Difficulties in the diagnosis of plexiform ameloblastoma.

BACKGROUND: Plexiform ameloblastoma is a rare and benign odontogenic tumor which may reach grotesque proportions affecting over a region of lower molars. The correct diagnosis is essential to reduce this risk of local recurrences and obtain an effective treatment. CASE REPORT: A 10-year-old female patient, Caucasian, presented a complaint of painless facial asymmetry. The clinical and imaginological examinations showed an increase in volume in the left mandibular body related to radiolucent unilocular injury near the apex of the first molar, expansion of the vestibular cortical bone, and tooth root resorption ipsilaterally. The former intraosseous biopsy suggested an aneurysmal bone cyst. In reopening the previous marsupialization, a new biopsy was performed with histopathologic findings compatible with plexiform ameloblastoma associated with acute inflammation. Curettage was performed in the region associated with cryotherapy. At the last biopsy, the diagnosis of plexiform ameloblastoma was confirmed with multiple cystic formations and areas of foreign body reaction. The patient is being followed for 2 years and yet remains clinically and radiographically stable with no recurrence. DISCUSSION: This case reports the importance of selecting the correct area of biopsy of an intraosseous extended lesion to contribute to the diagnosis and treatment of plexiform ameloblastoma.