Malignant Peritoneal Mesothelioma with Latent Tuberculosis Infection.

Malignant peritoneal mesothelioma (MPM) is a rare malignant tumor with peritoneal thickening. Tuberculous peritonitis also shows peritoneal thickening, so differentiating between the two is important but difficult if latent tuberculosis infection (LTBI) is present. We herein report a patient with MPM and LTBI. A 79-year-old man was diagnosed with peritoneal thickening on computed tomography. Interferon gamma release assay (IGRA) results were positive, suggesting tuberculous peritonitis. He underwent a laparoscopic omental biopsy and was diagnosed with MPM, which can occur together with LTBI. If peritoneal thickening is observed, an IGRA should be performed early, and the possibility of LTBI should be considered.