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.

Lipoma arborescens: comparison of typical and atypical disease presentations.

AIM: To determine whether the aetiology differed between typical cases of lipoma arborescens with unilateral knee involvement and atypical cases involving joints other than the knee, polyarticular disease, and disease outside of the knee joint. MATERIALS AND METHODS: Cases of lipoma arborescens involving the knee joint were evaluated for the distribution of the disease and severity of degenerative arthritis. Joints other than the knee were evaluated for the presence and severity of degenerative arthritis, and the distribution was classified as either intra-articular, extra-articular, or both. Clinical history was reviewed for patient age at presentation, a history of inflammatory arthritis, diabetes mellitus, and known steroid use. Fisher's exact test was used to determine whether there was a statistically significant difference between typical and atypical presentations of the disease. RESULTS: Lipoma arborescens was identified in 45 joints in 39 patients. Twenty-eight patients were classified as "typical" and 11 patients had "atypical" disease. There was no significant difference in age at presentation, presence of degenerative arthritis, or known inflammatory arthritis when comparing typical and atypical presentations of the disease. CONCLUSION: Twenty-eight percent of patients in the present study had atypical presentation of lipoma arborescens with multifocal lipoma arborescens or disease in joints other than the knee. There was no significant difference in age at presentation, presence of degenerative arthritis, or known inflammatory arthritis when comparing typical and atypical presentations of the disease. Of the 39 patients, only three had no evidence of degenerative arthritis, which suggests that many cases of lipoma arborescens are secondary to chronic reactive change in association with degenerative arthritis.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.