Introduction

Hydatid disease (HD) is a zoonosis caused by the larval form of the Echinococcus granulosus parasites in which human is the intermediate host (1). Hydatid cysts mainly develop in the liver (75%) and lungs (15%) and less frequently (10%) in other internal organs (2). Hydatid cyst of the breast is very rare and patients usually present with painless swelling of the breast. Since it is usually asymptomatic, it is diagnosed during routine mammographic examinations (2,3). Herein, we present a case of HD involving the liver, kidney and breast with findings of mammography (MG), ultrasonography (USG) and computed tomography (CT).

Case

A 45-year-old woman was referred from the general surgery outpatient clinic to the radiology department for routine breast screening and non-specific abdominal pain. On physical examination, there was no abnormal abdominal examination finding except for a scar of a previous right subcostal incision from a liver hydatid cyst surgery. Breast examination revealed a palpable mobile mass with an elastic consistency in the upper outer quadrant of the left breast. Breast USG examination revealed a heterogeneous hyperechoic lesion (Type 4) of approximately 2x2 cm in size in the left breast at the 2 o’clock position having smooth borders and a folded thick membrane view inside, with acoustic enhancement (Figure 1). Abdominal USG showed a heterogeneous hyperechoic lesion (Type 4) of approximately 5x3.5 cm in size in the upper part of the right kidney which located cortically, had smooth borders and a folded thick membrane view inside and acoustic enhancement. In the segment 4 of the liver, there was a cystic lesion (Type 2) of approximately 6.5x6 cm in size with separated thick membrane inside demonstrating acoustic enhancement (Figure 2). The patient had a history of surgery for a hepatic hydatid cyst. When the patient’s previous radiological examinations were reviewed, her previous MG showed an opacity measuring approximately 2x2 cm with smooth borders and lucent folds inside (Figure 3) in the left upper quadrant of the left breast. Abdominal CT revealed a thick-walled cystic lesion of 6.5x6 cm in size with detached thick membrane inside in the segment 4 of the liver. Besides, there was a thick-walled heterogeneous lesion measuring approximately 5x3.5 cm with smooth borders and folded thick membrane inside in the upper part of the right kidney (Figure 4). Liver function tests and biochemical tests were within the normal limits. Hemagglutination test was negative for HD. Surgical treatment was recommended but the patient refused. Informed consent was obtained from the patient.

Discussion

Hydatid disease is still a serious public health problem in endemic areas. It is a tissue infestation caused by the larval stage of a parasite named E. granulosus (4). HD of the breast is very rare even in endemic areas and constitutes only 0.27% of all cases. The breast may be involved primarily or can be a part of disseminated hydatidosis (5). Since the primary disease presented as a hepatic lesion in our patient, the lesion in the breast was a part of disseminated hydatidosis. Hydatid cysts of the breast are usually caused by hematogenous spread, but there is also the possibility of retrograde passage of E. granulosus eggs from the milk ducts during breastfeeding (5). Cystic lesions of the breast, fibroadenoma, phyllodes tumor and breast abscess should be kept in mind in the differential diagnosis of HD. Clinically, HD of the breast is usually painless. There is no specific physical examination finding (2). Our patient also presented to the hospital for routine screening and the hydatid cyst of the breast was incidentally detected.

Renal involvement is usually associated with systemic involvement, while isolated renal HD is a very rare condition. However, the kidney is the most frequently involved organ in the genitourinary system (6).

USG shows complex cysts in all patients. USG is the primary imaging modality for classification of hydatid cysts. During USG examination, similar to that in other organs, hydatid cysts in the breast are evaluated as well-bordered structures with mixed echo characteristics containing multi-cystic and solid areas (2). They are difficult to diagnose unless cyst membranes or fluid levels are observed on USG images. On MG, they are demonstrated as homogeneous, non-specific, round lesions with smooth-contours. Annular structures around a radiopaque, well-countered lesion on MG are also indicative of HD. Presence of hydatid cysts in other organs supports the diagnosis of breast HD (7,8). There was no difficulty in diagnosing breast HD in our patient, because the appearance of the lesion on USG and on the previous MG was typical and she had a medical history of HD.

CT and USG provide similar information. However, CT shows the location and depth of the cyst in the liver more accurately. CT scans show the presence of daughter cysts and exogenous cysts. MRI provides the structural details of the hepatic hydatid cyst. MRI findings are non-specific. Cystic lesions are hyperintense on T₂-weighted images and hypointense on T₁-weighted images. Contrast MRI shows a cystic lesion with peripheral enhancement (9,10).

The common treatment options are surgical treatment, medical treatment, puncture, aspiration, injection, and re-aspiration. In medical treatment, praziquantel can be used with benzimidazoles such as mebendazole and albendazole. Medical treatment with albendazole and mebendazole is carried out prior to and after the surgery to ensure cyst sterilization, to reduce the risk of anaphylaxis and prevent recurrence after surgery.

In conclusion, HD is a serious public health problem in endemic regions. It affects many organs through intraoperative transmission or by hematogenous spread. Breast and renal hydatid cysts are rare; hence, the differential diagnosis is challenging. It should be kept in mind in patients with hepatic HD.

Authorship Contributions

Concept: P.G.B., A.B. Design: P.G.B., Ab.B. Data Collection or Processing: P.G.B., A.B. Analysis or Interpretation: P.G.B., Ab.B. Literature Search: P.G.B., A.B. Writing: P.G.B., A.B.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study received no financial support.