Abstract
INTRODUCTION: Filariasis is an endemic disease with worldwide distribution in tropical and subtropical regions. It is uncommon in Qatar. The conventional diagnostic procedure is the demonstration of microfilaria in blood smears. Even with its high incidence, it is unusual to detect microfilaria in fine needle aspiration cytology (FNAC) smears. Although the 'filarial dance sign' is rarely documented, it remains a classical ultrasonographic sign in lymphatic filariasis. CASE PRESENTATION: We present a case of a 38-year-old male patient with fever, chills, shortness of breath and a tender warm swelling on his right thigh. Ultrasound of the thigh lesion showed the classical filarial dance sign. Subsequently FNAC from the lesion documented microfilaria in spite of absent peripheral blood eosinophilia and microfilaria. The patient underwent an incision and drainage of the thigh lesion and was treated with ivermectin and diethylcarbamazine. He was subsequently admitted to the medical ward and discharged home after two weeks in a stable condition. CONCLUSION: This case report illustrates the importance of diagnostic tools like ultrasound and FNAC along with a high index of clinical suspicion while evaluating patients presenting with unusual signs and symptoms. We would like to highlight the rarity of filarial presentation in a nonendemic country like Qatar. This case is unique since microfilaria was demonstrated in the pus aspirated from the thigh abscess and showed the filarial dance sign by ultrasound along with involvement of the pleura and pericardium.