Breast filariasis masquerading as carcinoma: Cytologic diagnosis in two cases.

Filariasis is a common public health problem in the Indian subcontinent. Microfilariae are usually detected in the peripheral circulation; however, the clinical manifestations are related to the lymphatic system primarily. The breast is an uncommon site for filariasis, and the lesion clinically mimics malignancy. We should consider filariasis in the differential diagnoses of breast lumps, especially in endemic areas. Fine-needle aspiration cytology from the breast lump allows easy detection of filarial infection, and this can be managed by medical treatment, thereby avoiding surgical procedures. Copyright:

INTRODUCTION

Breast lumps are commonly encountered in surgical clinical practice and can be broadly classified as benign or malignant.[1] Benign breast lumps are due to fibrocystic disease, fibroadenoma, intraductal papilloma, and abscess. Chronic infections in breast tissue can also present as a palpable lump. Filariasis is a common parasitic infection in tropical countries affecting the lymphatic system of lower extremities, spermatic cord, epididymis, and retroperitoneal tissue. However, extra-lymphatic involvement can rarely occur in the form of swellings in the thyroid, salivary gland, skin, and soft tissue.[23] Filariasis involving breast is extremely rare. Here, we report 2 cases of breast filariasis diagnosed on fine-needle aspiration cytology (FNAC).

CASE REPORT

Case 1

A middle-aged female presented with unilateral, painless left breast lump for 6 months. The lump was firm to hard, measuring 10 cm × 10 cm and involved all quadrants of the breast. The overlying skin was puckered giving Peau D’orange appearance [Figure 1a]. Hence a clinical diagnosis of carcinoma breast was made. FNAC of the lump yielded thin straw-colored fluid. Slides were prepared from the aspirated fluid and stained with Giemsa stain. Microscopic examination revealed clusters of benign ductal epithelial cells. Several microfilaria conforming to the morphology of Wuchereria bancrofti were identified along with mixed inflammatory cells in the background [Figure 1b and c]. No atypical cells were noted in the smears. A final diagnosis of breast filariasis was given based on the cytomorphologic features.

Figure 1

(a) Middle-aged female with left breast lump involving all quadrants and showing peau d’orange appearance. (b and c) Photomicrograph of aspirate showing microfilariae and benign ductal epithelial cell clusters in the background of mixed inflammatory cells (Giemsa stain, ×400)

Case 2

A 67-year-old male, resident of Bihar, presented with right breast lump for 1 year. It measured 3 cm × 3 cm, was hard on palpation and involved the nipple-areola complex [Figure 2a]. Based on the clinical presentation, malignancy was suspected, and FNAC was performed. On aspiration, reddish-brown fluid was obtained. Smears showed sheets and clusters of ductal epithelial cells showing mild atypia at places. Few microfilaria conforming to the morphology of W. bancrofti along with mixed inflammatory infiltrate and macrophages in fluid background admixed with red blood cells were noted [Figure 2b and c]. A final impression of gynecomastia with atypia and filariasis was rendered.

Figure 2

(a) 67-year-old male with right breast lump involving the nipple-areola complex (b) Photomicrograph of aspirate showing microfilaria and ductal epithelial cell cluster in fluid background (Giemsa stain, ×200) (c) Photomicrograph showing microfilaria of Wuchereria bancrofti with rounded anterior end and tapering posterior end free of nuclei (arrow) (Giemsa stain, ×400)

DISCUSSION

Filariasis is a highly prevalent parasitic infection seen in tropical and subtropical nations. In India, it is endemic in states of Bihar, Jharkhand, West Bengal, Uttar Pradesh, Orissa, Kerala, and Gujarat.[4] Most of the cases in India are caused by two species: W. bancrofti (95%) and Brugia malayi (5%).[2] The life cycle of filaria occurs in two hosts: Man, the definitive host and Culex mosquito, the intermediate host. Following a bite by an infected mosquito, microfilaria enters the lymphatic vessels and develop into adult worms, thus disrupting the lymphatic drainage. Intact adult worms produce minimal tissue reaction but can cause obstruction leading to lymphedema.[5] Breast involvement in filariasis is explained by larval contamination of lymphatics in breast tissue causing lymphatic obstruction, lymphangitis, and subsequent fibrosis.[4] The most common site is the upper outer quadrant of the breast. However, the central and periareolar areas can also be involved as seen in case 2. These lesions are usually solitary, subcutaneous in a location with the attachment of overlying skin. There can be skin erythema, edema, and puckering of skin with a characteristic peau d’orange appearance, as seen in case 1.[6] They mimic malignancy and pose a diagnostic challenge. Dead worms can also elicit an inflammatory reaction forming a mass with eosinophilic and granulomatous inflammation, further presenting as a palpable lump.[7] Most of such filarial breast lesions are described in female patients.[6] There are reports of concomitant filariasis in carcinoma breast and there are occasional case reports of breast filariasis in males, including one which mentions filariasis presenting as gynecomastia.[57] Our second patient was an elderly male; his breast lump was clinically suspected to be malignant. However, a diagnosis of gynecomastia with breast filariasis was suggested after the evaluation of cytomorphologic features. The conventional diagnostic methods for filariasis include demonstration of microfilarie in peripheral blood along with eosinophilia.[8] It is uncommon to find these microfilarie on FNAC smears from breast, thyroid, salivary glands, and effusion fluids.[23] Our cases are worth mentioning since both cases were being evaluated for breast malignancy, and filariasis was detected on FNAC. There was no cytomorphologic evidence to favor a neoplastic breast lesion in both cases.

CONCLUSION

Breast filariasis is a rare and unique phenomenon, and its clinical presentation often overlaps with malignancy of the breast. Due to the stark difference in the investigatory as well as treatment modalities of both entities, a possibility of filariasis presenting as a lump in the breast should always be borne in mind, especially in endemic countries like India. FNAC can prove to be a simple, cost-effective, and nonsurgical method for diagnosing breast lumps due to filariasis. This can eliminate the need of unnecessary surgical intervention and allow prompt initiation of antihelminthic treatment.

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Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.