A pregnant breast lump

Once inoculated through the skin, the larvae enter the lymphatics and proceed to regional lymph nodes. Adult worms can cause lymphangitis by way of a hypersensitivity reaction, followed by fibrosis and disruption of lymphatic drainage. Lymph stasis results in soft tissue oedema, hyperkeratosis, pigmentary changes, and chronic skin ulceration.4There were no skin changes in our case; a local fibrotic reaction produced a single nodule. The worm in the specimen was pregnant, with microfilariae visible both within the uterus and in the free space outside it (high power field). Differential diagnosis include dirofilaria and onchocerciasis. However, the former is always sterile in man and the latter is associated with microfilariae infiltrating connective tissue. In addition, the ridges along the worm's cuticle is most consistent with Wuchereria spp, as previously described in endemic areas in fine-needle aspirate specimens.5