Extrapulmonary tuberculosis as a cause of complex perianal fistula disease.

Extrapulmonary tuberculosis (TB) in the gastrointestinal tract is a rare, but yet an essential differential diagnosis to patients with complex fistula disease, since the initiation of immunosuppressive therapy for presumed Crohn's disease can lead to a fulminant course of TB. This case report presents a young Danish woman with a progressive complex fistula disease, where cause and treatment were uncovered by interprofessional collaboration between pulmonologists, gastroenterologists and surgeons including a screening test for TB as well as multiple biopsies from the anal fistula tissue.