Case 5 :   CA floor of mouth

Surgeon: Malika Rumpradit

HN : 42 – 168623

History

       Thai man 66 years presents with painless mass with ulcer at anterior floor of month for 5 months. He has difficulty swallowing and speaking due to restriction of movement of tongue. He has no problem with drooling, sore throat, dysplagia or hoarseness.

       The incision biopsy was done at the Rajburee Hospital.  The pathological reported Squamous cell carcinoma, well differentiation.  The patient was referred to Siriraj Hospital.

       He is a cigarette smoker 1 pack/day for 20 years and an occasional alcoholic drinker for 20 years.

Physical examination

       Vital signs: Within normal limit.

       General appearance: Not pale, no jaundice, no cachexia.

       Head & neck region: The exophytic, ulcerating mass is occupied in anterior 2/3 of floor of mouth and involved the volar surface of tongue, anterior 1/3.The chin is slightly protruded.

                                : No drooling, no trismus.                                        

                                : No otalgia. No hoarseness of voice.

                                : Pharynx and tonsil appear normal.

       Cervical lymph node: 2 lymph node enlarge at left upper jugular chain, diameter 1.5 and 2 cm.soft,mobile, not fixed with deep structure. 1 lymph node enlarged at right submandibular region diameter 1 cm. mobile, rubbery consistency.

       Heart: Normal S 1, S2, no murmur.

       Lungs: Normal breath sound, no adventitious sound

       Abdomen: Soft, not tender, no hepatosplenomegaly

Extremities: Grossly normal


 



Figure 1. Preoperation

Investigation

       The chest X-ray: No pulmonary nodule.

       The Esophagogram: No evidence of intrinsic mass or extrinsic pressure effect along course of esophagus.

       The ultrasound liver: Normal parenchymal and echogenicity.  No space–occupying lesion. No evidence of liver metastasis.

       CT scan head & neck region: The study reveals soft tissue mass with enhancement and irregular boarder at floor of mouth.  The mass located predominate in left side more than right side, but right side of mandible symphysis shows bony destruction. The infiltrative mass in tongue is not evaluated.  The cervical lymphadenopathy is not visualized. The other parts are unremarkable.


Figure 2. CT scan of head and neck

Diagnosis

       Squamous cell carcinoma, anterior floor of mouth Stage IV (T4N2Mo)

Operation

       Wide excision with 3 cm margin of soft tissue.

       Segmental mandibulectomy

       Functional neck dissection, left.

       Supraomohyoid neck dissection, right.

       Fibula osteoseptocutaneous free flap transfer.

 

Findings

       The mass occupied 2/3 anterior floor of month involved volar surface 2/3 left side of tongue. The bony (mandible) involvement extended from 5 cm.from left mandibular angle across midline to 1 cm.from symphysis. The submandibular and upper jugulodigastric nodes were enlargement in vary size, rubbery and mobile on the left side. The submandibular lymph node also enlarged 2 nodes 1 cm. in diameter, soft, mobile.

 

 

Procedure

       The tracheostomy was performed. And the general anesthesia was obtained. The patient was positioned in extended neck. The tourniquet was placed at right thigh. The head, neck, upper chest and both legs were prepared and draped.

 

Neck dissection

       The neck dissection was performed on the left side. The incision was done from submandibular along the anterior sternomastoid muscle and curve superior to clavicular line refer to Ariyan’s 1980.

       The skin flap was dissected over the platysma, care must be taken to identify and preserve the facial nerve, mandibular and cervical branch. The sternocleidomastoid muscle was identified and removed. The spinal accessory nerve was identified and protected. The dissection started from the posterior triangle. All of the fatty tissue and lymph node were removed. The Internal and external jugular veins were double ligated and resected including the surrounding lymph nodes. The submandibular and submental lymph nodes and tail of parotid gland were also removed. The lingual artery, hypoglossal nerve was preserved. The dissection was done to the supraclavicular region.  The supraomohyoid neck dissection was performed in on the right side by the same incision.  The lymph node in the submandibular triangle and upper and mid jugulodigastric were removed downward to the omohyoid muscle level.  The facial vessels and external vein were identified and remarked with vessel loops.

 

Tumor excision

       The lower midline incision was done at lower lip. The wide excision was done with 2 cm. margin of soft tissue include the volar surface anterior 2/3 of tongue. The segmental mandibulectomy was done by sagittal saw 3 cm from angle and cross midline 3 cm from the symphysis. The defect was 15 cm length of mandible and 15x8 cm.of floor of mouth.

 

Donor site preparation

       The fibula osteoseptocutaneous free flap was harvested via lateral approach. The knee is flexed 135 degrees, the hip is flexed 60 degrees and the leg was internally rotated. The measurement was done from fibular head to the lateral malleolus. The middle third of fibula was marked. The skin paddle was outlined size 15x8 cm.centered as marked point. The tourniquet was raised 500mmHg.The incision was done along the anterior margin. The septocutaneous perforators were identified and preserved.  The superficial peroneal nerve was also protected. The dissection was inferiorly by crural fascia to the peroneus muscle to the posterior muscular septum. The posterior incision was done deeply to the soleus muscle and to the fibula by extraperiosteal dissection. 1-3 mm. muscle cuff of peroneus and soleus were left with the fibula. The peroneal artery was identified at the distal fibula. The distal osteotomy was done with a sagittal saw; the peroneal artery was ligated and traced upward with the fibula to the posterior tibial vessel. The flexor hallucis longus and tibialis posterior muscle was cut with 1-3 mm. cuff left. The tourniquet was released, the blood supply was ensured. The fibula was segmental osteotomy to contour the mandible by template from the lesion.The reconstruction plate was fixed to the fibula free flap before harvested. The split thickness was harvested from left thigh and grafted on the donor site.

 

 

 

Flap inset

       The plate was fixed with the mandible. The skin paddle was sutured with the defect by chromic 4-0 to form the floor of mouth. The microvascular anastomosis was performed by nylon 9-0.The peroneal artery was anastomosed to the facial artery, end to end. The two venae commitants were anastomosed to the facial vein, end to end and the external jugular vein, end to side. The flap was well perfused without congestion. Two radivac drains were place beneath the neck flap away from the anastomosis. The subcutaneous and platysma were sutured with vicryl 4-0.The skin was closed by nylon 6-0.

 


 


Figure 3.  The defect and tumor specimen.


 

 


Figure 4. The fibula flap and flap inset.

Postoperative care

       The patient was placed with a slightly elevated head. The flap was clinically observed for viability by the skin paddle perfusion and degree of congestion every 4 hours until 5 days. The nasogastric tube was fed by blendarize diet in 3 days postoperation due to well recovery of the patient. The radivac drains were removed 5 days postoperation after no increased content.  The flap is completely survived.The stitch was removed in 1 week. No donor site morbidity.

 

The pathological report

       Floor of month and segment of mandible: Squamous cell CA well differentiation involved the whole floor of mouth with, tongue   bone and muscle invasion. All surgical margins are tumor free.

       Left neck node: Metastatic Squamous cell CA in 5/36 nodes.

       Salivary gland: Invaded by tumor.

       Right submandibular gland: Metastatic Squamous cell CA in 1/3 nodes.

       Right supraomohyoid node: No tumor identified.

 

Planning of treatment

       The radiation 6,000 cGy was given 3 weeks postoperation.


      

 


Figure 5. 3 weeks postoperation

Discussion

 

Squamous cell carcinoma is a malignant tumor of epithelial origin and the most common cancer of the upper aerodigestive tract in humans, account­ing for 90% to 95% of oral cancers alone. In its initial stages squamous cell carcinoma often mimics benign processes of the mouth such as leukoplakia and herpes. Early lesions may be asymptomatic or cause only minor symptoms, delaying diagnosis.

 

Epidemiology

In 1996 approximately 29,500 new cases of can­cer of the oral cavity, pharynx or larynx will be diagnosed. An estimated 8,260 of these patients will eventually die of their disease. The incidence of newly diagnosed cancers of the pharynx and larynx has been rising slowly in recent years. Cancers of the oral cavity are most frequent dur­ing the 6th, 7th, and 8th decades of life. With increasing age there is a corresponding rise in frequency of oral mucosal lesions, particularly for denture wearers (27%). One-fourth of denture ­related lesions are ulcerated, and people who have these so-called traumatic ulcers are at high risk for developing squamous cell carcinoma.

 

Etiology and Risk Factors

Risk factors in oropharyngeal cancer include oc­cupational agents, tobacco, alcohol, nutrition, chronic infection, therapeutic side effects, hered­ity, and oncogenic viruses.

Moore emphasizes that tobacco is the main cause of squamous carcinoma in the mouth and throat. Forty percent of patients with carcinomas of the oral cavity who continue smoking develop second cancers, com­pared with 6% of those who quit. The use of cigarettes is associated with increased risk of cancer in all sites of the head and neck except the salivary glands; at highest risk are the floor of the mouth and the larynx. Cigar smoking is associated with increased risk of cancer of the tongue, pharynx, and larynx, while pipe smoking is linked to cancer of the tongue, mouth, pharynx, and larynx. Patients who both smoke and drink are at highest risk, especially for cancer of the hypopharynx.

The nicotine addiction caused by tobacco use is strong. A recent study showed that 35% of patients with newly diagnosed head and neck cancer con­tinued to smoke after treatment. Patients who continue to smoke during radiation therapy have lower rates of response and survival than patients who do not smoke during therapy.

Approximately 11 % of cancers of the head and neck will have separate foci of in situ carcinoma or isolated islands of invasive squamous cell carcinoma in continuity with or near the primary tumor. This observation lends support to the theory of “field cancerization,” which holds that an area of epithelium is preconditioned by a carcinogenic agent.

 

 

 

 

 

 

 

 

 

 

Figure 6.  Frequency of cancer in the oral cavity by anatomic site.

 

Leukoplakia

Leukoplakia is a white keratotic patch on the mucosa of the mouth that cannot be scraped off or diagnosed as anything else. Leukoplakia and erythroplasia are two of the most common lesions associ­ated with intraoral cancer: in leukoplakia, 11% to 16% of lesions are dysplastic and 3% to 5% will become carcinomas. Erythroplasia is associated with in situ or invasive lesions in 54% to 64% of cases.

Diagnosis

       Ulcerations of the oral mucosa should always be viewed with suspicion, especially if they do not heal quickly. A painless, isolated firm granular ulcer in an older patient or high risk factor should be considered cancerous until proved otherwise.

       The patient must have thoroughly head and neck examination. The intraoral, orophalynx and hypophalynx should be examined. The

Bilateral palpation of the neck is an important adjunct to the initial examination. The lesion can biopsy by exfoliative cytology, fine needle aspiration incision and excision biopsy.Depending on the size of lesion and experience of the pathologist.

The imaging studies compliment the physical examination the evaluation of the head and neck. CT scan is the investigation of choice to evaluate most tumors in this area. CT scan provides an excellent view of the extent of the tumor and an opportunity to look for nodal metastasis. MRI can provide an excellent image for soft tissue and remarkable contrast between tumor and normal structures. It cannot define the osseous structure as well as CT and limited its use.

 

Staging

Staging systems in head and neck cancer are based on clinical examination and aim at produc­ing the best possible estimate of the extent of dis­ease before first treatment.

TNM CLASSIFICATION

 

T = extent of the primary tumor

N = state of regional lymph nodes

M = metastases

The number appended to each component indicates the state of the disease in relation to that component.

TNM Pretreatment Clinical Classification

T          Primary tumor

Tis       Preinvasive cancer (carcinoma in situ)

T0       No evidence of primary tumor

T1       Tumor 2 cm or less in greatest dimension

T2       Tumor more than 2 cm but not more than 4 cm

T3       Tumor more than 4 cm

T4       Tumor with extension to bone muscle, skin, antrum, neck, etc.

Tx        Minimum requirements to assess primary tumor cannot be met

 

N         Regional lymph nodes

N0       No evidence of regional lymph node involvement

N1       Evidence of involvement of movable homolateral regional lymph nodes

N2       Evidence of involvement of movable contralateral or bilateral regional lymph nodes

N3       Evidence of involvement of fixed regional lymph nodes

Nx       Minimum requirements to assess the regional nodes cannot be met

 

M         Distant metastases

M0       No evidence of distant metastases

M1       Evidence of distant metastases

Mx       Minimum requirements to assess the presence of distant metastases cannot be met

 

pTNM Postsurgery histopathologic classification

pT        Primary tumor—categories correspond to the T categories

pN       Regional lymph nodes—categories correspond to the N categories

pM       Distant metastases—categories correspond to the M categories

One of the primary functions of the TNM system is to allow staging of disease. This system provides the means to accumulate more accurate statistics if applied correctly.

Staging

Stage 1   T1   N0   M0

Stage 2   T2   N0   M0

Stage 3   T3   N01  M0

Stage 4   T1   T2 T3 T4N1     M0

            Any T    N01N1   M0

            Any T    N2 N3   M0

            Any N    M1

 

Although these categories are convenient forms of shorthand, they can be applied only if assessment is accurate. This statement particularly applies to estimate of size, which can be grossly inaccurate, particularly regarding depth of involvement.

Intraoral tumors are best grouped into the areas involved: tongue, floor of mouth, alveolus (lower), alveolus (upper), palate, buccal, tonsillar fossa, jaws. With some more extensive tumors, the exact location of origin is difficult or impossible to determine.

In 1988 the American Joint Committee on Cancer (AJCC) and the Union International Contra Cancer (UICC) made minor changes in the old T (tumor) classifica­tion and several major changes in the previous N (nodal) classifications for staging cervical node me­tastases. The new clinical staging criteria are listed in Table 1.

 


 

 


Preoperative Screening

At the time of initial evaluation, patients should have chest x-ray films, liver function tests, and alka­line phosphatase assay. If any test is abnormal or if the patient has symptoms, site-directed CT scans, liver sonograms, and bone scans should be per­formed to rule out distant metastases.

 

Neck dissection

       Terminology has been standard­ized as follows:

1.     Suprahyoid neck dissection

2.     Supraomohyoid neck dissection: Contents of the submandibular triangle, jugulodigastric, and mid-jugular lymph nodes together with nodes from the posterior triangle along the accessory chain are removed.

3.     Modified radical neck dissection

4.     Functional neck dissection: The accessory nerve alone is spared.

5.     Radical neck dissection.  

 

Indications for Elective or Prophylactic Neck Dissection

Elective neck dissection should be considered in high-risk patients such as those with T2 lesions of the floor of the mouth, tongue, tonsils, supraglottic larynx, and alveolar ridge.  O’Brien recommends elective modified neck dis­section in cases of T3 and T4 tumors and clinically negative nodes, or when primary resection is car­ried out through a neck incision; in other words, patients at high risk for occult metastatic disease in the neck.

Any patient who may be a candidate for elective neck dissection should have CT or MR scan, which is reported to be 91% sensitive in detecting occult nodal disease.

Radiotherapy

       Radiotherapy combined with tumor ab­lation and neck dissection achieves better control of local and regional disease than either form of treatment alone. Radiotherapy as a surgical adjuvant in head and neck cancer seems to be equally effective whether it is administered before or after surgery.

  The indications for postoperative radiation therapy include positive or close surgical margins; large (T3 orT4) primary tumors; nodes >1 cm; multiple posi­tive nodes; nodes with extracapsular involvement by tumor; and tumor invasion of vascular, lymphatic, perineural tissues, or bone. The decision for ad­junctive radiotherapy is made only after reviewing the operative and pathologic findings and evaluat­ing the individual patient’s clinical status. Advo­cates of postoperative radiotherapy (60 Gy) claim that it does not increase surgical morbidity so that a higher dose may be given and does not interfere with wound healing..

 

Chemotherapy

Chemotherapy is most effective when administered preoperatively, before the blood vessels and lymphatics to the tumor are disturbed by surgery. The response rate to cis-platinum and 5-FU ranges from 85% to 95% (54% complete responses). Patients who respond completely have an actuarial survival advantage of 70%, compared with 56% for patients who receive the standard treatment.              

In one se­ries the 22-month survival after 4-day continuous infusion of cis-platinum was 79%318 By itself, cisplatin infusion gives an overall response of 68%. Intraarterial infusion of combination vin­cristine, bleomycin, and methotrexate gives a re­sponse rate of 87.5%; cisplatin and bleomycin re­sult in 74.2% responses.  Cisplatin adversely af­fects healing wounds during the proliferative phase, as reflected by significantly reduced wound strength by day 10.

 

Prognostic Factors

       Prognosis in CA floor of mouth defines as stage I and II lesions have 70 to 90% 5-year cure rates with excision and interstitial radiotherapy. Large lesions have a much poorer prognosis, ranging from 30 to 60%. The overall 5-year survival rate has been reported as 65%97.

 

Mandibular reconstruction

       Specific functional goals include preservation of tandem temporomandibular joint action with maximal opening ability and maintenance of occlusion. Key aesthetic goals include symmetry, preservation of lower facial height and anterior chin projection, and correction of submandibular soft tissue neck defects.

     Mandible reconstruction can be accomplished by a variety of means, which include nonvascularized bone grafts, metal plates, pedicled flaps, and free flaps. Osteocutaneous free flap reconstruction is often the most effective method of mandible repair. These flaps have both soft tissue and bone components.

 

 Donor Site selection

DonorSite     Bone     Skin     Pedicle  Location Morbidity

   Fibula           A          C            B              A           A

    Ilium            B           D           D            B            C

  Scapula          C            B           C             D            B

   Radius          D          A           A             C             D

 Table 2.  Free flap donor site comparison for mandible reconstruction Ranked in each category from best (A) to worst (D).

 

        The fibula flap is indicated for all anterior defects and most lateral defects. It is the flap of choice for the majority of mandible defects.  The periosteal blood supply is functionally of a segmental type, unlike the other donor sites. Osteotomies can be planned wherever necessary and can be placed as close as one centimeter apart without concern for bone viability. The vascular pedicle has sufficient length and is of large diameter. The flexor hallucis longus muscle is conveniently located along the posterior border of the bone. This muscle is ideal for filling in adjacent soft tissue defects in the submandibular portion of the upper neck. The skin island available with the fibula is reliable in approximately 91% of patients. It is thicker than the forearm skin but thinner than the scapula skin. A large skin paddle can be harvested for complex defects, but the donor site will require a skin graft.

      

References

1.     Ariyan S.,Chicarilli Z.N.Cancer of the upper aerodigestive system. McCarthy J.G.,ed. Plastic surgery. Philadelphia:W.B. Saunders Co.,1990 ; 5 : 3412-3436

2.     Jackson I.T.Intraoral tumors and cervical lymphadenopathy. Grabb and Smith’s,5thed.Plastic surgery.  1997 ; 1 : 439-450.

3.     Hidalgo D.A.Mandible reconstruction. Grabb and Smith’s,5thed.Plastic surgery.  1997 ; 1 : 559-567.

4.     Serafin D.The fibula flap. Atlas of microsurgical composite tissue transplantation.1996 Philadelphia:W.B. Saunders Co.,1996: 547-564

5.     Vasconez H.C.,Luce E.D.Carcinoma of the oropharynx..  Cohen M. ed.Mastery of plastic and reconstructive surgery,  1994 ; 2 : 921-930.

6.     Sanger J.R.,Yousif N.J.,Matloub H.S.Reconstruction of the mandible and the floor of the mouth..  Cohen M. ed.Mastery of plastic and reconstructive surgery,  1994 ; 2 : 982-997.

7.     Schusterman M.A.Microvascular free transfer of a partial fibula for mandible reconstruction. Grabb’s encyclopedia of flaps, 2nd ed.1998;1:765-772.

8.     Granick M.S.,Solomon M.P.,Hanna D.C.Benign and malignant tumors of the oral cavity. Georgiade Plastic, Maxillofacial and Reconstructive Surgery,3rded.1997 ;1: 406-417.