Unicystic ameloblastoma with impacted third molar mimicking dentigerous cyst

Abstract

Unicystic ameloblastoma (UA) derived the name by its macro and microscopic appearance. It is considered to be less aggressive compared with conventional ameloblastoma both in its growth pattern and recurrence rate, however, few of its histopathological types are treated in the same manner as that of conventional ameloblastoma. Therefore, the aggressiveness of this lesion is a dependent factor. Most of these lesions when occur in the mandibular third molar region with impaction, they are usually removed on radiographic diagnosis of dentigerous cyst and then the specimen is subjected to histopathological examination. Hence, the diagnosis of UA is evident only after microscopic evaluation of the specimen. Here, we report one such case of UA treated by enucleating on radiological findings. Clinical Relevance to Interdisciplinary Dentistry When a cyst of the jaw is associated with impacted tooth the most common provisional diagnosis is dentigerous cyst, at the same time unicystic ameloblastoma (UA) (dentigerous variant) need to be considered as one of the differential diagnosis along with other cysts of the jaws. Then, it becomes important for the radiologist to carefully examine radiograph to assess the true dentigerous cyst-impacted tooth relationship to narrow down the diagnosis On removal of such cyst either in toto or as a cyst wall curettage, it is important for the surgeon and the pathologist to examine both the inner and outer wall of the cyst sac. The presence of several polypoid/exophytic/nodular growths in the inner and/outer surface of the cyst wall may favor the initial diagnosis of UA rather than dentigerous cyst even though lack of these finding does not contradict the diagnosis of UA When treatment of such cyst done based on radiographic diagnosis, entire tissue of the cyst after enucleation must be evaluated histopathologically by the pathologist to eliminate possibility of UA and when diagnosed histopathologically as UA, serial sectioning of the entire tissue is mandatory for the pathologist to arrive at the diagnosis of proper subtype of UA, as the recurrence rate changes accordingly In our case, the UA was treated conservatively by considering the radiographic diagnosis of a dentigerous cyst. Whereas histopathology revealed UA subtype 1.2.3. Follow-up after 6 months showed good bone remodeling with no sign of recurrence on the radiograph. Since the recurrence of UA is long delayed, regular follow-up for a long period is necessary Thus, the collective opinion by the clinician, radiologist, surgeon, and pathologist plays a very important role in the effective management of UAs.