A missionary with a swelling on her hip

Abstract

A 58-year-old Norwegian woman was referred from her general practitioner because of a non-tender swelling on her left hip. She used to work as a midwife in the Democratic Republic of the Congo until 5 years ago. Previously she had recovered well from hepatitis A, hepatitis B, and several times from malaria. She had earlier been treated for fi lariasis with diethyl carbamazine. She was in generally good condition, body weight slightly above average, with no other complaints. Just above the left iliac crest there was a palpable non-adherent subcutaneous tumour about 3 × 2 cm with a central more dense area. Ultrasound scan showed a cystic tumour 2 × 1 cm with a surrounding capsule in the muscle layer. The tumour was removed under local anaesthesia (fi gure, A). Histological examination showed a fi brous nodule with worms embedded in granulation tissue with mixed infl ammatory cells including foreign-body giant cells (fi gure, B). The diameter of the worms was about 0·3 mm. Microfi lariae could be seen both inside the uteri of the female worms (fi gure, B, arrows) and in the surrounding fi brous tissue. The appearance was consistent with an onchocercoma. 4 years earlier a skin biopsy had shown unspecifi c lichenoid dermatitis. In retrospect, this possibly could have been secondary to onchocerciasis, but microfi lariae were not be detected in the biopsy. She was given ivermectin 150 µg/kg orally immediately and the same dose was repeated after 1 year. This treatment aff ects only the microfi laria, but not the adult worms. The expected lifetime of an adult worm is 10–15 years and the treatment must be repeated yearly until then. When the nodules are situated in the head and neck area, nodulectomy is recommended to avoid eye involvement, which may result in blindness (“river blindness”). However, there is debate in the medical literature whether nodulectomy from the rest of the body is to be recommended. The patient has returned to the Democratic Republic of the Congo, is in good health, and is continuing on the recommended treatment regimen.