Presentation
Chronic right pelvic pain in a cattle breeder. Chest radiograph and upper abdominal ultrasound were normal.
Patient Data
There is a large multiloculated lobulated cystic mass (13.5 x 9 x 8.5 cm) of the right half of the bony pelvis, composed of numerous cysts of various size. It involves mainly the iliac wing, acetabular roof, superior/inferior rami, and ischial tuberosity. It elicits an iso-to low signal as compared to the muscles on T1, high T2/STIR with a thin peripheral rim of enhancement on postcontrast sequences. There is an extension to the adjacent soft tissues mainly the obturator internus/externus muscles as well as the right sacroiliac joint.
Case Discussion
The MRI features of multivesicular cystic mass of the right half of the bony pelvis extending to the adjacent soft tissues in a cattle breeder are highly suggestive of a hydatid cyst.
Musculoskeletal hydatid infections are a very rare form of hydatid disease. Patients usually present with slow-growing swelling with or without pain. They can present almost anywhere, but most common locations are vertebrae/para-vertebral soft tissue, pelvis, femur and soft tissue of lower limb.
Additional contributor; C. Boukaaba, MD