[Hydatid cyst of the chest wall mimicking metastatic colon cancer]

Chest wall hydatidosis, rare even in the endemic countries, represents 0.09 to 0.3 % of all cases of thoracic echinococcosis. The authors report the case of a 76 year-old man presenting a chest wall mass 4 years after surgery for colic carcinoma. The mass presented both hypoechoic and hyperechoic structures in the ultrasound chest echography. Therefore, metastastic colon cancer was suspected. The pathological study of the mass revealed hydatid membranes. Thoracic tomodensitometry supported the diagnosis of costovertebral and soft tissue hydatid cysts. The patient underwent the surgical resection of two rib arches, a transverse apophysis and the neighbouring soft tissue associated with pre- and post-surgical albendazole. No clinical manifestations were noted in the follow-up after 1 year.