Feline small cell lymphosarcoma versus inflammatory bowel disease: diagnostic challenges.

Inflammatory bowel disease (IBD) and small cell lymphosarcoma (SCLSA) are common causes of chronic gastrointestinal (GI) tract disease in cats. The history, clinical signs, and results of blood work and imaging for these conditions are nonspecific and often overlap. After a thorough diagnostic workup and treatment trials to rule out other conditions, a definitive diagnosis requires histopathologic evaluation of GI tract biopsy specimens. Full-thickness tissue samples appear to be superior to endoscopic biopsy samples in providing an accurate diagnosis. Adding advanced diagnostics such as polymerase chain reaction and immunohistochemistry to traditional histopathology may improve the diagnostic utility of small samples such as the ones obtained via endoscopy. Treatment of and prognosis for IBD and SCLSA are discussed in a companion article.