Ameloblastoma - Management and Review of Literature
J.A. Mallick,S.A. Ali ( Ziauddin Cancer Hospital, Medical University, Karachi. )
Case report of a 71 year old male with a history of ameloblastoma who came to us with recurrence. The
case has been reviewed in the light of recent literature available on the subject related to the
management of recurrent ameloblastoma.
Case Report
A 71 year old male with a history of ameloblastoma, presented with a complaint of swelling,
dislocation and pain on the right side of the face; and on the right mandibular region. The patient had
already been diagnosed as ameloblastoma in August 2000. Initial histopathology report revealed
ameloblastoma (border line malignancy). Subsequently he underwent surgery. Unfortunately adequate
radical resection was not done. However, he exhibited recurrence and came to our clinic in January
2002.
On examination, swelling on the right side of the face measured 5.0 cms approximately, extending up
to right periorbital region with marked deviation of the jaw towards the right side. The lower extension
could not be assessed. Right anterior cervical lymphadenopathy was also noted.
CT scan of face and neck showed a destructive lesion arising from right side of the angle of mandible,
extending into para-pharyngeal space to infracrinal space causing erosion of the base of skull and
petrous temporal bone, reaching into cranial cavity. No evidence of brain parenchymal involvement
was noted. Right side cervical lymphadenopathy was also present.
He denied any significant past medical history. His base line investigations including blood counts,
blood chemistry, Electriocardiogram, chest radiograph and U/S whole abdomen were normal. Palliative
radiotherapy was planned: 5000cGy in twenty five fractions, five days a week, with right and left
lateral fields, size of 9X10cms respectively with separation of l3cms; which included base of skull,
orbit and upper part of neck with shielding to cornea and lens.The patient died due to his progressive
disease as he himself refused to undergo the prescribed treatment.
Discussion
Ameloblastoma is the most common odontogenic neoplasm. Amelobiastoma, a locally aggressive jaw
tumor with high propensity for recurrence is believed to arise from the remnants of odontogenic
epithelium, lining of odontogenic cysts and basal layer of overlaying mucosa1. In contrast to squamous
cell carcinoma of head and neck, which are relatively common these tumors are rare but have tendency
to recur, This disease accounts for 1% of all tumors of the maxilla and mandible; and 11% of all
odontogenic tumors2. The susceptible age is from 20 - 50 years3-5. Male-female distribution is equal.
Eighty percent of ameloblastoma occurs in the ramus of mandible6-8. The remaining twenty percent
occurs in maxilla 9. Ameloblastoma are non-capsulated tumors. Histologically there are two basic
patterns, Follicular and Plexiform. In both patterns the stroma is composed of mature fibrous
connective tissue; however, the follicular contains island of epithelium within the stroma and plexiform
contains cords of epithelium within the stroma9.
Ameloblastoma are classified in four groups; unicystic, solid or multicystic, peripherial and malignant.
The unicystic ameloblastoma is essentially a 'cystic' lesion with either an intramural or an intraluminal
proliferation10. Histologically it has three significant features: 1) Columnar cells resembling
ameloblasts occupying the basal layer; 2) Hyperchromatic nuclei having a vacuolated atypical
cytoplasm and 3) Loose stellate reticulum-like epithelium. Usually they are less aggressive than solid
ameloblastoma10. The multicystic ameloblastoma can grow to an enormous size. It can infiltrate into
adjacent structures and has ability to recur and metastasize. Multicystic ameloblastoma has a poorer
prognosis than cystic ameloblastoma11.
The peripheral ameloblastoma occurs in the alveolar mucosa; however, the underlying bone can be
involved due to secondary erosion12. This type of ameloblastoma is rare. The malignant ameloblastoma
is also rare. Elzay and Corio et al, defined this lesion as an ameloblastoma that has metastasized but
still maintains its classical microscopic features13,14.
Radiology and location are key factors to diagnose ameloblastoma correctly. Plain radiograph,
panoramic radiograph, computed tomography (CT) and magnetic resonance imaging (MRI) are used as
diagnostic tools. Findings may include expansion of cortical plate with scalloped margins,
multiloculations or soap bubbl& appearance with root resorptions. CTs are used to delineate soft tissue
lesion, erosion of bone and extension of tumor into adjacent structures, MRIs are not useful for hard
lesions, but are used to detect the edges and consistency of the tumor15.
Ameloblastoma is the locally benign invasive tumor, with tendency to recur, metastasize and undergo
malignant transformation. Recurrence seems to depend on several factors such as method of treatment
of primary lesion, extent of lesion and the site of origin16. Recurrence rates also vary for different
procedures used to treat primary lesion, Several authors have found a recurrence rate 55 to 90% for all
ameloblastomas treated with conservatively (enucleation and curettage). However, the incidence of
recurrence following radical resection is 5 to 15%16,17.
Surgery is the treatment of choice for ameloblastomas. Treatment ranges from conservative surgery to
radical procedures, which include radiotherapy, curettage and enucleation. Surgery includes, removal of
at least 1cm of normal bone beyond the tumor margins18,19. Soft tissue borders at the time of resection
may also be confirmed by frozen sections to ensure complete removal of the tumor11.
Radiotherapy is rarely used as primary treatment, Some authors believe that radiotherapy should only
be used for inoperable cases20. Other investigators advocate that radiotherapy in conjunction with
surgery may have a place in the management of selected patients with recurrence. When first excision
is inadequate and soft tissue is involved or positive surgical margins observed, a total dose of
radiotherapy 5000 cGy postoperatively should be given21.
This case report emphasizes on the importance of complete surgical resection. As ameloblastoma has
high tendency to recur, all possible efforts must be taken to evaluate the extent of the tumor to adjacent
structures before surgery, to avoid recurrence or metastasis in future. Ameloblastoma may recur even
after fifteen years or more18. Therefore, it is important to keep the patient under long term follow-up.
References
1.Shafer WG, Hine MK, Levy BM. Odontogenic tumors. In a Textbook of oral pathology. 4th edition.
Philadelphia: WB Sanders Co. 1983: 258-3 17.
2.Gorlin RJ, Chaudry AP, Pindborg JJ.Odontogenic tumors: classification, histopathology and clinical
behavior in man and domesticated animals. Cancer, 1961; 14:73-101.
3.Regez JA, Kerr DAOdotogenic tumors: analysis of 706 cases. J. Oral Surg., 1978; 36:771.
4.Small IA, Waldron CA. Aineloblastoma of the jaws. J. Oral Surg.,.1955; 8:281-97.
5.Mehlisch DR, Dahlin DC, Masson JK. Ameloblastoma: a clinicopathologic report. J. Oral Surg.,1972
30:9-22.
6.Gardener DG. Plexiform unicystic ameloblastoma a diagnostic problem in dentigerous cysts. Cancer,
1981; 47: 1358-62.
7.Gardener DG, Corio RL. Plexiform unicystic ameloblastomas: a variant of ameloblastoma with low
recurrence after enucleation. Cancer, 1984; 53:1730.
8.Ackerman GL, Altini M, Shear M. The uncystic ameloblastoma: a clinicopathologic study of 57
cases. J. Oral Pathol., 1988;17:541.
9.Appel BN, verbin RS. Odontogenic tumors. In: Barnes EL, ed. Surgical pathology of head and neck.
New York: Marcel Dekker, 1985, pp. 133 1-1409.
10.Robinson L, Martinez MG. Unicystic ameloblastoma: a prognostically distinct entity. Cancer, 1977;
40:2278-82.
11.Williams TP. Management of ameloblastoma: a changing prospective. J Oral Maxillofac Surg.,l 993;
51:1064-70.
12.Stanley HR. Krogh HW. Peripherial ameloblastoma: report of case. Oral Surg., 1959; 12:760.
13.Elzay RP. Primary intraosseous carcinoma of the jaws review and update of odontogenic carcinoma.
Oral Surg:1982;54:299.
14.Corio RL, Gold blatt LI, Edwards PA, et al. Ameloblastoma carcinoma: a clinicopathologic study
and assessment of eight cases. Oral Surg., 1987; 64:570.
15.Minami M, Kaneda T. Ameloblastoma in the maxillomandibular region: MR imaging. Radiology, 1
992;1 84: 389-93.
16.Dolan EA, Angelillo JC, Georgiade NG. Recurrent ameloblastoma in autogenous rib graft. Oral
Surg., 1981; 51:357-360.
17.Muller H, Slootroeg PJ. The growth characteristics of multilocular ameloblastoma. J. Maxillofac
Surg., 1985;13:224-230.
18.Gardner DO, Pecak AMJ. The treatment of ameloblastoma based on pathologic and anatomic
principles. Cancer, 1980; 46:25 14 -19.
19.Muller H, Slootweg PJ. The ameloblastoma: the controversial approach to therapy. 3. Maxillofae
Surg., 1985: 13:79.
20.Miyamoto CT, Brendy LW, Markoe A, et al. Ameloblastoma of the jaw: treatment with radiation
therapy and case report. Am. J. Clin. Oncol., 1091 ;14:225-30.
21.Pinsolle J, Michelet V. Treatment of ameloblastoma of the jaws. Arch. Otolaryngol. Head and Neck
Surg., 1995; 121: 994 - 96.
