Thyroid cancer necrosis not evident on imaging: A cautionary case series on poorly differentiated thyroid carcinoma diagnosed only on final pathology.

OBJECTIVE: Poorly-differentiated thyroid cancer (PDTC) is a highly aggressive malignancy which is recently defined and understudied in the radiologic literature. Necrosis is a key histopathologic criterion for the diagnosis of PDTC. We illustrate the current difficulty in accurate identification of histopathologic necrosis on preoperative imaging. METHODS: A series of seven patients with the final diagnosis of PDTC from our institution were identified. Multimodality preoperative imaging was analyzed by two head and neck radiologists. Final pathology reports were queried confirming histopathologic evidence of necrosis. RESULTS: Patients presented with a wide range of preoperative imaging features. A consistent imaging appearance confirming necrosis was not identified. All patients were subsequently upstaged to PDTC following final pathological analysis. CONCLUSION: A lack of definitive evidence of necrosis on preoperative imaging does not exclude the possibility of PDTC. We demonstrate the need for further research to establish a clear methodology for the preoperative diagnosis of PDTC.

First reported PET positive, FDG avid free flap pedicle ossification and review of the literature.

The fibular free flap (FFF) is commonly used for head and neck bony reconstruction. Ossification of the vascular pedicle has been reported but is an uncommon complication of this procedure. Ossification of the pedicle with FDG avidity has not been identified in the literature. Here we present a case of FDG avid free flap ossification seen on PET/CT imaging in a patient who developed trismus after fibular free flap reconstruction of a maxillary defect for a primary squamous cell carcinoma of the palate. The FDG avidity of the free flap ossification and trismus were both concerning for recurrent squamous cell carcinoma.