Sinonasal neuroendocrine carcinoma is not associated with distinctive CT or MR imaging features (Kanamalla et al. 2000). On CT, it may appear as a well-defined and homogeneous soft tissue mass. Bone remodeling and/or bone destruction may also be noted. Expansion of sinusal walls, rather than destruction, could be a useful indicator that the tumor is not a conventional squamous cell carcinoma. In the series of Kanamalla et al. (2000), no evidence of intra-tumoral calcification was found. A single report in the literature described partially calcified low density naso-ethmoidal neuroendocrine carcinoma with intracranial extension (Manome et al. 1990). On MR, the lesion has been described to appear hypointense on T1 images and heterogeneously hyperintense on T2. It shows minimal heterogeneous enhancement after contrast agent administration (Kanamalla et al. 2000) (Fig. 9.16).
The biological aggressiveness of undifferentiated carcinoma often results in large, rapidly growing lesions with extensive bone destruction and invasion of adjacent structures. Lesions tend to arise in the ethmoid and superior nasal cavity, as they probably derive from schneiderian epithelium or nasal ectoderm. Intracranial and intraorbital invasion are frequent. In the series of Phillips et al. (1997), the imaging features of undifferentiated carcinoma were not specific. On CT, tumor usually did not show calcifications and enhanced variably. It appeared isointense to skeletal muscles on T1, iso- to hyperintense on T2 with non-homogeneous enhancement after contrast agent administration (Fig. 9.26).
Was this article helpful?
Are you fed up with your frequent headache pain? 101 Simple Ways to Attack Your Headache BEFORE the Pain Starts Guaranteed No Pain, No Fear, Full Control Normal Life Again Headaches can stop you from doing all the things you love. Seeing friends, playing with the kids... even trying to watch your favorite television shows.