This 36-year old female presented with bilateral ingulnal adenopathy and a subsequent right groin biopsy demonstrated a non-Hodgkin's lymphoma. CT scans of the chest, abdomen and pelvis showed retroperitoneal and inguinal adenopathy. Based upon the patient's physical examination and CT scan results, the patient had stage II lymphoma. The patient was referred for a PET scan to assess the extent of the disease.

Extensive hypermetabolic abnormalities are seen in the retroperitoneal, pelvic and inguinal nodal areas. PET also demonstrates mediastinal, supraclavicular and cervical disease not shown by CT. The normal-sized spleen (see arrow) is diffusely involved. These abnormalities are compatible with lymphoma.

Based on PET results, the patient was restaged as IIIs. Due to the extent and bulk of the disease, the patient underwent an aggressive chemotherapy regime. In this patient, PET scanning resulted in a more accurate assessment of disease extent. She was upstaged from stage II to stage IIIs and her therapy was altered.

PET evaluation of lymphoma typically results in staging changes in nearly 25% of patients.