Occult metastatic intestinal adenocarcinoma resulting in pathological fracture of the proximal humerus.
Authors: Jann H W, Breshears M A, Allison R W, Pechman R D, Day J, Hart J C A, Moorman V J
Journal: Equine veterinary journal
Summary
# Editorial Summary A case of occult intestinal adenocarcinoma in a horse presented with an atypical clinical picture: pathological fracture of the proximal humerus accompanied by sequestrum formation, clinical signs that typically prompt investigation for osteomyelitis rather than neoplasia. The diagnostic workup included radiographic evaluation, histopathology of bone samples, and examination of metastatic lesions distributed across multiple sites, revealing the underlying malignancy only after conventional differential diagnoses had been exhausted. This presentation is exceptionally rare—intestinal adenocarcinomas themselves occur infrequently in equine practice, and metastatic bone involvement with fracture is unusual—making the case instructive for practitioners encountering similar presentations. The key clinical implication is that whilst sequestrum formation and pathological fractures should prompt initial investigation for infectious causes, the differential must remain broad enough to encompass metastatic neoplastic disease, particularly when clinical responses to conventional treatments are poor or radiographic findings prove inconsistent with osteomyelitis. Heightened awareness of this diagnostic possibility may improve recognition and allow earlier palliative management decisions for affected horses.
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Practical Takeaways
- •When presented with sequestrum formation and pathological fracture in the proximal humerus, consider metastatic neoplasia in your differential diagnosis, not just infectious osteomyelitis
- •Intestinal adenocarcinomas are rare in horses but can metastasize to bone; clinical presentation may be atypical and warrant thorough investigation
- •Request appropriate diagnostic imaging and consider biopsy when radiographic findings are inconsistent with typical osteomyelitis patterns
Key Findings
- •A case of occult metastatic intestinal adenocarcinoma in a horse presented with pathological fracture of the proximal humerus
- •Sequestrum formation and pathological fracture were initially suspected to be osteomyelitis based on radiographic appearance
- •Differential diagnosis of metastatic disease should be considered when sequestrum formation and pathological fracture are identified in horses