Case of Unrecognised of Maxillary Adenoid Cystic Carcinoma

Abstract

Adenoid cystic carcinoma is a less commonly diagnosed cancer that may affect the major or minor salivary glands. We present a 70 year old male patient who was admitted to the Department of Oral Medicine, School of Dental Medicine in Zagreb, Croatia due to pain in the right maxilla. In this case we report a case of the patient with unilateral pain in the maxilla & eye which lead to the diagnosis of adenoid cystic cancer without any visible oral lesions.

Introduction

Adenoid cystic carcinoma is a rare malignant tumor with an incidence rate of less than 1% of all head and neck malignancies (1). It constitutes approximately 29.6% of minor salivary gland tumors (2) and affects both males and females, without any sex predilection, and usually occurs after the fifth decade of life (3). The palate is the most common site of intra-oral lesions. In the major salivary glands, adenoid cystic carcinoma most commonly affects the parotid and submandibular glands, while palate is most frequently affected in the area of minor salivary glands, followed by the floor of the mouth, tongue and lip. In some cases it can present in the jaws as a primary intraosseous tumor (4). Characteristic signs of adenoid cystic carcinoma are slow growth pattern, tendency to local reccurrences, postponed appearance of the distal metastases as well as neural invasion (5). The most important prognostic factors include tumor size, grade, stage, lymph node involvement, neural invasion and margin status (6). Diagnosis is based on clinical examination, histopathological analysis of a biopsy specimen and imaging techniques.

In this report, we present a case where a series of unwanted circumstances arising either from the patient himself or from the specialists he visited, resulted in an inoperable maxillary adenoid cystic carcinoma.

Case report

A 70 year old male patient was admitted to the Department of Oral Medicine, School of Dental Medicine in Zagreb, Croatia in April 2017 due to pain in the right maxilla. In March 2016, he went to an ear, nose and throat (ENT) specialist due to pain in the right maxilla and a CT scan of the paranasal sinuses was obtained. Speckled zones of bone demineralization of the distant part of the right side of the hard palate were found. Since no soft tissue pathology could be seen, the patient was sent to MRI examination of the head which he never did. Our clinical examination revealed a mild assimetry of the hard palate, therefore a panoramic image was taken. It showed a mass on the right side of the maxilla and the cheek (Figure 1). Furthermore, the patient was admitted to the Emergency Ophthalmology Department due to pain in the right eye. The ophtalmologist treated the patient's glaucoma and recommended the use of ultrasound for diagnostic imaging of the eye, which the patient did not perform. Six months after the first examination at our Department, he was admitted again and tumorous thickening of the right maxilla could be noticed (Figure 2). He was immediately referred to a maxillofacial surgeon and a biopsy of palatal swelling was taken. A histopathological analysis revealed a tumor of a minor salivary gland, composed of both cribriform and tubular areas of atypical cuboidal epithelial cells with fossae of central necrosis within the cribriform areas. The final diagnosis was established. It was an adenoid cystic carcinoma (Figure 3).

Figure 1.

OPG showed a mass on the right side of the maxilla

Figure 2.

Tumorous thickening of the right maxilla which involves alveolar ridge and the hard palate extending from the region 11 to 18. Teleangiectasia can be noticed on the soft palate.

Figure 3.

Adenoid cystic carcinoma composed of both cribriform and tubular areas of atypical cuboidal epithelial cells (HEx100).

The MSCT of the head, neck, and thorax examination was performed by standard recording techniques with 3D reconstructions. On the transitions between the head and the neck in the projection of the maxillary anthrum to the right, and on the right half of the nasal cavity, a soft neoplastic heterogeneous contrast-absorbed process of about 48 mm in diameter was shown. Craniocaudal dimension of the lesion was about 70 mm with invasion into the right ortbit and the middle skull to the anterior part of the cavernous sinus. A dorsal lesion went to the right half of the sphenoidal sinus (Figure 4). On both sides of the neck, in region II, more oval lymph nodes without pathology were found.

Figure 4.

The MSCT of the head and neck. The palatal lesion extends to the soft tissue of the cheek, into the right orbit and into the anterior part of the cavernous sinus as well as into the sphenoid sinus.

Due to the size of the lesion and structures compromised, the tumor was inoperable, therefore, the patient was treated by radiotherapy. Radiation dose was 70 Gy divided at 35 fractions. After radiotherapy, the tumor has greatly reduced its size (Figure 5).

Figure 5.

Reduction of the tumor after radiotherapy.

Discussion

The differential diagnosis of aggressive intraoral lesions should, among others, consider various salivary gland tumors. In case of an aggressive lesion which involves hard palate, differential diagnoses should involve adenoid cystic carcinoma of the minor salivary glands (2). Adenoid cystic carcinoma has a slow and often insidious growth pattern and most patients present at advanced stages of the disease. Based on tumor location, patients might have different signs and symptoms. Pain is a common clinical finding due to an early perineural invasion of the neoplastic cells (7). Adenoid cystic carcinoma develops frequently in minor salivary glands in comparison to the sublingual and parotid glands. Sometimes it starts as a jaw lesion (2).

It is a well known fact that the pain arising from non-dental causes might be confused as pain arising from the tooth, which leads to misdiagnosis. Park et al., reported an adenoid cystic carcinoma of maxillary sinus misdiagnosed as chronic apical periodontitis (8),Therefore, pain associated to salivary gland malignant tumor may be misdiagnosed as pain from odontogenic origin.

In a recent study of 4004 periapical lesions which were diagnosed as endodontically associated pathoses, nine were found to be malignant processes, seven of which were squamous cell carcinoma, one Langerhans cell histiocytosis and one adenoid cystic carcinoma located in the mandible (9).

Perineural spread of the head and neck cancer was studied in a recent review (10). The results have shown that diffent types of head and neck tumors, including adenoid cystic carcinoma, can result in complications involving the afferent or efferent visual system. The authors have also reported involvement of trigeminal nerve and atypical facial pain. According to these data, a strong correlation between adenoid cystic carcinoma and pain in the ophtalmic region, as was shown in our patient, could be implicated.

A series of unwanted events made by various specialists and the patient's non compliance led to the late diagnosis of an inoperable adenoid cystic carcinoma which progressed into the skull. The patient was treated only with radiotherapy.This case report highlights the fact that although the oral cavity finding might be without any visible lesions, sharp unilateral pain might suggest underlying malignancy in the affected area as it was seen in this case.