Iatrogenic Kaposi sarcoma of the small bowel in Crohn's disease following short-term use of immunomodulators: a case report and review of the literature.

BACKGROUND

Kaposi sarcoma is a vascular tumor highly related to human herpesvirus-8 and Kaposi sarcoma-associated herpesvirus. Kaposi sarcoma usually manifests as skin or mucosal lesions; involvement in visceral organs such as the gastrointestinal tract is rare. Kaposi sarcoma can occur in immunocompromised patients receiving immunosuppressive therapy, in which case it is known as iatrogenic Kaposi sarcoma or drug-induced Kaposi sarcoma. Intestinal Kaposi sarcoma in patients with inflammatory bowel disease is extremely rare.

CASE PRESENTATION

A 46-year-old East Asian male with recently diagnosed Crohn's disease was administered azathioprine and prednisolone; however, the patient complained of persistent abdominal pain and diarrhea following treatment. Endoscopy revealed small bowel Kaposi sarcoma. The patient was treated with systemic chemotherapy successfully without relapse.

CONCLUSIONS

This is the fifth case of Kaposi sarcoma developed over the small intestine in a patient with Crohn's disease following administration of immunomodulators. Additionally, this case indicated that even short-term immunomodulator use can induce Kaposi sarcoma in patients with inflammatory bowel disease. Thus, in patients with inflammatory bowel disease, if symptoms are aggravated or do not abate after immunomodulators prescription, and before intending to upgrade immunomodulators, endoscopy should be considered. Finally, chemotherapy can also be considered if both medication withdrawal and surgical intervention are not feasible.