertebral pedicles. Thus, the purpose of our study was to estimate the distance between the field edge and spinal cord in oblique fields that were designed by using the vertebral pedicle as a radiographic landmark.

METHODS AND MATERIALS

The spinal cord of a cadaver was wrapped in wire, and oblique fields were simulated at 15 degree intervals. The distance from the spinal cord to a field edge placed at the anterior border of the pedicle was measured. In the second investigation, a three-dimensional treatment planning system was used to simulate hypothetical fields using actual patient data from computed tomography (n = 10), and measurements identical to those in the anatomical model were made (n = 1,100).

RESULTS

The results of the anatomical and computed tomographic models were in close agreement (mean difference, 0.6 mm). The computed tomographic model predicted a mean field edge to spinal cord distance of 8.7 mm (95% confidence interval, 5.6-11.8 mm) for 30 degree/150 degree oblique fields and 8.0 mm (95% confidence interval, 4.7-11.7 mm) for 45 degree/135 degree oblique fields. This distance was greatest at levels T-1, T-2, and T-11 (8 to 20% greater).

CONCLUSIONS

The mean distance from a field edge placed at the anterior border of a vertebral pedicle to the spinal cord for commonly used oblique angles constitutes a sufficient margin to account for expected differences in daily positional variations and mechanical uncertainties.

Initial experience with soft-copy display of computed radiography images on three picture archive and communication systems

We recently installed picture archive and communication systems (PACS) from three different vendors on our campus for evaluation. A major part of this evaluation involved assessing the capabilities of these systems for displaying computed radiography (CR) images for primary interpretation. The three PACS provided different functionality for CR image display in terms of availability of the proprietary Fuji CR image processing algorithms, availability of user-specified contrast look-up tables, and application of the processing at the time of CR image capture or image display. We found that the Fuji processing algorithms were important for printing film, but were not necessary for acceptable soft-copy display. Non-linear contrast processing produced superior results compared to simple linear processing (via standard window width and level controls). Display processing was best applied immediately prior to the display operation, as opposed to at the image capture time. This allows the display to be adjusted to demonstrate the full 10-bit range of the CR image, and also allows raw CR data (i.e. not optimized for any particular display device) to be stored in the long-term archive.

Screen-film versus computed radiography imaging of the hand: a direct comparison

OBJECTIVE

Computed radiography of the musculoskeletal system has the potential to become a powerful tool in the practice of diagnostic radiology. It addresses many of the geographic and film-distribution concerns facing diagnostic imaging. We undertook this study to compare and document the quality of computed radiographs and conventional screen-film images before widespread implementation.

MATERIALS AND METHODS

We evaluated clinical images using direct comparison. Bilateral hand images from 50 patients were scored independently by six musculoskeletal radiologists. In each case one hand was imaged with a conventional screen-film technique and the other with computed radiography. Images were masked to eliminate as much bias as possible. The numeric scores assigned to the images by the observers were analyzed using Student's t test.

RESULTS

Computed radiographs were judged with statistical significance to be better than conventional screen-film images in all features judged by the observers, including bone cortex, bone trabeculae, corticomedullary junction, distal phalangeal tuft, soft tissues, fat planes, bone-soft-tissue interface, and overall contrast and density.

CONCLUSION

The statistically significant determination that the image quality of computed radiographs is at least as good as screen-film images allows confident use of computed radiography and enables radiologists to take advantage of its many other practical capabilities related to image distribution, storage, cost, and geographic coverage without sacrificing image quality.

Malignant fibrous histiocytoma of bone. A clinicopathologic study of 81 patients

BACKGROUND

Malignant fibrous histiocytoma of bone, a relatively rare primary malignant neoplasm occurring in bone, is a distinct clinicopathologic entity formerly included in the category of osteosarcoma or fibrosarcoma. A series of patients treated at the Mayo Clinic for malignant fibrous histiocytoma of bone was studied to determine whether the prognosis for this disease is different from that of osteosarcoma and whether treatment should be different.

METHODS

The bone tumor files of the Mayo Clinic were reviewed for examples of malignant fibrous histiocytoma of bone. Clinical records and histologic slides were reviewed for 81 patients. Roentgenograms of 13 patients were available for review.

RESULTS

Patients with malignant fibrous histiocytoma of bone ranged in age from 6 to 81 years. The region most commonly affected was the knee. Seventy-eight percent of the lesions arose de novo and 22% in preexisting conditions. Histologically, most of the tumors were classified as the storiform pleomorphic type, although other histologic subtypes were identified. The prognosis depended on the types of surgical margins involved. Patients with wide or radical margins had a better prognosis than patients in whom the margins were contaminated. Some patients who received radiation therapy alone became long term survivors.

CONCLUSIONS

The overall prognosis for patients with malignant fibrous histiocytoma was not found to be significantly different from that described for patients with osteosarcoma in recent series. However, at least in this small series, some patients with malignant fibrous histiocytoma had a good response to radiation therapy. Osteosarcoma is generally considered radioresistant.

Bone scintigraphy evaluated in diagnosing and staging Langerhans' cell histiocytosis and related disorders

An analysis of patients with proven Langerhans' cell histiocytosis (LCH) was undertaken with the aim of evaluating the role of bone scintigraphy in the diagnosis and staging of LCH.

METHODS

Radiographic skeletal surveys and whole-body bone scintigraphy study results were reviewed for all patients treated at the Mayo Clinic in Rochester, Minnesota during 1965-1994 with histologic proven LCH. All available studies were then reported in a randomized and blinded fashion.

RESULTS

Of the 73 patients with the histologic diagnosis, 56 (76%) had a definite lesion reported on radiographs and subsequent biopsy-proven bone involvement. For this population, the sensitivity and specificity of radiographic survey were 100% and 61%, respectively, compared to 91% and 55% for bone scintigraphy. Solitary bone lesions were reported on 21 radiographic surveys and 24 bone scintigrams. For solitary lesions, radiograph sensitivity and specificity were 95% and 73%, respectively, compared to 88% and 77% for bone scintigraphy. Bone scintigraphy receiver operating characteristic curves showed the region of greatest diagnostic accuracy to be skull, facial bones and mandible (88% sensitivity, 52% specificity). Radiation dosimetry to adult reproductive organs was less favorable for radiographic skeletal survey compared to bone scintigraphy.

CONCLUSION

Our results support the use of radiographic skeletal survey in the initial diagnosis of LCH. Bone scintigraphy may have a role in monitoring a patient's progress in which the initial scintigram and radiographic survey show good correlation.

Pigmented villonodular synovitis of the spine: a clinical, radiological, and morphological study of 12 cases

Cases of pigmented villonodular synovitis (PVNS) that affect the axial skeleton are rare and thus information regarding its natural history, treatment, and prognosis remains limited. To characterize this lesion more fully, the authors reviewed their experience with 12 cases of PVNS of the spine (one of which had been previously reported), then reviewed the 11 cases that previously had been reported, and obtained additional follow-up data in six of them. On the basis of the cumulative data provided by these 22 cases, PVNS of the spine appears to occur over a wide range of ages (21-81 years) and, contrary to what was previously suggested, does not show definite gender predilection (12 women and 10 men). The lesion affects the posterior elements of the vertebrae at all levels and involves the facet joints in 89% of cases. Extension into the epidural spine is frequent (70%). Surgical resection appears to be the treatment of choice. Although PVNS of the spine tends to recur locally (18%), repeat surgical excision appears to be curative.

Langerhans' cell histiocytosis (histiocytosis X) of bone. A clinicopathologic analysis of 263 pediatric and adult cases

BACKGROUND

Langerhans' cell histiocytosis (LCH) of bone is a disorder of histiocytic proliferation with variable and often unpredictable behavior.

METHOD

The authors evaluated the clinical and pathologic features of 263 patients (172 children, 91 adults) with biopsy-proven LCH examined during an 80-year period at the Mayo Clinic. Only patients with bone involvement pathologically and/or radiographically were included in the study. Clinical follow-up was available for 245 patients and ranged from 3 months to 50 years (mean, 12 years; median, 10 years). Chi-square tests were used to determine associations between age, gender, extent of osseous involvement, visceral disease, and pathologic features. Survival analyses were performed by univariate and multivariate Cox regression methods.

RESULTS

Age at presentation ranged from 2 months to 71 years with a clear predominance in children. The most common presenting complaint was pain, often worse at night. The skull was the most frequent osseous site in children and adults. Diabetes insipidus was documented in 40 patients. Forty-four children developed skeletal recurrence and/or new bone lesions, 19 of whom had diabetes insipidus. Fourteen children and 3 adults died either directly or indirectly from LCH. One adult patient developed systemic amyloidosis. All but two of these pediatric patients were 3 years of age or younger at presentation. All children with hepatosplenomegaly (7 patients) and/or thrombocytopenia (9 patients) died. Nine of the 14 children who died presented initially with three or more bone lesions.

CONCLUSIONS

The clinical behavior of LCH of bone is often unpredictable; however, young age at diagnosis, hepatosplenomegaly, thrombocytopenia, and polyostotic (> or = 3 bones involved) disease are associated with a poor prognosis (P < 0.005). Recrudescence in children, but not in adults, strongly correlates with the presence of diabetes insipidus (P < 0.0005).

Lack of evidence for gender bias in the utilization of total hip arthroplasty among Olmsted County, Minnesota residents with osteoarthritis

OBJECTIVE

To evaluate whether women have more advanced osteoarthritis (OA) than men prior to total hip arthroplasty (THA).

METHODS

Preoperative clinical and radiographic severity of hip OA was determined among Olmsted County, Minnesota residents who underwent THA. The time from first radiographic changes and first symptoms to THA was compared between genders.

RESULTS

Fifty men and 80 women underwent their first THA between 1985 and 1990. Men had higher disease activity levels preoperatively; however, 16 other clinical severity variables and 2 summary measures of OA severity were similar for both genders. Men had radiographically more advanced hip OA preoperatively. The time from first symptom of hip OA to THA was similar for both genders, while the time from first radiographic change to THA was significantly longer for men.

CONCLUSION

These results fail to support the hypothesis that hip OA prior to THA is more severe among women compared with men.