Summary Background Gastrointestinal tuberculosis (TB) is a rare manifestation in low TB-incidence countries such as Austria. It is usually seen in immunocompromised patients or in migrants being more susceptible for extrapulmonary disease manifestations. Case description We report a very rare manifestation of severe gastrointestinal TB in a 49-year-old previously healthy man from Upper Austria. Endoscopy showed a large tumor mass obstructing about 2/3 of the lumen of the cecum. Positron emission tomography/computed tomography scan revealed not only a high metabolic activity in the tumor mass, but also active pulmonary lesions in both upper lung lobes. Bronchial secretion showed acid-fast bacilli in the microscopy and polymerase chain reaction was positive for M. tuberculosis complex. Phenotypic resistance testing showed no resistance for first-line anti-TB drugs. Treatment with isoniazid, rifampicin, pyrazinamide and ethambutol was initiated. Based on therapeutic drug monitoring, the standard treatment regime was adapted to rifampicin high dose. TB treatment was well tolerated and the patient achieved relapse-free cure one year after the end of treatment. Conclusion Gastrointestinal involvement mimicking an intestinal tumor is a very rare TB manifestation in previously healthy Austrians. However, it should be kept in mind due to increasing migration from countries with higher rates of extrapulmonary TB and due to an increasing number of immunocompromised patients. TB telephone consultations can support medical professionals in the diagnosis and the management of complex TB patients. TB management is currently at a transitional stage from a programmatic to personalized management concept including therapeutic drug monitoring or biomarker-guided treatment duration to achieve relapse-free cure.