Colchicine toxicity - Distinct morphologic findings in gastrointestinal biopsies

Colchicine is an alkaloid with antimitotic ability used to treat a variety of medical conditions. Colchicine toxicity can result in multiorgan failure and death. The histopathologic features of colchicine, toxicity in gastroi ntestinal biopsies have not been reported. Twenty-one gastrointestinal muco sal biopsies obtained from nine patients receiving oral colchicine therapy were studied. Immunohistochemical staining for Ki67 proliferation antigen w as performed, and medical records of each patient were reviewed. All patien ts had a history of gout. Four patients with chronic renal failure also had clinical evidence of colchicine toxicity, and the other five patients did not. Distinct morphologic changes, seen as metaphase mitoses, epithelial ps eudo stratification, and loss of polarity, were seen in biopsy material fro m 4 of 4 (100%) patients with clinical colchicine toxicity. Three of these four cases (75%) also contained abundant crypt apoptotic bodies. These morp hologic features were best seen in the biopsies from duodenum and gastric a ntrum, with relative sparing of the gastric body in the upper gastrointesti nal tract, Ki67 staining demonstrated an expansion of the proliferating reg ion in three available cases with clinical colchicine toxicity. These disti nctive morphologic features were not seen in the five patients without clin ical colchicine toxicity. These results indicate that colchicine toxicity c an produce diagnostic morphologic features in gastrointestinal mucosal biop sies. Recognition of these features is important because colchicine toxicit y can be fatal if undiagnosed clinically.