Giant Mandibular Ameloblastoma with Rare Hypercalcemia: A Case Report and Literature Review

Abstract

Ameloblastoma is the most common benign odontogenic tumor with local invasion and high recurrence, which generally occurs in the jaw bones. Hypercalcemia is a common paraneoplastic syndrome that is commonly observed in patients with malignancies but rarely encountered in patients with benign tumors. Thus far, not many cases of ameloblastoma with hypercalcemia have been reported, and the pathogenic mechanism has not been studied in depth. This paper presents a case report of a 26-year-old male diagnosed with giant ameloblastoma of the mandible, accompanied by rare hypercalcemia. Additionally, a review of the relevant literature is conducted. This patient initially underwent marsupialization, yet this treatment was not effective, which indicated that the selection of the appropriate operation is of prime importance for improving the prognosis of patients with ameloblastoma. The tumor not only failed to shrink but gradually increased in size, accompanied by multiple complications including hypercalcemia, renal dysfunction, anemia, and cachexia. Due to the contradiction between the necessity of tumor resection and the patient's poor systemic condition, we implemented a multi-disciplinary team (MDT) meeting to better evaluate this patient's condition and design an individualized treatment strategy. The patient subsequently received a variety of interventions to improve the general conditions until he could tolerate surgery, and finally underwent the successful resection of giant ameloblastoma and reconstruction with vascularized fibular flap. No tumor recurrence or distance metastasis was observed during 5 years of follow-up. Additionally, the absence of hypercalcemia recurrence was also noted.

Keywords: ameloblastoma; hypercalcemia; marsupialization; multi-disciplinary teams; renal impairment; surgery.

Figure 1

CBCT imaging (A) and three-dimensional reconstruction of the skull (B) demonstrated extensive bony destruction and soft tissue involvement by the right mandibular tumor.

Figure 2

Right mandibular ameloblastoma resulted in huge swelling of mandible and significant facial asymmetry (A,B). Intraoral examination showed that the right buccal vestibule and gums presented widely swollen with a cauliflower-like mass (C).

Figure 3

Panoramic radiography (A), CT (B), three-dimensional reconstruction (C), and MRI (D) showed an expansive growth pattern of the tumor with bony destruction and huge soft tissue mass.

Figure 4

The change in total serum calcium levels, serum creatinine levels, and hemoglobin levels after interventions.

Figure 5

The computerized tomography with angiography of the neck vessels suggested that the right mandibular ameloblastoma was supplied by multiple branches of the right external carotid artery.

Figure 6

Gross appearance of the ameloblastoma after surgical excision (A,B). Histological biopsy of the resected specimen showed the ameloblastoma was a mainly plexiform type (C) with a small amount of follicular structure (D).

Figure 7

The patient’s facial deformity had improved greatly after tumor resection. (A–C) Clinical photos and (D,E) three-dimensional reconstruction.

Figure 8

The patient received mandibular defect reconstruction with vascularized fibular myocutaneous flap. (A) Surgical photograph. (B) Clinical photograph. (C) Panoramic radiography. (D) Three-dimensional reconstruction.