1/18. osteolysis in a cementless, second generation metal-on-metal hip replacement.A 65-year-old man with osteoarthritis of the hip underwent a cementless total hip replacement with a modern generation, metal-on-metal bearing. Two years later the patient presented with localized osteolysis at the tip of the femoral stem. At the time of revision, the stem was found to be well-fixed. Extensive analyses of the bearing surfaces and periprosthetic tissues were done. There was minimal bearing surface wear and only small numbers of inflammatory cells, such as macrophages, in the tissues, and it was concluded that this was not a typical case of particle-induced osteolysis. All cultures and laboratory studies were negative for infection. This case report supports the multifactorial nature of osteolysis, which includes the osteolytic potential of joint fluid access to and fluid pressures within, the effective joint space.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/18. echinococcosis granulosus/cysticus of the tibia.Hydatid disease is caused by the parasitic tapeworm echinococcus. There are three species: E. granulosus, E. alveolaris and E. voegeli. Only E. alveolaris and E. granulosus are important for human infections. These two species are totally divergent in their manner of infestation. Hydatid disease is a rare parasitic disease that primary involves the liver and the lung. Skeletal disease is rare, accounting for less than 2% of all hydatid lesions, and often presents as a clinical and radiologic diagnostic problem. The skeletal involvement is usually due to secondary extension after haematogenous spread of the infection. The vertebral column, the pelvis and the skull are most commonly involved. Treatment is also difficult because of the invasive nature of bony involvement and the spillage of fluid with subsequent contamination seeding. We present a case of primary hyatid cyst of the tibia. We point out the importance of considering osseous hydatidosis in the differential diagnosis of destructive bone lesions and the necessity of radical resection.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/18. Benign fibrous histiocytoma of the posterior arch of C1 in a 6-year-old boy: a case report.STUDY DESIGN: Presented is a unique case report of a rare bone tumor: a benign fibrous histiocytoma (BFH) located in the posterior arch of C1 in a 6-year-old child. OBJECTIVE: To describe a benign fibrous histiocytoma of bone and the differential diagnostic considerations based on the authors' case report. SUMMARY OF BACKGROUND DATA: A BFH is a rare tumor composed of varying degree of fibroblast-like spindle cells, foam cells, and multinucleated giant cells. Approximately 86 cases have been reported in literature. Its exact nature remains somewhat controversial. A lesion may be designated a benign fibrous histiocytoma based on clinical, radiographic, and microscopic criteria. MATERIALS AND methods: The clinical symptoms, plain radiographs, computerized tomography (CT), magnetic resonance images (MRI), bone scintigraphy, and histologic section of the lesion are discussed, evaluated, and compared with other benign bone lesions. RESULTS: This case is, to the best of the authors' knowledge, the first benign fibrous histiocytoma to be reported in the cervical spine of a child. Various benign lesions such as nonossifying fibroma, giant-cell tumor, fibrous dysplasia, aneurysmal bone cyst, osteoblastoma, and eosinophilic granuloma are included in the differential diagnosis. CONCLUSION: Benign fibrous histiocytoma is a rare skeletal tumor. Because of this and its nonpathognomonic microscopic features, the diagnosis can be somewhat troublesome. However, by systematically reviewing patient's symptoms, tumor location, and radiographic and microscopic characteristics, other benign lesions can be eliminated. The diagnosis of a BFH is one of exclusion.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/18. Glandular odontogenic cyst: case report and review of the literature.Glandular odontogenic cyst (GOC) is a rare developmental cyst of the jaws. It is included in the world health organization (WHO) histologic typing of odontogenic tumors under the terms glandular odontogenic cyst or sialo-odontogenic cyst. The most common site of occurrence is the anterior mandible, and it occurs mostly in middle-aged people. A predilection for men is observed. Clinical findings are not specific, and an asymptomatic swelling is frequently observed. A unilocular or multilocular, well-defined radiolucency is usually seen. The microscopic features of GOC, particularly the morphology of the epithelium, strongly suggest an origin from the remains of dental lamina. GOC has an unpredictable and potentially aggressive nature, which may indicate a high tendency of recurrence. The treatment of choice is still controversial, varying from a curettage to local block excision. A long-term follow-up should be carried out. The aim of this article is to report a case of glandular odontogenic cyst that recurred four times and to emphasize the importance of long-term follow-up. The origin, epidemiology, clinical and radiographic aspects, and treatment of the GOC are also discussed.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/18. Nerve sheath tumors involving the sacrum. Case report and classification scheme.Nerve sheath tumors that involve the sacrum are rare. Delayed presentation is common because of their slow-growing nature, the permissive surrounding anatomical environment, and nonspecific symptoms. Consequently, these tumors are usually of considerable size at the time of diagnosis. The authors discuss a case of a sacral nerve sheath tumor. They also propose a classification scheme for these tumors based on their location with respect to the sacrum into three types (Types I-III). Type I tumors are confined to the sacrum; Type II originate within the sacrum but then locally metastasize through the anterior and posterior sacral walls into the presacral and subcutaneous spaces, respectively; and Type III are located primarily in the presacral/retroperitoneal area. The overwhelming majority of sacral nerve sheath tumors are schwannomas. Neurofibromas and malignant nerve sheath tumors are exceedingly rare. Regardless of their histological features, the goal of treatment is complete excision. Adjuvant radiotherapy may be used in patients in whom resection was subtotal. Approaches to the sacrum can generally be classified as anterior or posterior. Type I tumors may be resected via a posterior approach alone, Type III may require an anterior approach, and Type II tumors usually require combined anterior-posterior surgery.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/18. Acute lymphocytic leukemia in adolescence with multiple osteolytic lesions and hypercalcemia mediated by lymphoblast-producing parathyroid hormone-related peptide: a case report and review of the literature.BACKGROUND: Osteopathy is one of the common initial symptoms of acute lymphocytic leukemia (ALL) in children and adolescents, but multiple osteolysis accompanied by hypercalcemia is rarely observed. PROCEDURE: We treated a 14-year-old female who had multiple osteolytic lesions and hypercalcemia at initial onset of ALL. In this case we examined some humoral factors, which are known to associate with hypercalcemia in malignancies. RESULTS: parathyroid hormone-related peptide (PTHrP) was elevated in serum, and reverse transcriptase-polymerase chain reaction and immunohistochemistry revealed that the lymphoblasts produced PTHrP directly. Other humoral factors related to hypercalcemia were not detected. ALL relapsed in the bone marrow 3 months after achieving complete remission, and hypercalcemia and elevation of serum PTHrP were also observed. A second remission could not be achieved and hypercalcemia continued. The patient received allogeneic bone marrow transplantation. The serum calcium level became normal after the conditioning therapy. Before engraftment, however, the patient died of infection. CONCLUSIONS: The present case suggests that blast-producing PTHrP might be associated with multiple osteolytic lesions and hypercalcemia. PTHrP expressed in the lymphoblasts may, in itself, confer a survival advantage to lymphoblasts and contribute to the refractory nature of the disease.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/18. Joint contractures and acroosteolysis in ehlers-danlos syndrome type IV.Among a series of 10 patients with ehlers-danlos syndrome Type IV, several had peripheral joint contractures and 3 had acroosteolysis. The consequent deformities simulated the appearance of chronic inflammatory joint disease and hence, patients with this rare syndrome may come to the attention of rheumatologists. Recognition of ehlers-danlos syndrome Type IV is important because of the risk of early death from arterial rupture. The syndrome is also of theoretical importance as an "experiment of nature" illustrating functional consequences of deficiency of Type III collagen.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/18. Juvenile hyaline fibromatosis. A 15-year follow-up.A 37-year-old man was seen because of juvenile hyaline fibromatosis that had been present since he was 2 to 3 years old. His case illustrates the progressive nature of the disease, and during the years attempts to treat the condition were as mutilating in some cases as the disease itself.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/18. Paraproteinaemia plus osteolytic lesions in typical hairy-cell leukaemia.Most cases of hairy-cell leukaemia (HCL) involve proliferations of neoplastic B lymphocytes. In rare cases, M-proteins or osteolytic lesions have been documented in patients with HCL. In this study two patients with typical HCL are reported in whom both paraproteinaemia and osteolytic lesions of the femoral neck developed. In one of the patients the production of the M-protein by hairy cells could be established. In the other patient, at autopsy no signs of myeloma were found. The hairy cells from inside the osteolytic lesion had the same immunological phenotype as hairy cells from the peripheral blood, the spleen, and other parts of the bone marrow. These cases once more confirm the B-cell nature of many cases of HCL, and show that hairy cells can have functional capacities usually attributed to much more mature B lymphocytes, i.e. plasma cells.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/18. Mucin impaction tumor of the paranasal sinuses: a new clinical entity?A variety of uncommon benign lesions occur in the paranasal sinuses and have been reported to masquerade as carcinomas. Nearly all of such cases have been limited to the frontal, sphenoid, and ethmoid sinuses with an isolated report of maxillary sinus involvement. The classic roentgenologic picture is that of bony destruction. Heretofore described destructive lesions of the maxillary sinus include the mucocele, mucous retention cyst, pseudocyst, pyocele and cholesteatoma. This report deals with a previously undescribed entity, the mucin impaction tumor located in a septate maxillary sinus. This inflammatory, non-neoplastic tumor-like condition, presents as chronic sinusitis with periorbital edema, malar swelling and tenderness. Radiologic examination reveals total destruction of the bony walls of the nose, of the orbital rim and floor and of the maxillary sinus. The importance of recognizing this lesion lies in its benign nature but destructive capabilities. The destruction may possibly be accounted for by its anatomical origin in the septate sinus. Repeated surgical intervention may also serve to predispose or potentiate development of these lesions. Its resolution after adequate surgical extirpation and its place in the differential diagnosis of antral lesions are worthy of emphasis.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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