Peritonitis From Ruptured Lipid-Poor Dermoid: Struma Ovarii

Area of Science:

• Gynecology
• Oncology
• Radiology

Background:

• Mature cystic teratoma (MCT), also known as dermoid cysts, are common benign ovarian germ cell tumors, predominantly affecting premenopausal women.
• These tumors arise from germ cells and can contain derivatives of all three germ layers, with ectodermal components often being predominant.

Observation:

• Rupture of a dermoid cyst, occurring in 1-2% of cases, can lead to chemical aseptic peritonitis due to spillage of cyst contents.
• Clinical presentation typically involves diffuse abdominal or pelvic pain and distension.
• Diagnosis can be challenging when dermoid cysts exhibit minimal or no fat, which is present in only 4-7% of cases.

Findings:

• This report details a rare case of a spontaneously ruptured left ovarian dermoid cyst that was lipid-poor and rich in thyroid tissue.
• The patient presented with symptoms consistent with chemical peritonitis.
• Advanced magnetic resonance (MR) imaging sequences, including fat saturation, chemical shift, and gradient-echo imaging, were crucial in detecting scant fat within the cyst.

Implications:

• The case underscores the importance of considering rare presentations of ovarian dermoid cysts, particularly lipid-poor variants.
• Advanced MR imaging techniques are vital for accurate diagnosis when typical fat content is absent.
• Early and accurate diagnosis is crucial for managing complications like chemical peritonitis and preventing misdiagnosis.