Aneurysmal bone cyst of the fibula

Aneurysmal bone cysts are benign, expansile lesions that are not at all uncommon in the lower extremity. These lesions are difficult to recognize clinically. This paper is a thorough review of the current literature regarding aneurysmal bone cysts. After this review, one should be able to diagnose and appropriately treat aneurysmal bone cysts. Also provided is a case report with classic histologic, clinical, and radiographic findings that was treated by en bloc resection.     

Aneurysmal bone cyst in a dog

A one-year-old male mongrel dog was referred to the Veterinary Clinic with a several-week history of lameness and pain of the right front leg. Radiological examination of the right humerus revealed a cystic lesion at the distal end of the bone; the lesion was nodular in a gross appearance. Histologically, the nodular lesion consisted of large areas of haemorrhage and thick fibrous trabeculae mixed with a variably dilated cavernous structure of blood vessels attributed to haemangiosarcoma. Based on these findings, aneurysmal bone cyst secondary to the tumour was diagnosed.     

Aneurysmal bone cyst and giant cell tumor of the foot

From 1950 to 1994, 257 cases of benign bone tumors of the foot were treated at the Bone Tumor Center of the Rizzoli Institute. Aneurysmal bone cysts (ABC) and giant cell tumors (GCT) are rare and often they are misdiagnosed. To define the clinical and radiographic features useful for diagnosis, x-rays of 24 ABCs and 21 GCTs of the foot were reviewed. Adding our series to the cases reported in the literature, the only important clinical data that emerged was the average age of patients affected by ABC and GCT (15 and 27 years, respectively). ABCs localized in small tarsal bones were rare (6%), whereas 19% of GCTs were found in this site. The eccentric, round shape of a lytic lesion was more characteristic of GCT. An aggressive pattern of radiographic bone destruction was observed more frequently in GCT than in ABC (P = 0.01). Septation was seen in both tumors. Typical of ABC was a sharp and trabeculated margin, whereas GCT had an ill-defined edge with normal cancellous bone (P = 0.007). The growth of ABCs often expanded the cortex, while GCTs eroded, thinned, and broke the cortical bone (P = 0.001). A saucerized cortex was observed only in ABCs. A bony shelf was more characteristic of ABC than of GCT (P = 0.002). Pathologic fractures (67%) and joint involvement, evaluated by computed tomography and magnetic resonance imaging (83%), were more frequent in GCTs, whereas fluid levels were more frequently observed in ABCs (47%). The majority of the tumors were stage 2, but GCTs represented 70% of stage 3 aggressive lesions.     

Aneurysmal bone cyst involving the distal phalanx of a child

BACKGROUND: The synthesis of nitric oxide (NO) in the colonic mucosa of patients affected by ulcerative colitis (UC) has been previously investigated using indirect measurements of enzyme activity and non-specific measurements of luminal NO gas. The aim of this study was to determine unequivocally if luminal NO gas in active UC is present in greater concentrations than in healthy control subjects. METHODS: Luminal gas was collected from eight patients with active UC and eight healthy volunteers. NO gas concentration was measured using diode laser spectroscopy. RESULTS: NO gas was detected in four of eight patients with active UC (range 0.13-1.1 nmol) and none of the healthy control subjects. CONCLUSION: NO gas is present in greater concentrations in patients with active UC than in control subjects. This supports the view that mucosal NO synthesis is increased in ulcerative colitis.     

Extraosseous aneurysmal bone cyst

Methanol is a common ingredient in many household products and intoxication can arise easily from inadvertent exposure through ingestion, inhalation or percutaneous absorption. We analysed ten cases of methanol poisoning who presented with visual, neurological and gastrointestinal symptoms, of whom one died and nine were successfully detoxified with ethanol and bicarbonate infusions. Clinical symptoms were not found to correlate with the severity of poisoning. Serum methanol level was found to correlate significantly with arterial pH (correlation coefficient -0.74, p = 0.014) and serum standard bicarbonate levels (correlation coefficient -0.87, p = 0.001). We found that an arterial pH of < 7.33 or a serum standard bicarbonate of < 20 mmol/L correlated well with a serum methanol level of > 45 mg/dL ie severe poisoning (X2 test with Yate's correction factor, p < 0.02). We conclude that arterial pH or serum standard bicarbonate levels can be used as surrogate indicators of the severity of methanol poisoning. They can be used to guide physicians in the method of detoxification (ie whether intravenous or oral ethanol or dialysis should be used) whilst awaiting serum methanol levels in cases where the index of suspicion for methanol poisoning is high. Some cases of severe poisoning can be successfully treated with oral ethanol if the intravenous form is not available.     

Aneurysmal bone cysts of the maxilla: a clinicopathologic review

PURPOSE: This study evaluated the significant differences in clinicopathologic features of aneurysmal bone cyst in the maxilla and mandible. MATERIALS AND METHODS: A search of the literature showed 30 recorded maxillary cases, and these together with one previously unrecorded case formed the basis of the study. RESULTS: There were no differences in the age and sex incidence. Only two patients complained of pain, and no patient complained of tenderness. No patient gave a history of trauma. Swelling was present in virtually every patient. In seven cases, there was tooth mobility or migration of teeth. Two patients complained of paresthesia. Four patients presented with proptosis, two of whom complained of diplopia. The radiographic appearance of the aneurysmal bone cyst is suggestive but not diagnostic. CONCLUSION: Although these differences do not enable the clinician to make a definitive diagnosis before biopsy, they have important implications for management.     

Local arthroscopic bone grafting of a juxta-articular glenoid bone cyst

This report describes a rare, juxta-articular bone cyst of the posterior glenoid that developed after a fracture of the glenoid in a 38-year-old male. The patient had persistent pain, popping and stiffness of his right shoulder for 3 years, and failed to improve after a nonoperative rehabilitation program. At arthroscopy, the senior author transported an autogenous bone graft from the bare area of the humeral head to fill the glenoid cyst arthroscopically. At second-look arthroscopy approximately 1 year after the index procedure, the bone graft had consolidated within the original cystic defect and the surface was covered with fibrocartilage. The graft harvest site posteriorly on the humeral head had healed with a small amount of scar tissue at the articular margin. Comfortable motion and function were restored.     

Growth arrest resulting from unicameral bone cyst

Using a 51Cr release assay, we investigated Fas-mediated cytotoxicity of peripheral blood CD4+ T cells of patients with human T-lymphotropic virus type-I (HTLV-I)-associated myelopathy (HAM) against T98G, a glioblastoma cell line which expresses Fas. Cytotoxic activity of CD4+ T cells against T98G was significantly higher in HAM patients than in controls. Moreover, when CD4+ T cells of HAM patients were preincubated with a monoclonal antibody to human Fas ligand (FasL), cytotoxic activity against T98G was significantly suppressed. These results suggest that damage to nervous tissues by the Fas/FasL system is involved in the pathogenesis of HAM.     

Case report: calcification within aneurysmal bone cyst

Aneurysmal bone cyst (ABC) usually affects older children or young adults. The radiological appearance is of a purely osteolytic expansile metaphyseal lesion with thinned out cortex and internal septations. We present a case of ABC in a 5-year-old girl which showed internal calcification and was initially diagnosed as enchondroma. However, pathological examination revealed typical appearance of ABC with large area of dystrophic calcification.     

Histopathologic and radiographic findings of the simple bone cyst

Biosynthesis of extracellular alkaline guanyl-specific RNase by Bacillus circulans (RNase Bci) was studied. Synthesis of the enzyme by the culture started in the late exponential phase and was inhibited by inorganic phosphate and glucose, in contrast to the biosynthesis of its structural and functional homologue, RNase Ba (barnase) of B. amyloliquefaciens. It is suggested that differences in the regulation of the biosynthesis of RNase Bci and Ba are related to different structures of their gene promoters.     

Post-traumatic bone cyst: a case of the floating fragment

We report a case of an intraosseous foreign body leading to the formation of a bone cyst. The cyst was identified 20 years after the initial injury and was found to contain the foreign body. No infection was found.