Aggressive adenoid cystic carcinoma with asymptomatic spinal cord compression revealed by a "curtain sign".

The authors present a case of unusually aggressive adenoid cystic carcinoma of the head and neck. The patient presented with sciatica one year after initial diagnosis. She was otherwise asymptomatic. Complete work-up for bone involvement, included bone scan and MRI. The patient had painful osteolytic sacral metastasis and asymptomatic thoracic (T5) vertebral metastasis revealed by a typical curtain sign on MRI. The curtain sign, originally described by Trolard, is due to the displacement of the Trolard's membrane with the median ligament attaching the dura to the bone while there is a dorsal displacement and loosening of the posterior longitudinal ligament. The patient benefited from radiotherapy and did not develop respiratory distress, paraplegia or pain but died of liver metastases.

[Treatment response evaluation by functional imaging]. / Evaluation de la réponse au traitement par imagerie fonctionnelle.

Imaging in cancer plays a capital role to guide the clinician in his choice of therapies. We will discuss the new techniques available to predict and evaluate treatment response in oncology. The method of reference to evaluate treatment response is based on the measure of lesion size. Functional imaging doesn't evaluate size, but rather a physiological or molecular feature, which is probably modified earlier in response to treatment. Dynamic contrast-enhanced functional imaging of microcirculation follows the biodistribution of a contrast agent and analyses tumour vascularization. Diffusion-weighted Magnetic Resonance Imaging differentiates free and restrained water molecules in tissues, reflecting tumor cellularity. Nuclear Magnetic Resonance spectroscopy is an application of MRI that yields information on the metabolic content of a tissue. It detects relative quantities of various molecules which differ in tumour compared to normal tissue. Positon-emission tomography using (18)FDG is a nuclear medicine technique which gives information on tissue metabolism. Captation of FDG is proportional to the proliferative activity and the number of viable cells in a tumour. Human studies concerning these techniques are still quite preliminary, and the medical community must determine their potential in clinical practice to evaluate treatment response in oncology.