Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Laboratory | Radiology description | Radiology images | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Differential diagnosis | Additional referencesCite this page: Asirvatham JR, Jorns JM. Filariasis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastfilariasis.html. Accessed December 12th, 2019.
Definition / general
- Lymphatic filariasis is caused by nematodes that inhabit the lymphatic vessels and lymph nodes of a human host
Terminology
- 3 filarial species cause lymphatic filariasis in humans:
- Wuchereria bancrofti is the most common cause of infections worldwide
- Brugia malayi and Brugia timori can be the causative organisms in Asia
- Dirofilarial infection of the breast has also been reported (Breast Care (Basel) 2012;7:487)
Epidemiology
- Endemic in Central Africa and Southeast Asia
- Humans are the only host for W. bancrofti filariasis
- Brugian filariasis can affect wild and domestic animals
Sites
- Inguinal lymph nodes and lower extremities are most commonly involved
- Can affect the arms, breast and genitalia
Pathophysiology
- Microfilaria enter the lymphatic vessels of mammary gland and develop into adult worms, disrupting lymphatic drainage
- Intact adult worms produce minimal tissue reaction but can cause obstruction leading to lymphedema (peau d'orange skin: mimics malignancy)
- Degenerating / dying worms provoke an inflammatory reaction forming a mass with eosinophilic and granulomatous inflammation
- Some of the inflammation is in response to antigens of the endosymbiotic bacteria Wolbachia, which the filarial worms contain
- Secondary lymphangitis and fibrosis may result
- Chronic inflammation leads to nonpitting edema, hyperpigmentation and hyperkeratosis and possibly superimposed bacterial infection
- Adult filiaria mate and release microfilaria into the blood
Etiology
- Infection is transmitted by mosquito vectors; humans are definitive hosts (CDC: Parasites - Lymphatic Filariasis [Accessed 17 August 2018])
Clinical features
- Unilateral, soft, nontender swelling, commonly in upper outer quadrant
- May be mobile from quadrant to quadrant and mimic fibroadenoma
- May be associated with enlarged lymph nodes and simulate breast carcinoma
- Overlying skin has induration, hyperpigmentation, dilated veins
Diagnosis
- Peripheral smear examination for microfilaria
- Excision biopsy
Laboratory
- Serological testing
- Elevated eosinophils and serum IgG4
Radiology description
- Real time ultrasound may show movement of filarial worms ("filarial dance")
Radiology images
Case reports
- 35 year old man with filariasis presenting as gynecomastia (Breast J 2012;18:83)
- 59 year old woman (Indian J Pathol Microbiol 2008;51:85)
- 69 year old woman (Radiology 2002;222:515)
- 2 adult women with dirofilariasis of breast (Diagn Cytopathol 2002;26:22)
- Woman with filariasis of the breast three years after visiting India (Arch Pathol Lab Med 1987;111:757)
Treatment
- Diethylcarbamazine to kill microfilaria
- Surgical treatment may be an option for genital and breast disease
Microscopic (histologic) description
- Cross section of adult worm with surrounding chronic, eosinophilic and granulomatous inflammation, fibrosis
Microscopic (histologic) images
Cytology description
- Fragments of adult worms, gravid female worms, microfilariae, macrophages, variable epithelioid granulomas, other acute or chronic inflammatory cells (Diagn Cytopathol 2011;39:8)
Differential diagnosis
Additional references
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