Primary retroperitoneal hydatid cyst masquerading as malignancy

Area of Science:

• Medicine
• Parasitology
• Radiology

Background:

• Hydatid cysts typically affect the liver and lungs.
• Retroperitoneal hydatid cysts are exceptionally rare.
• Malignant masses can be mimicked by retroperitoneal hydatid cysts, complicating diagnosis.

Observation:

• A 61-year-old Tibetan female presented with a complex cystic and solid right retroperitoneal mass.
• The patient had recently traveled to North America.
• Initial presentation mimicked a malignant retroperitoneal tumor.

Findings:

• Echinococcus IgG western blot assay confirmed the diagnosis.
• The patient was diagnosed with a primary retroperitoneal hydatid cyst.
• Imaging studies revealed a complex cystic and solid encapsulated mass.

Implications:

• A high index of suspicion is vital for diagnosing rare retroperitoneal hydatid cysts.
• Serologic testing (Echinococcus IgG) aids in diagnosis.
• Prompt diagnosis prevents complications associated with undiagnosed masses and potential surgical exploration.