Isolated avulsion fractures of the pelvic ring are rare and occur predominantly in adolescent athletes. Isolated fractures of the lesser trochanter are reported to be pathognomic for tumor diseases in adults. We present a case of a female patient with an isolated avulsion of the lesser trochanter after treatment by her chiropractor. After staging examination, we determine the diagnosis of a left-sided carcinoma of the mamma. Additional imaging shows multiple metastases in liver, spine and pelvis. Palliative therapy has started over the course of time. We suggest, on suspicion of a malignant metastatic process, further investigation.