CC
65 year old woman with history of oral squamous cell carcinoma with chief complaint of new painful ulcer.
HPI
A 65-year-old female presents with a recurrent oral squamous cell carcinoma (SCC). She was initially diagnosed with a cT1N0M0 SCC of the right oral tongue. This was treated with a right partial glossectomy and selective neck dissection 10 years prior. She did not have any high-risk features on pathology and was placed on a surveillance schedule. Unfortunately, she was diagnosed with a second primary SCC involving the right buccal mucosa 9 years after her initial diagnosis. She was then treated with a composite resection of the right buccal mucosa and marginal mandibulectomy. She was found to have perineural invasion but negative margins and no bone invasion. At that time, she was reconstructed with an anterolateral thigh flap and cervicofacial advancement flap. The surgery was followed by adjuvant radiation therapy. Unfortunately, within 1 year of completion of her adjuvant radiation therapy, she developed a rapidly growing recurrence in the right buccal mucosa invading through her skin and lip ( eFig. 81.1 and Fig. 81.2 ).
PMHX/PDHX/medications/allergies/SH/FH
The patient has hypertension, depression, and anxiety. She had prior head and neck surgery. She is allergic to latex. She is taking aspirin and Lexapro.
She has a 30-pack-year smoking history, which she continued after first cancer diagnosis but quit after her second primary cancer diagnosis.
She has no notable family history.
Examination
General. Thin, anxious female. She is visibly distressed because of pain.
Neck. No lymphadenopathy is appreciated. The right neck shows prior surgery and radiation effects.
Oral. There is a massive indurated and ulcerated mass arising from the right oral commissure and buccal mucosa, extending into the mandibular gingiva, retromolar trigone, and maxillary gingiva. It invades through the skin and is visible externally. On the right facial skin, there is a 5-cm × 5-cm ulcer. It is extremely tender to palpation. The patient has lip incompetence and sialorrhea ( Figs. 81.2 and 81.3 ).
Chest. The patient’s lungs are clear to auscultation. Her pectoralis major muscles are symmetric and of normal morphology and size. If a pectoralis flap is being considered as a reconstructive option, the chest should be examined to ensure that the muscle is adequately developed. Very rarely, the pectoralis major muscle can be completely absent in patients with Poland’s syndrome.
Imaging
A positron emission tomography/computed tomography (PET/CT) examination demonstrated a fluorodeoxyglucose (FDG)-avid focus corresponding to the right facial mass. No FDG avidity or lymphadenopathy was identified in the neck or other parts of the body.
Many imaging modalities are available for evaluating patients with head and neck SCC. PET/CT has the advantage of combining the ability to identify areas of high metabolic activity by PET with the anatomic detail of CT. This is often useful in patients with metastatic disease from an unknown primary, indeterminate findings on CT or magnetic resonance imaging, high risk for or suspected distant metastases, or surveillance of patients after treatment. Patients, particularly smokers, should have their chests imaged by a plain chest film, chest CT, or PET/CT to screen for distant metastases and second primary tumors.
Labs
Laboratory testing is dictated as much by the patient’s past medical history and co-morbidities as the cancer itself. At a minimum, this includes a complete blood count, metabolic panel, and a coagulation panel. Many oncologic surgeons include liver function testing as a screen for distant metastases to the liver.
Assessment
The patient was diagnosed with a very advanced local recurrence. Although she was initially diagnosed and treated for an early-stage oral SCC with recurrence-free survival period of 10 years, she developed a second primary that very quickly recurred after standard-of-care treatment. This phenomenon of the development of a second, more aggressive oral cavity primary years later has been described in the literature and justifies the role of ongoing cancer surveillance of patients beyond 5 years.
Treatment
Treatment with curative intent would involve a large resection of her facial skin, oral commissure, lips, buccal mucosa, retromolar trigone, segmental mandibulectomy, and partial maxillectomy. Reconstruction would require replacement of the right body of the mandible, soft tissue to replace the oral mucosa, obturation of the posterior maxilla, and replacement of the facial skin. This type of ablative surgery would leave a sizeable composite bone and soft tissue defect. Options to reconstruct soft tissue include microvascular free tissue transfer or regional flaps. Free tissue transfer is an essential component of the head and neck reconstructive surgeons’ armamentarium that is versatile and capable of filling large composite defects. These are discussed elsewhere.
Because of the size of the soft tissue defect involving both the oral mucosa and external skin, her mandibular defect, and her prior use of a cervicofacial advancement flap, she would either need a chimeric flap with multiple skin paddles or two separate flaps. We decided to use two flaps: an osteocutaneous fibula free flap to reconstruct the mandible and oral mucosa and a pectoralis major myocutaneous flap to reconstruct the facial skin.
Several regional flaps can be used for reconstruction of head and neck defects. These include the deltopectoral fascial flap, pectoralis major flap, and the latissimus dorsi flap. Bakamjian initially described the deltopectoral fascial flap for head and neck construction, but it has several shortcomings, including a lack of tissue bulk, unreliable distal perfusion when reconstruction is performed primarily, and the need for skin grafting at the donor site. As such, when Ariyan first described the use of the pectoralis major myocutaneous flap for head and neck reconstruction, it very quickly supplanted the deltopectoral fascial flap as the regional flap of choice.
Anatomy
The pectoralis major is a broad, fan-shaped muscle that originates from the medial clavicle, sternum, costal cartilages of the first through six ribs, and external oblique muscular aponeurosis. It inserts into the crest of the greater tubercle of the humerus. The pectoralis major muscle serves as an adductor, medial rotator, and extender of the arm.
The muscle is invested in the pectoralis fascia, which is distinct from the clavipectoral fascia that lies deep to it. The clavipectoral fascia is composed of the pectoralis minor fascia, subclavius fascia, costocoracoid ligament, costocoracoid membrane, and suspensory ligament of the axilla. This is important because the reconstructive surgeon uses the avascular plane between the clavipectoral fascia and pectoralis major fascia to raise the pectoralis major flap. The inferior free border of the pectoralis major forms the anterior axillary fold as it narrows to its insertion into the humerus. The superior and lateral boundary is with the deltoid muscle. The plane between to the deltoid and pectoralis major forms the deltopectoral groove and is marked by the cephalic vein, which runs within it ( eFig. 81.4 ).
The vascular supply to the pectoralis major is based off branches of the axillary artery. The thoracoacromial artery is a branch off of the middle portion of the axillary artery, deep to the pectoralis minor. This artery has four main branches: the pectoral, clavicular, acromial, and deltoid. The pectoral branch runs along and around the medial aspect of the pectoralis minor, pierces the clavipectoral fascia along with the medial and lateral pectoral nerves, and runs inferiorly and obliquely along the deep aspect of the pectoralis major. It is the dominant pedicle of the pectoralis major muscle. However, the clavicular head has contributions from the deltoid branch; the medial portion of the pectoralis major is supplied by the internal mammary artery perforators, which are branches from the superior thoracic artery; and there can be important contributions by the lateral thoracic artery. The superior thoracic artery branches from the first portion of the axillary artery over the first intercostal space. The lateral thoracic artery branches from the middle portion of the axillary artery at the lateral edge of the pectoralis minor muscle ( Fig. 81.5 ).
