Can Peritoneal Biopsy Diagnose Atypical Cases of Familial Mediterranean Fever?: A Case Report

Familial Mediterranean Fever (FMF) is a prevalent inherited monogenic autoinflammatory disease that predominantly affects populations from the Mediterranean basin. It is typically characterized by the recurrence of fever episodes and abdominal pain accompanied by recurrent short-lived inflammatory attacks that usually resolve spontaneously within 1-3 days. It is uncommon to see ascites with large amounts of peritoneal fluid as a manifestation of FMF.

A 36-year-old Arab female presented with generalized abdominal pain and bloating. No family history of FMF. Analysis of peritoneal fluid identified low-grade ascites. A CT scan was performed, which did not reveal any suspicious lesions. Laparoscopic surgery was undertaken to rule out the differential diagnoses and obtain a peritoneal biopsy, even though the periton had a normal visual appearance. Histopathological examination of the biopsy specimens was compatible with a diagnosis of FMF, after other differential diagnoses were ruled out. The patient showed significant improvement within a month of taking colchicine. The ascites resolved progressively and completely, affirming the FMF diagnosis.

The occurrence of chronic ascites in a patient requires the consideration of FMF among the differential diagnoses. A diagnosis of FMF can also be suspected through a peritoneal biopsy, which may be sufficient for diagnosis without the need for genetic testing. Additionally, the patient's response to colchicine therapy can be considered for confirmation, as demonstrated in our case. Future research should focus on considering the inclusion of peritoneal biopsy among the diagnostic criteria for FMF particularly in cases with non-specific presentations.