Evaluation of focal bone lesions: basic principles and clinical scenarios

Sterile osteomyelitis in the ulnar diaphysis of a young indoor cat

Case summary

A 3-year-old neutered male indoor British Shorthair cat was referred for a 2-week history of intermittent right forelimb lameness. Radiographic examination showed a diaphyseal monostotic, expansile, fusiform, lytic lesion in the right ulna. CT further defined the lesion and also demonstrated ipsilateral pulmonary consolidation. Histology was conclusive of osteomyelitis, and microbiology and fluorescence in situ hybridisation analysis (FISH) were negative on aerobic and anaerobic bacterial culture, as well as fungal culture. Clinical and radiographic improvement was seen after anti-inflammatory treatment and a short initial period of antibiosis.

Relevance and novel information

This is an unusual monostotic diaphyseal cortical location for osteomyelitis in cats and, moreover, may represent a rare case of sterile osteomyelitis. To our knowledge, non-traumatic osteomyelitis in this location in cats has not been reported in the veterinary literature.

Prognostic and proliferative evaluation of ameloblastoma based on radiographic boundary

Ameloblastoma is a benign odontogenic tumor with an aggressive biological behavior, and the surgical treatment frequently results in failure for the postoperative recurrence. The aim of this article was to investigate whether the proliferative ability and prognosis of ameloblastoma could be evaluated by the radiographic boundary. The ameloblastoma cases treated by the conservative therapy in our hospital between 1981 and 2001 were divided into three groups based on the nature of the radiographic borders of the lesions. The biologic behavior was evaluated by Ki-67 antibody immunohistochemically. Comparisons of prognosis and Ki-67 expression were carried out by statistic methods. There were 24 cases of well-defined edge with sclerosis (group I), 41 cases of well-defined edge without sclerosis (group II) and 32 cases of ill-defined edge (group III). The recurrent rates were 29.2% in group I, 43.9% in group II and 62.5% in group III (P<0.05). The cells in group III expressed the highest Ki-67 level (P<0.05). The radiographic boundary could be used as one of indicators in evaluating the proliferative ability of ameloblastoma and the patient's prognosis, which was consistent with Ki-67 expression.

The role of the plain radiograph in the characterisation of soft tissue tumours

A radiograph is often the first investigation to be requested when a patient presents with limb pain or a mass. Whilst we do not advocate that this is the only investigation to be employed in the evaluation of such patients, a working knowledge of the variety of abnormal findings that can present in the soft tissues on radiographs remains useful. We reviewed the radiographic findings of soft tissue masses from a prospectively compiled database of all such lesions presenting to a specialist orthopaedic oncology service over the past 8 years. Of the cohort of 1,058 individuals with a proven soft tissue tumour, 454 had had a radiograph taken of the affected area. Of these, 281 (62%) patients had a positive radiographic finding. The most common findings were a visible soft tissue mass (n = 141), the presence of calcification (n = 76), fat (n = 32) and evidence of bone involvement (n = 62). More than one finding was sometimes present in the same patient. These findings were present in both benign and malignant tumours. This review article describes the incidence and diagnostic relevance of these plain film findings for suspected soft tissue tumours.

Primary malignancies mistaken for pseudotumours in haemophilic patients

Pseudotumours are a rare complication of haemophilia. Surgery undertaken for pseudotumour on a lesion that is subsequently found to be malignant can be expected to adversely affect patient outcome. We present six case reports found from a literature search of patients with haemophilia who underwent surgery on what was a primary malignancy misdiagnosed as a pseudotumour and give a subsequent discussion.