. Respiratory epithelial adenomatoid hamartoma - typical but underdiagnosed pathology of nasal cavity and sinuses.

Respiratory epithelial adenomatoid hamartoma (REAH) is relatively new diagnosis, firstly described in WHO tumour classification in 2005. It is a benign lesion affecting nose and paranasal sinuses. Although REAH was considered a rare entity, it is recently more frequently revealed in histopathological exam in patients undergoing endoscopic surgery for nasal polyposis. There have been so far operated two patients with diagnosis of REAH in our department. Both were solitary lesions, and both were resected endoscopically. Definitive histopathological examination confirmed the finding of preoperative biopsy under local anesthesia. No recurrent disease has been observed. Considering quite frequent occurrence of REAH in patients with nasal polyposis and low awareness of the disease itself among ENT specialists, pathologists and radiologists it is still relatively underdiagnosed lesion. The possibility of misdiagnosis and confusion with other more serious diseases like inverted papilloma or low-grade adenocarcinoma is of clinical importance. It may lead to overtreatment and too aggressive surgical therapy.