A mass appearing within the substance of the cheek is unusual and suggests a tumor of the buccal space or the accessory lobe of the parotid gland. The buccal space, first described by Kostrubala in 1945, is a potential space between the buccinator muscle and the more superficial muscles of facial expression ( Fig. 90.1 ). There are a number of reports of buccal space masses, and many surgical approaches have been suggested in the literature. Lesions in the buccal space are readily apparent because they are easily palpated just beneath the buccal mucosa or the skin of the cheek.
Most neoplasms in the buccal space are tumors of minor salivary gland origin. Benign tumors are most often pleomorphic adenoma, monomorphic adenoma, or Warthin tumor. Malignant tumors in the buccal space include adenocarcinoma; adenoid cystic, mucoepidermoid, acinic cell, anaplastic, and small cell carcinoma; carcinoma ex pleomorphic adenoma; polymorphous low-grade adenocarcinoma; and metastasis from other sites. Other less common primary tumors include fibroma, fibrosarcoma, lipoma, lymphoma, melanoma, nerve sheath tumor, and hemangioma. For tumors other than lipoma, biopsy is necessary because no clinical or radiographic criteria are reliable in establishing a histologic diagnosis.
Key Operative Learning Points
Evaluate the patient with fine-needle aspiration biopsy and imaging before surgery to enhance planning for the surgical procedure and patient counseling.
Evaluate the patient’s needs regarding cosmetic appearance. The modified parotid incision leaves an unobtrusive but visible scar, so for a female patient, a rhytidectomy approach may be a better option, whereas the incision in a male patient is usually hidden in the beard line and is acceptable.
Undermining in the plane between the subcutaneous tissue and the superficial musculoaponeurotic system (SMAS) protects the facial nerve.
Identify the buccal and zygomatic branches of the facial nerve and dissect them off the mass.
Retract the branches of the nerve away from the mass so that it may be excised without injury to the nerve.
Closing the SMAS either primarily or with a flap will prevent an unsightly depression in the face.
History of Present Illness
The typical history encountered in patients with a mass in the buccal space is that of a slowly growing, painless mass in the cheek ( Fig. 90.2 ).
If the mass is more deeply seated, it tends to lie more medial and the patient may be able to feel the intraoral mass with the tongue ( Fig. 90.3 ).
When the mass is located in the oral cavity, patients are often seen initially by their dentist or an oral maxillofacial surgeon.
Constitutional symptoms suggest infection, an inflammatory condition, or lymphoid neoplasm.
Past Medical History
History of previous salivary gland or other neoplasms
Recent dental work or cervicofacial infections
Recent injection of facial fillers for cosmetic purposes
Use of alcohol and tobacco
Many medications may increase the likelihood of sialolithiasis.
Use of anticoagulants
A complete examination of the head and neck is warranted, as with all masses in the head and neck.
Particular attention should be given to examination of the skin for primary cutaneous malignancies and palpation for cervical metastases.
Inspection and bimanual examination usually reveals a mobile mass within the substance of the cheek that can be seen in the oral cavity (see Fig. 90.3 ).
Although facial nerve deficits are uncommon given the rich distal cross-innervation, attention to the facial nerve function is mandatory.
Basic determination of the patency of Stensen duct can be achieved by visualizing the duct orifice while milking or massaging the parotid gland from posterior to anterior.
Kurabayashi et al. evaluated the computed tomography (CT) features of masses in the buccal space in 53 patients (33 benign tumors, 11 malignancies, 9 non-neoplastic lesions) and concluded that CT was useful in demonstrating the presence and location of masses in the buccal space. CT can sometimes assist in the differential diagnosis but the value of CT in differentiating benign from malignant lesions in the buccal space is limited.
Tumors of the buccal space were found adjacent to the outer surface of the buccinator muscle in contrast to epidermoid cysts and tumors of the accessory lobe of the parotid gland, which were completely separate from it.
Tumors of the accessory lobe of the parotid gland, epidermoid cysts, lipomas, and lymphoma could be differentiated from other lesions.
Hemangiomas were characterized by multiple masses and the presence of phleboliths.
Kurabayashi et al. also studied 30 patients with benign and malignant lesions in the buccal space with magnetic resonance imaging (MRI). MRI was useful in demonstrating the extent of lesions in the buccal space, but similar to CT its diagnostic value in predicting malignancy was very limited ( Fig. 90.4 ). This was especially true for malignant tumors of minor salivary gland origin, which were typically seen as well-defined masses without infiltration into surrounding structures on MRI.
Ultrasound may be helpful in characterizing the lesion (size, echogenicity, flow, calcifications) or in assisting fine-needle aspiration biopsy.
Fine-needle aspiration biopsy is most helpful in determining the need for surgery rather than providing a definitive diagnosis.
Definitive diagnosis of a mass in the buccal space is made by excision of the mass and histopathologic evaluation.
Incisional biopsy is never appropriate, as the risks of facial nerve injury and tumor spillage are increased and postbiopsy changes may make the definitive surgery more complex.
The differential diagnosis of a mass in the buccal space includes lesions originating from each of the tissue components in the space. Table 90.1 lists the lesions that have been found in the buccal space.
Extraskeletal mesenchymal chondrosarcoma
Fibroma, fibrosarcoma, solitary fibrous tumor
Spindle cell lipoma
Accessory parotid or aberrant salivary gland tumors
Acinic cell carcinoma
Adenoid cystic carcinoma
Carcinoma ex pleomorphic adenoma
Minor salivary gland calculus
Mucoepidermoid carcinoma (low and high grades)
Papillary cystadenoma lymphomatosum
Parotid duct tumor or calculus
Polymorphous low-grade adenocarcinoma
Tuberculous granuloma and adenoid cystic carcinoma manifested as a single buccal space mass
Benign reactive lymph node
Calcified lymph node
Metastasis to lymph node
Facial fillers and injectables
Metastatic carcinoma (skin, sinus, renal cell, lung, buccal mucosa)