Sinonasal ameloblastic carcinoma in a 48-year-old Filipino male: A rare fortuity

ABSTRACT

OBJECTIVE@#To report a case of sinonasal ameloblastic carcinoma in a 48-year-old Filipino male & discuss its clinical manifestations, diagnosis, histopathology and possible treatment options.@*METHODS@#Design: Case Report, Setting: Tertiary Government Hospital, Patient One@*RESULTS@#A 48-year-old Filipino male consulted at our OPD due to progressive right- sided nasal obstruction, rhinorrhea, hyposmia & intermittent controlled episodes of epistaxis for one year. On anterior & posterior rhinoscopy, a fleshy, soft tissue mass is seen in the nasal floor. On further examination with rigid nasal endoscopy, the same pink, fleshy, soft tissue mass was seen occupying entirely the right nasal floor with nasopharynx hardly to be visualized, and friable upon insinuation. A preoperative punch biopsy of the mass was done at our OPD revealing histologic features consistent with ameloblastoma. Contrast-enchanced computed tomography (CT) scan of the paranasal sinuses revealed a prominent soft tissue density mass lesion filling right sinonasal cavity. It is further noted the heterogenous characteristic of an isodense mass in the right nasal cavity enhancing from the nasopharyngeal area, with complete obstruction of the osteomeatal unit (OMU) and some lytic changes on the medial maxillary sinus wall however no bony changes noted on bilateral orbital floor and skull base. The mass was completely excised by medial maxillectomy via midfacial degloving. Final histopathologic studies showed islands of lace-like areas and nests of atypical odontogenic cells with central stellate reticulum, palisading columnar cells exhibiting reverse polarity and moderate mitotic activity with atypical mitotic figures present on two specimens labelled as "posterior nasal septal mass" & "nasopharyngeal mass".@*CONCLUSION@#Ameloblastic carcinoma is an uncommon entity of malignant odontogenic tumors that may originate de nova or from a benign ameloblastoma which exhibits malignant histologic features in the primary lesion and/or distant metastasis. On the other hand, malignant ameloblastoma exhibit benign histologic fea tures both for the primary and distant metastasis. This report depicted an uncommon case of ameloblastic carcinoma found extragnathically, that is in the sinonasal region. This is the second case of ameloblastic carcinoma of the sinonasal region documented in the Philippines. This case report might be a step on the ladder to generate more information regarding the biologic behavior of this entity and might ignite the enthusiasm in performing more evidence-based studies needed for its treatment as well as for its surveillance. Wide surgical resection, which is the treatment of choice, can pose challenge to otolaryngologist in the case of sinonasal ameloblastic carcinoma due to the surrounding vital structures present. Role of chemotherapy and radiotherapy is as yet conclusive due to very limited evidence- based studies available.