Sinonasal Ameloblastoma

Abstract

Ameloblastomas are benign but aggressive odontogenic tumors that most commonly affect the posterior mandible. Approximately 15% occur in the maxilla, with a subset thought to originate from the epithelial lining of the sinonasal cavities. Histologically, sinonasal ameloblastomas are identical to those of the oral cavity, with classical features of palisaded columnar basilar cells surrounding a central proliferation that resembles the stellate reticulum of a developing tooth. Unlike the gnathic variant, sinonasal ameloblastomas tend to affect males more than females, and the incidence of diagnosis peaks at a later age, approximately 60 years old. The overall prognosis is favorable, with local recurrence being the most common long-term sequalae.

Sinonasal Ameloblastoma: A Case Report and a Review of Gnathic Lesions That Occur in the Sinonasal Tract

“…5 The epithelium of SNAMs can appear continuous with the surface sinonasal tract epithelium, possibly signifying that the lesions are truly primary to the sinonasal tract. 22 Recurrent molecular findings have been identified in the mandibular and maxillary forms of AM, BRAF, and SMO, respectively, but none have been identified yet in SNAMs. 23 Immunohistochemistry can be helpful to reach a diagnosis of SNAM, especially on small biopsies; however, the immunohistochemical stains vary based on the cells present in the biopsy.…”

“…The epithelium between columnar cells is squamous and appears morphologically identical to typical stellate reticulum 5 . The epithelium of SNAMs can appear continuous with the surface sinonasal tract epithelium, possibly signifying that the lesions are truly primary to the sinonasal tract 22 . Recurrent molecular findings have been identified in the mandibular and maxillary forms of AM, BRAF , and SMO , respectively, but none have been identified yet in SNAMs 23 …”

Seltene Erkrankungen der Nase, der Nasennebenhöhlen und der vorderen Schädelbasis

“…Der Altersgipfel liegt bei ca. 60 Jahren [208] und damit etwa 15-20 Jahr höher als bei der am Kiefer lokalisierten Variante [106].…”

“…Overall, the incidence amounts to about 0.5:100 000 000 [206,207]. The age peak is at about 60 years [208] and thus about 15-20 years higher than the variation localized at the jaw [106].…”