Simultaneous Paragonimus infection involving the breast and lung: A case report

Abstract

Background: Paragonimiasis is a food-borne parasitic infection caused by lung flukes of the genus Paragonimus. Although the most common site of infection is the pleuropulmonary area, the parasite can also reach other parts of the body on its journey from the intestines to the lungs, ending up in locations such as the brain, abdomen, skin, and subcutaneous tissues. Ectopic paragonimiasis is difficult to diagnose due to the rarity of this disease.

Case summary: Here, we report a rare case of simultaneous breast and pulmonary paragonimiasis in a woman presenting painless breast mass and lung nodule with a history of eating raw trout. To confirm the diagnosis, serologic testing and tissue confirmation of the breast mass were performed. The patient was treated with surgical resection of the mass and praziquantel medication.

Conclusion: Ectopic paragonimiasis is difficult to diagnose due to the rarity of this disease. Thus, thorough history-taking and clinical suspicion of parasitic infection are important.

Keywords: Breast mass; Case report; Lung nodule; Paragonimiasis; Paragonimus westermani; Parasitic infection.

Figure 1

Breast mammography and ultrasonography findings. A: Mammography (craniocaudal view) shows an asymmetry at the palpable site of the left inner breast (white arrows); B: Ultrasonography shows a tubular structure inside, approximately 1 cm long and with a circular diameter of 0.2 cm (black arrow).

Figure 2

Gross specimen. A cystic lesion of the excised soft tissue mass, with an irregular inner wall, was about 2.3 cm in longest diameter, and grayish white in color. The parasite was oval-shaped, red in color, and measured to be about 5 mm in longest diameter (arrow).

Figure 3

Paragonimus westermani juvenile worm. The oral sucker is located on one end of the worm, and the ventral sucker is located at its center. The ovary and testes are stained red, and are less finely branched compared to that of adult worms. The intestines of the worm take a brown color and occupy the lateral fields.

Figure 4

Chest computed tomography findings. 18 mm sized elongated nodule at left upper lobe of the lung (arrow).