Peroperative detection with a gamma probe of pelvic metastasis after differentiated thyroid carcinoma in female patients: about two cases and management reflections.

Background: Distant metastases of differentiated thyroid cancers are exceptionally localized in the soft tissues and the pelvic cavity. This last event complicates diagnosis, especially in female patients because of false positive nuclear imaging and unrelated iodine uptakes. False positive due to body secretions, urinary and fecal iodine retention and iodine uptake by non-thyroid tissues or ectopic thyroid tissue and bone metastasis of differentiated thyroid carcinoma.

Methods: We present two cases of metastasectomy, guided by a peroperative gamma probe and intraoperative frozen sections of the specimens. In females patients because of potentially false positive nuclear imaging and iodine uptakes unrelated to pathology, it is very difficult to identify a pelvic metastasis. Our experience of two cases underlines these pitfalls and the possibilities to avoid them: the use of 131 Iodine SPECT/CT whole body scan, peroperative gamma probe and intraoperative frozen sections of specimen.

Conclusion: Preoperative localization needs a precise 3D imaging and the surgical treatment must be guided by a peroperative gamma probe and frozen sections.