Breast ductal carcinoma with coexistent microfilaria: Diagnosed on cytology.

Filariasis is a major health problem of the tropical and subtropical regions, but filariae are also found in temperate climates. The disease is endemic all over India and microfilariae have been observed as coincidental findings with inflammatory conditions and neoplastic lesions. We report a rare case of a 40-year-old female from a nonendemic area presenting with lump in the left breast. The skin overlying the mass was fungating and ulcerated. Ipsilateral axillary lymph nodes were palpable. Fine-needle aspiration cytology revealed highly cellular smears having ductal epithelial cells arranged in groups, tight clusters, and scattered singly. Cells were large, having pleomorphic round to oval nuclei with prominent nucleoli. Along with these tumor cells, sheathed microfilariae of Wuchureria bancrofti were seen, suggesting a diagnosis of ductal carcinoma with coexistent microfilaria of W. bancrofti. Findings were confirmed on histopathology of the resected specimen following modified radical mastectomy. Coexistent pathologies should always be considered while reporting.