Hydatid disease of bone: a dangerous crippling disease.

To cite: Raj DH, Dash PK. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2015-211697 DESCRIPTION A 40-year-old man presented with severe pelvic and right hip joint pain for the past 5 years, which was insidious in onset and progressive, resulting in the patient being wheelchair-bound. He also had a history of liver surgery, which was performed 20 years prior, and for which the documentary details were lost. There was no history of fever, trauma, previous tuberculosis or bone tumours. Routine blood investigations were unremarkable. Chest X-ray was normal. X-ray of the pelvis, anteroposterior view, revealed multiple expansile lytic lesions involving the right ilium, right ischium and right pubis with involvement of the right ala of the sacrum, right hip joint, and right head and neck of the femur (figure 1). CT of the pelvis demonstrated the aforementioned findings along with extensive bone remodelling changes and disuse atrophy of the right gluteal muscles, and a three-dimensional volumetric reconstruction image of pelvic bones and femur also clearly demonstrated the findings aforementioned (figure 2). The main differentials considered were tuberculosis, osteomyelitis and osteosarcoma. We proceeded with incisional biopsy of the lesion from the right iliac bone but, to our surprise, the histopathology