CASE REPORT   

Il Giornale Italiano di Radiologia Medica 2018 Novembre-Dicembre;5(6):773-6

DOI: 10.23736/S2283-8376.18.00146-8

Copyright © 2018 EDIZIONI MINERVA MEDICA

language: Italian

Femoral head osteolytic lesion on (18)F-FDG PET/CT in patient in treatment for lung cancer: bone metastasis or osteonecrosis?

Domiziana SANTUCCI ✉, Eliodoro FAIELLA, Giuseppina PACELLA, Carlo ALTOMARE, Rosario GRASSO, Bruno BEOMONTE ZOBEL

Sezione di Radiologia Interventistica, Dipartimento di Radiologia, Università Campus Bio-Medico, Roma, Italia

Seventy-one year-old woman underwent upper right lobectomy in November 2016, for lung cancer accidentally diagnosed, associated with pre- and postoperative chemotherapy. The therapy was subsequently shifted to immunotherapy for development of major allergic skin erythematous reaction treated with topical, at first, and systemic, subsequently, corticosteroid therapy. At the follow-up PET/CT scan with 18F-fluorodeoxyglucose (FDG), a focal FDG uptake at focal osteolytic lesion of the left femoral head is shown. The lesion was also confirmed at X-Ray, where a focal lytic area, delimitated by a thin sclerotic margin, was documented. At this point, a magnetic resonance imaging (MRI) is performed for secondarism suspicion. The exam confirms hypointense subchondral lesion in T1-weighted images and the presence of typical “double line sign” in T2-weighted images, images highly suggestive of osteonecrosis. The lesion was confirmed as osteonecrosis at the definitive histological examination after surgery. Our case shows how femoral head osteonecrosis can show focal FDG uptake, mimicking a secondary lesion in a patient with cancer. The hip is the most common localization of osteonecrosis and it is important to know the causes of this pathology and consider the differential diagnosis with this pathology, especially in patients with risk factors, such as in case of combined chemotherapy and cortisone treatment.

KEY WORDS: Femur head necrosis - Neoplasm metastasis - Bone and bones - Fluorodeoxyglucose F18 - Positron emission tomography computed tomography