Computed tomography and magnetic resonance imaging of desmoplastic fibroma with simultaneous manifestation in two unusual locations: a case report

<p>Abstract</p> <p>Introduction</p> <p>Desmoplastic fibroma is an extremely rare primary benign bone tumor. It occurs most often in the mandible, followed by the femur and pelvis. To the best of our knowledge, fewer than 200 cases have been described in the published literature. Furthermore, this case is the first report of desmoplastic fibroma with simultaneous presentation in two different locations.</p> <p>Case presentation</p> <p>We present an unusual case of desmoplastic fibroma in a 56-year-old Caucasian man, who presented to our hospital with lumbar pain. Computed tomography and magnetic resonance imaging were performed, demonstrating two lytic expansile lesions affecting both his left iliac bone and his left sacral wing. Curettage and cortical-cancellous grafting was performed, followed by postoperative computed tomography and magnetic resonance imaging.</p> <p>Conclusion</p> <p>Desmoplastic fibroma with unusual and simultaneous manifestations in two different locations has never been reported previously to the best of our knowledge. The purpose of this case report is to present the computed tomography and magnetic resonance imaging features of this rare tumor before and after the surgical treatment. Furthermore, the radiological findings with the description of the characteristics and the clinical presentation of this rare tumor, contribute to the wide spectrum of manifestations of this tumor, in order to recognize it and to have the appropriate management.</p

A rare case of pigmented villonodular synovitis after unicompartmental knee replacement: a case report

Pigmented villonodular synovitis is a benign proliferative disease involving the synovium. Pigmented villonodular synovitis is rare after replacement arthroplasty and has not been recognised and reported as a cause of failure of unicompartmental knee replacement in the literature

Nucleon structure functions and light front dynamics

We present a quark-parton model to describe polarized and unpolarized nucleon structure functions. The twist-two matrix elements for the QCD evolution analysis of lepton-hadron scattering are calculated within a light-front covariant quark model. The relativistic effects in the three-body wave function are discussed for both the polarized and unpolarized cases. Predictions are given for the polarized gluon distributions as will be seen in future experiments

Recurrent tibial intra-cortical osteosarcoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Intra-cortical osteosarcoma is the rarest subtype of osseous-producing tumor. Most reported cases present a low-grade histology with slow progression and good oncological control after adequate treatment. In this report, we describe a case and review the literature to propose adequate treatment.</p> <p>Case presentation</p> <p>We present the case of a 21-year-old Thai woman who was thought to have an intra-cortical osteosarcoma of the right tibia. We performed a wide resection and reconstruction with bone transportation using an Ilizarov external fixator. The tumor recurred five years later at the same site with a similar histology. We performed a new resection and reconstruction by ankle arthrodesis with adjuvant chemotherapy. At the last follow-up, she had remained active and free from disease for seven years.</p> <p>Conclusion</p> <p>This case report of recurrent intra-cortical osteosarcoma describes an atypical presentation. The low-grade histology, adequate surgical margin and adjuvant chemotherapy of the recurrent lesion were favorable factors, and our patient has remained free of any tumor recurrence.</p

Solid variant of aneurysmal bone cyst of the heel: a case report

<p>Abstract</p> <p>Introduction</p> <p>An aneurysmal bone cyst is a benign but often rapidly expanding osteolytic multi-cystic osseous lesion that occurs as a primary, secondary, intra-osseous, extra-osseous, solid or conventional lesion. It frequently coexists with other benign and malignant bone tumors. Although it is considered to be reactive in nature, there is evidence that some aneurysmal bone cysts are true neoplasms. The solid variant of aneurysmal bone cyst is a rare subtype of aneurysmal bone cyst with a preponderance of solid to cystic elements. Such a case affecting the heel, an unusual site, is reported.</p> <p>Case presentation</p> <p>A 26-year-old Caucasian man presented with pain and swelling in his left lower extremity. A plain radiograph demonstrated an intra-osseous, solitary, eccentric mass in the front portion of the left heel. Computed tomography and magnetic resonance imaging scans showed that the lesion appeared to be sub-cortical, solid with a small cystic portion without the characteristic fluid-fluid level detection but with distinct internal septation. Bone images containing fluid-fluid levels are usually produced by aneurysmal bone cysts. The fluid-fluid level due to bleeding within the tumor followed by layering of the blood components based density differences, but it was not seen in our case. An intra-lesional excision was performed. Microscopic examination revealed fibrous septa with spindle cell fibroblastic proliferation, capillaries and extensive areas of mature osteoid and reactive woven bone formation rimmed by osteoblasts. The spindle cells had low mitotic activity, and atypical forms were absent. The histological features of the lesion were consistent with the solid variant of an aneurysmal bone cyst.</p> <p>Conclusion</p> <p>Solid aneurysmal bone cysts have been of great interest to pathologists because they may be mistaken for malignant tumors, mainly in cases of giant cell tumors or osteosarcomas, because of cellularity and variable mitotic activity. It is rather obvious that the correlation of clinical, radiological and histological findings is necessary for the differential diagnosis. The eventual diagnosis is based on microscopic evidence and is made when a predominance of solid to cystic elements is found. The present case is of great interest because of the nature of the neoplasm and the extremely unusual location in which it developed. Pathologists must be alert for such a diagnosis.</p

Tenosynovial giant cell tumors as accidental findings after episodes of distortion of the ankle: two case reports

<p>Abstract</p> <p>Introduction</p> <p>Tenosynovial giant cell tumors are benign tumors of uncertain pathogenesis. They occur in the joints, tendons and synovial bursas. Due to a high recurrence rate of up to 50%, some authors call a giant cell tumor a semimalignant tumor. To date, less than 10 cases of tenosynovial giant cell tumor of the ankle have been published in the international medical literature.</p> <p>Case presentation</p> <p>In this case report, we present two patients with localized tumors that were detected accidentally after the occurrence of ankle sprains with persisting pain in the joint. The tumors were resected by open marginal surgery and regular follow-up examinations were carried out.</p> <p>Conclusions</p> <p>We present an unusual occurrence of a tumor along with a possible follow-up strategy, which has not been previously discussed in the international literature.</p

Magnetic resonance imaging of femoral head development in roentgenographically normal patients

Magnetic resonance images (MRI) of 22 patients with roentgenographically normal hips were reviewed retrospectively and the findings categorized according to age. With increasing maturity, the MR intensity of the femoral heads on spin echo images increased, as marrow fat became a dominant tissue in the head. The femoral head pattern was relatively inhomogeneous, with a broad band of diminished intensity extending in a posteromedial to anterolateral direction, corresponding to the pattern of trabecular bone. The femoral capital epiphyses were visible in younger patients as structures of bright intensity which remained evident through early adulthood. The articular cartilage of the hip joint was noted as a distinctive “halo” around the femoral head. An understanding of the MR pattern of the normal hip will aid in the early recognition of pathologic conditions, such as osteonecrosis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46778/1/256_2004_Article_BF00355555.pd

Giant Intra-Articular Extrasynovial Osteochondroma of the Knee: A Report of Two Cases

We report two cases of a giant extrasynovial osteochondroma of the knee located in the infrapatellar fat pad region, in two females who were 58 and 71 years old respectively. Both patients had noticed the mass many years before our first clinical observation. In both patients, at physical examination a solid, firm and hard mass was palpable in the anterior part of the knee in Hoffa’s fat pad region, and the range of motion of the knee was severely restricted and painful. CT scan examination with 3D-reconstruction showed two large, calcified neoformations behind the patellar tendon, between the apex of the patella and the proximal third of the tibia. In both cases, the mass was completely resected surgically through an anterior longitudinal approach. At histological examination, the excised masses consisted of an outer layer of hyaline cartilage without significant chondrocyte atypia and an inner region of bone trabeculae formed by endochondral ossification. At follow-up, 8 and 4 years after the operation, both patients were pain-free, with complete recovery of the range of motion of the knee and without any clinical or radiographic evidence of recurrence. The authors believe that intra-articular extrasynovial osteochondroma of the knee is a primary metaplasia of Hoffa’s fat pad. Usually, the tumor develops slowly and asymptomatically over many years. The treatment of choice is a marginal resection of the mass, although a biopsy should be considered in some cases. Recurrences are extremely rare