Omental dirofilariasis caused by Dirofilaria repens; visceralisation in a patient with diabetes mellitus

Visceral manifestations due to zoonotic Dirofilaria repens have not been reported in Sri Lanka. A 46-year-old woman with type 2 diabetes mellitus presented with abdominal pain and ankle oedema. There was ultrasonographic evidence of ascites and laparoscopy was performed to exclude malignancy. Cytology of ascitic fluid revealed inflammatory cells, and histology of omental biopsy showed a cross-section of a worm within a granuloma. The presence of cuticular ridges, tall coelomyarian muscles, prominent lateral chords and the presence of developing eggs within a uterine tube was compatible with female Dirofilaria repens. Blood was negative for microfilariae. She was treated with halfdose diethylcarbamazine (DEC) for fourteen days. Ascites persisted, albeit treatment. Therefore, repeat laparoscopy and infracolic omentectomy were performed. Repeat cytology and histology revealed no abnormalities, which was attributed to the complete removal of the worm. Whether immunosuppression with diabetes mellitus led to visceralisation of dirofilariasis is a concern.