Adenoid ameloblastoma: clinicopathologic description of five cases and systematic review of the current knowledge

Adenoid Ameloblastoma with Dentinoid

“…Perhaps, many cases of AAD might be overlooked by pathologists as AM or AOT depending on the predominance of either entity in the microscopic examination. This possibility is supported by the fact that 4/45 cases of AM were re-assessed and re-classified as AAD in a retrospective study by Loyola et al [13]. Therefore, the actual number of cases might be much greater than those reported in the literature.…”

“…Adorno-Farias et al demonstrated pseudoducts with PAS-positive material [24]. Loyola et al [13] stated that although basophilic mucoid material may be observed within the duct-like spaces, secretory component was not detected. In the most recent case of AAD reported by Arruda et al, Alcian blue staining revealed a significant amount of basophilic material and scarce PAS-positive eosinophilic material in duct-like spaces, indicating its mucoid nature [25].…”

“…The radiographic evaluation revealed that the lesion presented as a well-defined unilocular radiolucency (n = 20) which was similar to that commonly noted in AOT. Loyola et al (2015) reported only two cases presented a poorly defined radiolucent lesion, which occurred in the maxillary jaw involving the nasal fossa, nasal and paranasal sinuses, and the orbit [13]. In cases of large AM or AOT, similar involvement of nasal and maxillary sinuses with poorly defined lesions has been reported [27].…”

“…Strong and diffuse positive immunostaining for CK19 staining was observed in 12/15 cases of AAD. CK19 is homogenously expressed in the stellate reticulum-like cells, peripheral preameloblast-like cells, areas of squamous metaplasia, some cells of the adenoid structures, and areas with whorled appearance [11,13,24]. It has been hypothesized that CK19 characterizes ameloblasts and preameloblasts with complete differentiation.…”

Update on Odontogenic Tumors: Proceedings of the North American Head and Neck Pathology Society

“…In 2015, a more recent article by Loyola et al brought adenoid ameloblastoma to the forefront presenting 5 additional cases and, to date, less than 40 cases have been reported with numerous reports occurring in the last five years [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. Given the small number of cases, it is difficult to draw conclusions, but these tumors appear to present in a wide age range (19-79, mean 43 years), as large tumors with a mean size of 4.4 cm, with a maxillary predilection (67%), and have a relatively high recurrence rate (10/13, 77%) [28,[32][33][34][35][36][37][38][39][40][41][42]. The histologic features include a cribriform architecture with duct-like structures, peripheral columnar cells with reverse polarity, clear cells, ghost cells (that may calcify), variable amounts of dentinoid/ osteoid, increased mitotic activity, pseudopapillary areas, and distinctive whorls/morules ( Fig.…”