The coexistence of mediastinal, splenic, renal, and peritoneal locations is an exceptional presentation. Multimodal imaging is essential for: Detecting lesions, mapping all locations and guiding the therapeutic strategy.

Imaging plays a crucial role in the diagnosis and assessment of multifocal hydatidosis.
In the mediastinum, chest CT typically reveals a thin-walled, non-enhancing hypodense cystic mass that may exert compressive effects on adjacent structures such as the heart or great vessels [2]. MRI provides complementary information, showing a hypo-intense signal on T1-weighted images and a hyper-intense signal on T2-weighted sequences, with thin internal septations and improved visualization of anatomical relationships [3].

In the spleen, ultrasound generally demonstrates a well-defined, rounded anechoic lesion with internal septations, while CT shows a hypodense mass that may occasionally present peripheral calcifications. On MRI, the cystic nature appears clearly with a high T2 signal and a well-defined wall.

Renal involvement, representing approximately 2–4% of all hydatid localizations, typically appears on ultrasound as a cystic lesion with internal septations and, in some cases, distortion of the excretory system [5]. Abdominal CT reveals a hypodense, multivesicular cyst with possible wall calcifications and frequent cortical extension [6]. MRI confirms the cystic pattern, showing a low signal on T1 and a high signal on T2, without internal enhancement, although the appearance may mimic a cystic renal tumor (Bosniak category II–III) [7].

Peritoneal hydatidosis is most often secondary to the rupture or dissemination of a hepatic or splenic cyst. Ultrasound identifies multiple intraperitoneal cystic formations, either free or adherent to adjacent organs [8]. On CT, these lesions appear as scattered hypodense cysts, sometimes exhibiting a multivesicular configuration. MRI, with its superior contrast resolution, shows marked T2 hyperintensity, facilitating differentiation from compartmentalized ascites or mesothelial cysts [9].

The differential diagnosis of multifocal cystic lesions includes several entities depending on the site of involvement. In the spleen, the main differentials are epidermoid cysts, bacterial abscesses, and cystic metastases. Mediastinal cystic lesions may mimic bronchogenic cysts, lymphangiomas, or cystic germ cell tumors. In the kidney, differential considerations include cystic renal tumors categorized by the Bosniak classification and pyogenic abscesses. Peritoneal cystic formations can be confused with compartmentalized ascites, mesothelial cysts, or peritoneal carcinomatosis. However, the presence of radiological features characteristic of hydatid disease—such as multivesicularity, internal septations, peripheral calcifications, and the coexistence of lesions in multiple locations—strongly supports the diagnosis of hydatidosis.

The management of hydatid disease combines medical and surgical approaches, depending on the location, size, and impact of the cysts.

Medical treatment relies primarily on benzimidazole derivatives, with albendazole being the drug of choice, administered at a dose of 10–15 mg/kg/day divided into two daily doses, in 28-day cycles separated by 14-day intervals. Mebendazole can be used as an alternative in cases of intolerance. The main objectives of antiparasitic therapy are to reduce the viability of the parasite prior to surgery, prevent secondary dissemination, and treat small or inoperable cystic lesions. Close biological monitoring of hepatic function and blood count is mandatory throughout treatment to detect potential drug-related toxicity.

Surgical treatment remains essential in cases where cysts are large, symptomatic, or exert compressive effects. The approach varies according to the site of involvement.
For mediastinal localizations, surgery via thoracotomy or video-assisted thoracoscopic surgery (VATS) is indicated, aiming for complete excision of the cyst without rupture to prevent dissemination or anaphylactic shock. The residual cavity should be irrigated with a scolicidal solution such as hypertonic saline, hydrogen peroxide, or 20% sodium chloride.

For splenic, renal, or peritoneal localizations, surgical management includes cystectomy or partial/total pericystectomy, depending on accessibility and extent. Total splenectomy is performed in cases of diffuse splenic involvement, while partial or total nephrectomy may be necessary for destructive renal forms. Peritoneal cysts are managed by simple excision or drainage, depending on the degree of dissemination.