CLINICAL CASE

A 71-year-old agricultural worker who had stopped smoking 20 years ago (two packets of blonde cigarettes/day) and reported moderate alcohol consumption presented without known allergies and with a history of arterial hypertension subjected to treatment with antihypertensive drugs. Two years before he had been diagnosed with colon adenocarcinoma located in the rectum-sigmoid region and subjected to left hemicolectomy. He was referred to our Service with a tumor in the lower left alveolar margin that had been present for the previous 30 days, and which according to the patient started as an ulceration.

The extraoral examination revealed no asymmetries or swellings, and no adenopathies were palpated. The intraoral evaluation showed a tumor located in the left-side mandibular gums, extending to the floor of the mouth and measuring about 3 cm in size. The lesion showed surface ulceration and was of a soft consistency. As complementary tests, an orthopantomographic study was requested, together with computed tomography (CT) and a biopsy.

Orthopantomography revealed a poorly defined radiotransparency in the region of the left mandible. CT in turn confirmed the presence of a poorly delimited lytic lesion in axial and coronal acquisitions, with erosion of the mandibular cortical layers. The histological study diagnosed poorly differentiated adenocarcinoma. Considering the antecedents of the patient, the rapid evolution of the tumor, the important bone involvement and the histological diagnosis, we concluded that the lesion could correspond to colon adenocarcinoma metastasis. The patient died a few weeks later as a result of rapid worsening of his general condition, secondary to dissemination of the malignant disease.

 

DISCUSSION

Metastases to the oral cavity are very infrequent, with percentages in the range of 1% in both soft tissues and maxillary bone. Most such lesions are located in bone (85%), particularly in the lower jaw in the premolar region, due to the increased presence in this zone of bone marrow – and hence of vascularization. Clinically, these lesions manifest in the form of paresthesias or a tumor mass (1). Our patient presented a left mandibular lesion affecting both bone and soft tissues – the clinical manifestation being in the form of an exophytic, mamillated tumor that had grown over a short period of time.

Metastases of the oral cavity can present at any age, though they are more common in the 60-80 years age range. There is no predilection for either sex, and the primary tumor is fundamentally located in breast (women) or lung (males). Primary lesions of the lung, kidney and liver tend to produce soft-tissue oral metastases, while breast, prostate, bladder and colon malignancies tend to yield maxillary metastases. Adenocarcinoma is the most common histological presentation. Colon adenocarcinoma metastases to other parts of the body are relatively frequent, though metastatic spread to the oral cavity is quite unusual (2).

Tumor cell spread from the primary lesion is via the vascular route – probably through the vertebral venous system. The cells penetrate the bone through the nutrient arteries and proliferate within the bone marrow compartment - causing cortical perforation, which in turn facilitates spread to the adjacent soft tissues (3). In colon adenocarcinoma, metastatic spread occurs through the liver in a first stage and the lungs in a second phase – thus resulting in possible metastatic lesions in these organs (4). Our patient presented a poorly differentiated adenocarcinoma that had invaded both the bone and gingival tissues. We were unable to determine whether there was also lung or liver involvement, due to his rapidly deteriorating general condition.

 

The clinical differential diagnosis must be established with other reactive, inflammatory or neoplastic tumor processes such as pyogenic granuloma, fibroma, giant cell lesions, oral squamous cell carcinoma, or non-Hodgkin lymphoma, which are disorders that sometimes show rapid growth. The patient antecedents, location of the lesion, growth rate, clinical appearance and radiological findings were suggestive, though diagnostic confirmation in all cases requires histological study (5). The presence of pain, dental mobility or paresthesias is suggestive of malignancy, and if the patient moreover has a history of some primary malignancy, the possibility of metastatic spread must be considered in the differential diagnosis.

 

The X-ray study most often reveals an osteolytic lesion with poorly defined limits, though some tumors such as those located in breast, prostate gland and lung can give rise to bone lesions with a sclerotic appearance and the possible presence of osteoblastic lesions. Computed tomography, magnetic resonance imaging and gammagraphy are very useful diagnostic techniques for the assessment of disease spread within maxillary bone (6).

 

In most cases the primary lesion has already been diagnosed, though in up to one-third of patients the intraoral lesions may constitute the first expression of a previously undetected neoplastic process (1). In order to confirm that metastasis is involved, the criteria established by Clausen and Poulsen should be applied, i.e., the primary lesion must be histologically confirmed; the metastatic lesions must be histologically diagnosed; and the possibility of direct extension of the primary lesion must be discarded (7). In our case all three criteria were met, thus suggesting the existence of colon adenocarcinoma metastasis.

 

Treatment is generally palliative, due to the severity of the patient condition. Radiotherapy is usually provided, or the lesion may be subjected to surgical resection when its size causes eating or speech difficulties. This contributes to improve patient quality of life in cases characterized by soft tissue lesions – where the rapid growth sometimes makes it difficult even to close the mouth (8).

 

References

 

1.     Van der Waal RIF, Buter J, Van der Waal I. Oral metastases: report of 24 cases. British J Oral Maxillofac Surg 2003; 41: 3-6.

2.     Mason AC, Azari KK, Farkas LM, Duvvuri U, Myers EN. Metastatic adenocarcinoma of the colon presenting as a mass in the mandible. Head Neck 2005; 27: 729-32.

3.     Delfino JJ, Wilson TK, Rainero DM. Metastatic adenocarcinoma from the colon to the mandible. J Oral Maxillofac Surg 1982; 40: 188-90.

4.     Babu KG, Raud C, Kumaraswamy SV, Lalitha N. Carcinoma of the colon with mandible and liver metastases. British J Oral Maxillofac Surg 1996; 34: 133-4.

5.     Gonzalez-Martin-Moro J, Cebrian-Carretero JL, Gomez-Garcia E, of the Castillo-Pardo of Vera JL, of the Val D. Intraoral tumor with rapid growing. Report of a case. Med Oral Patol Oral Cir Bucal 2005; 10: 440-3.

6.     Sanchez-Jimenez J, Acebal-Blanco F, Arevalo-Arevalo RE, Molina-Martinez M. Metastatic tumours in upper maxillary bone of esophageal adenocarcinoma. A case report. Med Oral Patol Oral Cir Bucal 2005; 10: 252-7.

7.     Schwartz ML, Baredes S, Mignogna FV. Metastatic disease to the mandible. Laryngoscope 1988; 98: 270-3.

8.     Hirshberg A, Buchner A. Metastatic tumours to the oral region. An overview. Oral Oncol Eur J Cancer 1995; 31B: 355-60.