Thyroid cancer and T lymphoblastic leukemia in Crohn disease: a case report and literature review.

The effectiveness of the tumor necrosis-α (TNF-α) blockade has changed the treatment of several chronic inflammatory diseases, including inflammatory bowel disease; however, this treatment also has disadvantages. The use of immunosuppressants in combination with infliximab has been associated with greater risk of developing malignant neoplasms. Herein, we report the case of a 33-year-old ethnic Korean man with Crohn disease (CD) who developed papillary thyroid carcinoma (PTC) and, subsequently, T-cell acute lymphoblastic leukemia (ALL) after approximately 16.0 years of immunosuppressant therapy and 5.5 years of infliximab therapy. To our knowledge, this is the first case described in the literature of 2 different malignant neoplasms, 1 of hematologic origin and the other involving the solid organs, in a patient with CD. Through a systematic literature review, we found 28 cases of acute leukemia in adult patients with CD, of whom 22 had myeloid leukemia and 6 had lymphoid leukemia. Half of the patients with ALL underwent TNF-α-blocker therapy in combination with thiopurines.