Adult filarial worm in the aspirate from a breast lump mimicking fibroadenosis.

Filariasis is major public health hazard particularly in tropical countries like India. The presence of microfilaria using fine needle aspiration cytology has been reported from various sites. However, the presence of the adult gravid filarial worm with a surrounding host response has rarely been reported on breast aspirates. Here, we report a unique case in which aspiration cytology from a breast lump clinically suspicious of fibroadenosis of the breast, showed adult filarial worms with numerous microfilariae and a granulomatous inflammatory host response. The filarial worm appears to be ubiquitous in endemic areas, and the presence of an unexplained granulomatous lesion in breast should prompt a careful consideration of the filarial etiology in our country. Therapy with diethylcarbamazine, albendazole, and antibiotics are sufficient for treatment of this type of lesion.

INTRODUCTION

Filariasis is an infectious parasitic disease and is regarded as a major public health problem in the tropical countries of Africa, Southern America, and Asia. Transmitted by the Culex mosquito, humans serve as the definitive host. Wuchereria bancrofti accounts for more than 90% of the cases of the world followed by Brugia malayi and Brugia timori.[1] The adult W. bancrofti may produce lesions in various sites by affecting the lymphatics of the lower limbs, spermatic cord, epididymis, testis, retroperitoneum, and female breast.[2] However, finding adult gravid worms by fine needle aspiration cytology (FNAC) of breast with granulomatous inflammation has rarely been reported. Here, we report the case of a 30-year-old lady who presented with a tender breast lump with the clinical suspicion of fibroadenosis.

CASE REPORT

A 30-year-old lady presented to the outpatient department with a painful swelling in her left breast. She had first noticed the swelling 2 weeks back and stated that the size was increasing slowly. There was no history of cyclical mastalgia. The patient was suffering from fever and had already undergone routine examination of peripheral blood. The report showed a hemoglobin level of 10.8 g/dl with a normal total leucocyte count and mild eosinophilia (differential count of eosinophil - 08%). The erythrocyte sedimentation rate (ESR) was high, the value being 80 mm in the first hour. On examination, a 2 × 2 cm swelling was seen in the upper outer quadrant of the left breast. The swelling was soft with vague margins and was mildly tender.

FNAC was performed by a 24 G needle fitted to a 10 cc syringe and yielded a granular material admixed with a turbid fluid. The smears were stained with the May–Grunwald–Giemsa (MGG) stain and hematoxylin and eosin (H and E) stain. The cellular smears from the aspirate showed gravid adult filarial worms with a preserved outer cuticle layer. Numerous microfilariae were seen coming out from the paired uteri. The microfilariae incited a foreign body reaction in the form of multinucleated giant cells and granulomas [Figures 1 and 2]. The microfilariae were rounded anteriorly and uniformly tapering posteriorly with a clear space free of nuclei at the caudal end – thus morphologically resembling W. bancrofti. There was presence of few ductal cells of breast as well. The fluid-mixed background was dirty with a fair number of neutrophils, few eosinophils, cyst macrophages, and cellular debris. A diagnosis of filariasis of breast with granulomatous and foreign body reaction was made. A midnight blood sample taken after 2 days showed motile microfilariae on wet mount preparation. The patient was treated with amoxicillin-clavulinic acid, albendazole, and diethylcarbamazine (DEC). The swelling had disappeared when the patient came for follow-up after 2 weeks.

Figure 1

Microphotograph showing numerous microfilariae coming out of the paired uteri of the adult filarial worm (H and E stain, ×100 magnification). Inset, lower left: microphotograph showing granuloma adjacent to a microfilaria. Inset, upper right: microphotograph showing a multinucleated giant cell adjacent to a microfilaria (H and E stain, ×400 magnification)

Figure 2

Microphotograph showing numerous microfilariae coming out of the gravid adult filarial worm. A foreign body giant cell is indicated by a black arrow (MGG stain, ×100 magnification)

DISCUSSION

The medical literature documents filariasis back to 600 BC by Sustruta who recognized the clinical manifestation of elephan-tiasis and referred it as elephantiasis arabicum.[3] Filariasis is a global problem and India is also badly hit by it. The heavily infected areas in our country are found in Uttar Pradesh, Bihar, Jharkhand, Andhra Pradesh, Orissa, Tamil Nadu, Kerala, and Gujarat.[4]

There are eight species of microfilaria of which W. bancrofti, B. Malayi, and B. timori are responsible for lymphatic filariasis. Of these, the first two are common in India and they show nocturnal periodicity. Humans serve as the definitive host while infected mosquitos (Culex quinquefasciatus for bancroftian filariasis and Mansonia mosquitos for brugian filariasis) serve as the vectors. The adult worms harbor in the lymphatic system of man. The males are about 40 mm long and the females range between 50 and 100 mm in length. The viviparous females usually give rise to as many as 50,000 microfilariae per day.[4] The parasites usually involve the lymphatics and cause fever, lymphangitis, lymphadenitis, and lymphedema resulting in elephantiasis. Besides they also cause hydrocele, chyluria, epididymoorchitis, etc. In spite of various reports stating the presence of microfilaria using aspiration cytology in various sites like spermatic cord, epididymis, testis, retroperitoneum,[1] soft tissue,[2] breast,[5-7] etc., reports of adult worms in cytological aspirates are sparse. Pandit et al.[8] and Azad, et al.[9] reported the presence of adult filarial worms in soft tissue swellings. Satpathi et al.[10] reported a rare case of adult filarial worms in the breast aspirate. Thus, barring a few reports, the presence of an adult gravid filarial worm in a breast lesion by FNAC is an extremely rare finding. The presence of a host response in the form of foreign body reaction and granuloma formation is also a unique finding. Patrikar et al.[1] reported a case of breast filariasis where cytological smears did not yield any granuloma but the excised breast lump showed histopathological features of an adult filarial worm with surrounding granulomatous inflammatory reaction. They opined that although the presence of filarial granuloma is rare in India, the presence of any unexplained granuloma of breast should prompt a search for a filarial etiology.[1] The patient responded well to a combined treatment of antibiotics, albendazole, and a 12-day oral course of DEC. The patient did not develop any complication during the treatment period. The breast swelling gradually resolved within 2 weeks of the initiation of therapy.