CT findings of sinonasal respiratory epithelial adenomatoid hamartoma: a closer look at the olfactory clefts.

BACKGROUND AND PURPOSE Respiratory epithelial adenomatoid hamartoma is a benign glandular neoplasm of the sinonasal cavities, which presents in isolation (REAHi) or in the setting of an adjacent inflammatory process such as sinonasal polyps. It is frequently found in the olfactory clefts. CT features of the 2 clinical presentations have not been well defined. We present the CT findings of REAH, focusing on the degree of associated sinusitis and changes in the OCs. We hypothesized that widening of the OCs and associated severity of the sinusitis are diagnostic features of REAH, differentiating it from SNP. MATERIALS AND METHODS In this case-control study, we compared patients with REAHi, those with REAH in the setting of SNP (REAHsnp), and those with SNP only (control patients). Patients with REAH were excluded if they had an adjacent inflammatory process other than SNP or if they did not have disease in the OC. We analyzed Harvard sinus CT scores and OC dimensions. RESULTS A total of 29 patients with REAH were included: 7 with REAHi and 22 with REAHsnp. A total of 26 control patients were identified. Patients with REAHi had significantly lower Harvard CT scores than did the other groups. The OC width and the ratio of OC to the total nasal distance were significantly larger in both REAH groups compared with those of the control patients. If the OC is 10 mm or more, the sensitivity and specificity for the presence of REAH are 88% and 74%, respectively. CONCLUSIONS Both clinical presentations of REAH are associated with OC widening on CT scan. In the setting of polypoid disease, an OC width of > 10 mm should increase suspicion for the presence of REAH.