Greater trochanteric pain syndrome includes a complex differential diagnosis. We report the case of a 71-year-old woman who consulted us because of pain in the lateral aspect of the hip. A diagnosis of greater trochanter bursitis was suggested, and she was treated with local injections of a mixture of corticosteroids plus anesthetic, but the condition did not improve. A pelvic MRI showed a high intensity signal in the gluteus medius and minimus and a subsequent biopsy revealed a metastasis of an adenocarcinoma of unknown origin. Although pain on the lateral aspect of the hip is often attributed to trochanteric bursitis, other diagnoses, including this rare finding of malignant disease, should be considered in the differential diagnosis of the greater trochanteric pain syndrome.