Mandibular ameloblastoma and maxillary adenoid cystic carcinoma: case report - Original Article

Ear, Nose & Throat Journal, Dec, 2003 by Tiia Tamme, Edvitar Leibur, Andres Kulla

Abstract

We report the case of a 74-year-old woman who developed a follicular ameloblastoma of the right mandible and 22 months later developed a cribriform adenoid cystic carcinoma of the soft palate on the right maxilla. The ameloblastoma was treated by hemimandibulectomy, and the adenoid cystic carcinoma was managed by resection of the soft palate and the surrounding tissue and bone followed by a 6-week course of radiotherapy. Our review of the literature indicates that only one similar case has been previously reported where an odontogenic tumor and a salivary, gland tumor involved two different anatomic locations in the same patient at nearly the same time.

Introduction

Ameloblastoma is the most common odontogenic tumor of epithelial origin, and its manifestations are part of a large spectrum of atypical clinical and pathologic findings. As a result, ameloblastoma continues to be a subject of intense interest and controversy, even after more than 100 years of recorded observation. (1) Ameloblastoma of the jaw is a relatively rare phenomenon, accounting for 1% of all tumors and cysts in the head and neck region and 11% of all odontogenic tumors.(2-4) Ameloblastoma can occur anywhere in the mandible or maxilla, although the mandibular molar area and the area around the ascending ramus appear to be the most common sites, (5,6) Ameloblastoma is usually a benign, locally infiltrative tumor, although it can undergo malignant transformation and metastasize. There appears to be general agreement that ameloblastomas are radioresistant, although some investigators regard them as radiosensitive. (4,5)

Ameloblastomas are divided into two biologic-microscopic subtypes: polycystic and unicystic. Both subtypes usually occur in the body of the mandible and in its ascending ramus. Unicystic ameloblastoma is generally associated with a lower rate of postoperative recurrence than is the polycystic form. Several bistologic patterns of ameloblastoma have been described. The most common microscopic subtype is the follicular pattern. (1,3,5) Two of the other subtypes are plexiform and acanthomatous. Some authors have suggested that the tumor subtype may be indicative of its future biologic behavior. (5,6)

Adenoid cystic carcinoma is a rare malignant tumor that affects the major and minor salivary glands, the lacrimal glands, the ceruminous glands, and occasionally the excretory glands of the female genital tract. (7) It accounts for approximately 10 to 15% of all head and neck tumors. (8) Approximately 50 to 70% of reported cases occur in the minor salivary glands. (3) The most common location is the palate, generally in the area of the greater palatine foramen. Adenoid cystic carcinoma is a radiosensitive tumor that is well known for its prolonged clinical course and its tendency for delayed distant metastasis. (3,7) Several histologic growth patterns have been described, including the cribriform or cylindromatous pattern, the tubular-trabecular pattern, and the solid basaloid pattern; in some cases, a combination of patterns is seen. (3)

In this article, we describe an unusual case of ameloblastoma of the mandible and adenoid cystic carcinoma of the soft palate covering the maxilla that occurred in the same patient at almost the same time. To our knowledge, only one similar case has heretofore been published. (9) We also provide a brief discussion of these two tumors based on the relevant literature.

Case report

A 74-year-old woman complained of a slowly growing, painless mass in the right mandible of 5 months' duration. On clinical examination, the mass was firm. The oral examination revealed firm swelling in the area of a missing molar and the dextrolateral pharynx. A panoramic x-ray examination revealed multilocular radiolucency in the ramus ascendens and the angulus mandibula on the right (figure 1).

[FIGURE 1 OMITTED]

With the patient under local anesthesia, an incisional biopsy was performed. The tissue was submitted for microscopic examination, and an ameloblastoma of the follicular type was diagnosed. The tumor was removed via block resection of the right mandible with exarticulation. An AO plate was inserted. On macroscopic examination, the resected specimen appeared as a soft-tissue mass attached to a segment of the mandible. A portion of the mandible had been destroyed and partly replaced by an ulcerating and partially encapsulated mass. The condyle of the temporomandibular joint was completely destroyed. The tumor margins were well defined. The specimen submitted to microscopic examination was found to include some tiny lymph nodes (figure 2). Operative biopsy confirmed that the tumor was an ameloblastoma of the follicular type (figure 3).

[FIGURES 2-3 OMITTED]

Some 22 months after the hemimandibulectomy, the patient noticed a painless mass in her soft palate. Preoperative histopathology indicated that it was an adenoid cystic carcinoma with a cribriform pattern. No evidence of bone involvement was seen on panoramic x-ray and computed tomography (CT), nor was there any clinical or radiologic evidence of cervical lymphatic metastasis. The tumor was removed by resection with wide margins of surrounding normal tissue and underlying bone. Histopathologic examination identified the tumor as an adenoid cystic carcinoma that featured both cribriform and tubular-trabecular patterns (figure 4). Findings on chest x-ray were normal. The patient was then treated with radiotherapy. Over a 6-week period, a total of 75 Gy was applied to the right maxillofacial region.