FDG PET-CT missed tibial metastasis in head and neck cancer, case report and systematic review.

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common type of cancer in the world. Metastases occur in up to 40 % of cases and bones are the second most frequent site. Metastases in extremities are uncommon with very few publications covering distal lower-limb bone metastasis.

CASE PRESENTATION: Here we report the case of a patient with HNSCC managed by induction chemotherapy, surgery and adjuvant chemo-radiotherapy. During the adjuvant treatment, the patient presented pain in the right tibia, with additional workup revealing a distal lower-limb bone metastasis which had remained undetected during the recommended standard workup for HNSCC.

DISCUSSION: Current guidelines request that FDG PET-CT is performed down to the popliteal fossae. The undetected metastasis led to overtreatment of the patient. Systematic review of the literature showed only six cases of head and neck cancer's distal lower-limb metastasis which are eligible for discussion.

CONCLUSION

Although rare, physicians should keep in mind that as recommended FDG PET-CT does not extend below the popliteal fossae, metastases could be missed and therefore lead to inappropriate treatment.