Occult breast primary malignancy presenting as isolated axillary lymph node metastasis - early detection of primary site by 18F-FDG PET/CT.

Breast cancer patients rarely present with isolated axillary lymph node metastasis without any clinical or radiological evidence of primary tumor. Identification of the primary site of tumor helps in planning appropriate patient management which has definite impact on patient's survival. We present here a case of 30-year-old female who presented with isolated right axillary lymph node metastasis with no evidence of primary tumor clinically. Conventional imaging modalities were negative for primary site. She underwent whole body 18F-Flurodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and it contributed significantly in early detection of occult primary tumor in right breast.