cT4bN0 small cell neuroendocrine carcinoma of nasopharynx/sinus with extension to the skull base, who received cisplatin/etoposide and concurrent radiation. FACE: There are post-treatment findings in the nasopharyngeal and sinonasal regions with a defect in the exosurface of the clivus, which demonstrates diffuse enhancement, as well as prominent mucosal thickening in the bilateral maxillary sinuses and to a lesser extent in the anterior ethmoid cavity. There is diffuse hyperenhancement of the nasopharyngeal mucosal space, but no evidence of discrete mass lesions or significant cervical lymphadenopathy based on size criteria. There is a wide left mandibular molar extraction cavity containing probable granulation tissue. BRAIN: There is a new enhancing nodular lesion in the left inferior colliculus that measures up to 7 mm. There is also new diffuse thickening and hyperenhancement of the pituitary infundibulum, measuring up to 5 mm in diameter. In addition, there is abnormal diffuse leptomeningeal enhancement along the superior cerebellum in the region of the midline and along the bilateral Sylvian fissures and anterior temporal poles, as well as perhaps along the inferior brainstem and cervical spine cord. There is no evidence of intracranial hemorrhage or acute infarct. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact.
1. Post-treatment findings in the nasopharyngeal and sinonasal regions without evidence of measurable mass lesions in the treatment bed. 2. Interval appearance of a subcentimeter enhancing nodular lesion in the left posterior midbrain, thickening and hyperenhancement of the pituitary infundibulum, and leptomeningeal enhancement along at least the superior cerebellum in the region of the midline, bilateral Sylvian fissures, and anterior temporal poles. Differential considerations include metastatic disease with leptomeningeal carcinomatosis versus an inflammatory process such as sarcoidosis, for example.