A case of a 45-year-old female visited the outpatient department of our hospital with chief complains of swelling and pain over left hip since one and a half months. Patient also complained of jerk over her left hip joint and feeling that her lower limb getting stuck while walking. On clinical examination, she complained of pain over the left hip and patient was not able to move her leg. Her pain was aggravated on movements and relieved on taking rest. There was mild swelling and tenderness over anterior joint line, there was no discoloration over the swelling and no local rise of temperature, and the swelling was hard and firm in consistency. Range of movement of left hip could not be assessed due to pain, and range of movement of knee was full and painless. There were toe movements with intact distal circulation. There was no previous history of any trauma or fall neither loss of weight or decreased appetite and no local signs of inflammation.
On X-ray (Fig. 1), there was an eccentric expansile lytic lesion in the greater trochanter of femur involving the metaphysis, neck of the femur and extending into the subtrochanteric region showing wide zone of transition which suggests aggressive nature of the lesion with non-sclerotic margins type IB/IC. There was thinned out cortex with few areas of nearly deficient cortex with no periosteal reaction. There was extension of soft tissue mass into adjacent muscle and displacing them. There is no matrix calcification, and transverse pathological fracture of the neck of femur was seen at the basi-cervical part seen. The patient came from a low-socioeconomic background and could not afford two cross-sectional imaging, so CT scan was not formed.
On MR imaging, lesion was irregular, expansile and lytic with a heterogeneously enhancing soft tissue component showing altered signal intensity in the greater trochanter of femur involving the metaphysis and neck of the femur and extending into the subtrochanteric region. Lesion measured 7.4 × 7.4 × 7 cm and appeared heterogeneously iso-hypointense on T2WI and PD FAT SAT, hypointense on T1 and heterogeneously hyperintense on STIR. The lesion showed wide a zone of transition. Lesion was causing break in cortex with the presence of a soft tissue component. Lesion was seen displacing gluteus minimus, gamellus inferior, vastus lateralis, intermedius muscles along with ischio-femoral and ilio-femoral ligaments of left side. STIR hyperintensity was noted in the muscles of all the compartments except posterior compartment of the left thigh suggestive of myofascial edema. STIR hyperintensity was noted in left acetabular fossa suggestive of reactive synovial thickening (Figs. 2 and 3).
Fine needle aspiration cytology of the lesion arising from the greater trochanter of left femur was done, it turned out to be giant cell tumor, and this is very unusual site for giant cell tumor.