Aneurysmal bone cysts are rare skeletal tumors that most commonly occur in the first two decades of life. They primarily develop about the knee but may arise in any portion of the axial or appendicular skeleton. Pathogenesis of these tumors remains controversial and may be vascular, traumatic, or genetic. Radiographic features include a dilated, radiolucent lesion typically located within the m...

Immune-mediated Arthritides in Humans Humans suffer from several immune-mediated arthritides. These diseases are segregated based mainly by their clinical features and patterns of joint involvement, as their underlying mechanisms are different. Rheumatoid arthritis (RA) is characterized by erosions of small joints, particularly those of wrists (intercarpal joints), ankles (intertarsal joints), ...

BACKGROUND Malignant melanoma of the conjunctiva is an extremely rare non-cutaneous neoplasm with infrequent skeletal metastatic spread. CASE PRESENTATION We present the case of a 54 year old female Caucasian patient with osseous metastases originating from a malignant melanoma of her right conjunctiva. Metastatic deposits were identified in the left humeral diaphysis and left tibial metaphys...

Trost M.E., Kommers G.D., Brown C.C., Barros C.S.L., Irigoyen L.F., Fighera R.A., Inkelmann M.A. & Silva T.M. 2012. Primary bone neoplasms in dogs: 90 cases. Pesquisa Veterinária Brasileira 32(12):1329-1335. Departamento de Patologia, Universidade Federal de Santa Maria, Camobi, Santa Maria, RS 97105-900, Brazil. E-mail: [email protected] A retrospective study of necropsy and biopsy cases o...

Adamantinoma is a rare primary bone tumor that commonly arises in the jaw and has also been described in the appendicular skeleton such as the tibia. We report 2 cases of tibial adamantinomas that were originally misdiagnosed; one as fibrous dysplasia of the tibia and the other as a cutaneous eccrine carcinoma in a groin mass, which was metastatic adamantinoma to the inguinal lymph nodes. Such ...

Giant cell rich osteosarcoma is a relatively unusual histological form of osteosarcoma, common lesion usually presenting in the long bones of the appendicular skeleton. The occurrence in the mandible is exceptional rare. Histologically, this tumor tends to be a highly anaplastic, pleomorphic tumor in which the tumor cells may be: plasmacytoid, fusiform, ovoid, small round cells, clear cells, mo...

Copyright © 2009 by the Congress of Neurological Surgeons Benign and malignant tumors of the spinal column and spinal cord are a common and costly clinical problem, causing significant morbidity. Metastatic disease to the spine is the most common presentation; approximately 160 000 new spinal metastases are diagnosed in the United States each year, resulting in considerable pain, functional imp...

Myofibromas are mesenchymal tumors showing myofibroblastic differentiation and found most frequently in the head and neck region. While several cases of myofibromas have been reported in adults, they have not been described in long bones of the appendicular skeleton. We describe an otherwise healthy young woman who presented with a progressive incapacitating pain in her right shin. Imaging stud...

An 87 year-old white female presented with a two-year history of intermittent discomfort in her left foot. PET-CT identified intense18F-fluorodeoxyglucose (FDG) uptake corresponding to the lesion. Histology of a fine needle aspiration and open biopsy were consistent with a benign giant cell tumor (GCT) of the bone. GCT of bone is an uncommon primary tumor typically presenting as a benign solita...

CASE SUMMARY A 4-month-old cat had bilateral swellings of the mandible, maxilla, humerus and femur, and angular deviations in the axial and appendicular skeleton. The biochemical profile indicated hypercalcemia, hyperphosphatemia and increased parathyroid hormone levels. Because of the poor prognosis, the cat was euthanized. At necropsy, malleable and fragile bones, associated with numerous cys...