An ovary in luteal phase mimicking common iliac lymph node metastasis from a primary cutaneous peripheral primitive neuroectodermal tumour as revealed by 18-fluoro-2-deoxyglucose positron emission tomography

A 30-year-old female underwent surgical removal of a primary cutaneous peripheral primitive neuroectodermal tumour (PNET) of the left thigh. A subsequent 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) scan showed abnormal accumulation of FDG in the left upper pelvic region, consistent with metastasis to a left common iliac node. A series of follow-up imaging studies revealed that a cyst of the corpus luteum of ovary was responsible for the abnormal FDG accumulation.