Nonsurgical Management of a Caudal Mediastinal Granuloma

A 3 yr old female springer spaniel presented with a 3-day history of pyrexia, lethargy, and a mild cough. A year prior, the dog had undergone surgical removal of a grass seed from her sublumbar muscles. Computed tomography of the thorax revealed the presence of a caudal mediastinal mass closely associated with the esophagus and diaphragm. A median sternotomy was performed, but the mass proved nonresectable. Biopsy results confirmed a chronic granuloma, and the culture isolated Escherichia coli spp. The patient was treated with long-term antibiotics and the response was followed with computed tomography, with the mass completely resolved in 6 mo. Caudal mediastinal masses are a rare entity in veterinary medicine. Most of the masses are abscesses or granulomas caused by migrating foreign bodies. Surgical excision or debridement is considered the preferred treatment. This case report describes the successful long-term management of a nonresectable mediastinal granuloma through medical intervention. Medical management can have successful outcomes when surgical excision is not feasible.