First case of human peritoneal cysticercosis mimicking peritoneal carcinosis: necessity of laparoscopy and histologic assessment for the correct diagnosis.

Introduction. Correct diagnosis of peritoneal infectious disease can be extremely difficult due to non-specific clinical features. Thus, careful assessment with thorough histopathological work-up is essential. Here, we report the first case of human peritoneal cysticercosis mimicking peritoneal carcinosis. Case presentation. The patient presented with recurring ascites and a tumour in the Douglas cavity accompanied by elevated tumour markers. There were no signs of systemic infection. On laparoscopy, the tumour was resected completely. Histology revealed a granulomatous reaction and a diagnosis suspicious of tuberculosis was made. Only after additional sections, avital cestode-fragments were visible and Taenia martis DNA was detected. Further staging by computerized tomography scan of the lung and brain turned out negative and the patient recovered quickly. Conclusion. Laparoscopy and histopathological examination can be extremely helpful for correct diagnosis and management in uncertain recurrent ascites. This case clearly demonstrates that orphan infectious diseases should also be considered. Only complete histopathological examination with serial sections and additional molecular testing can lead to the appropriate diagnosis.