Level 2b Node dissection- To excise or not exicise

Level II b node removal in routine neck dissection

1. II B – To Excise Or To Not Author:-Dr Rahul Deshmukh , Dr Nitin Bhola , Dr Bhushan Mundada Dept of Maxillofacial and Plastic Surgery, DMIMS (DU) …???????

2. Introduction:- Lymph node metastases from squamous carcinomas of the oral cavity cancer tend to exhibit a typical pattern of spread, most frequently to levels I, II, and III. As is evident, contiguous levels are cleared and level II is included in all variations of SNDs. Although metastases to these levels are well demonstrated, there is debate about the frequency of metastases to the level IIb sub site of level II.

3. . The course of the spinal accessory nerve divides level II into two parts and the postero - supero -lateral part is named level IIb or the submuscular recess . Because of the small confines of this nodal level, traction of the spinal accessory nerve is often required to safely deliver the lymph node bearing tissue from this region.. This dissection accounts for the temporary and occasionally permanent shoulder dysfunction and disability.

4. . The clinical assessment of IIb nodes is often difficult as they are present deep to the SCM and may not be palpable or detectable on sonography . Micro-metastasis may also be missed on these investigations and if not addressed can lead to recurrence. Hence there is dilemma for the surgeon whether to address these nodes or not.

5. . Thus a study was undertaken in the Department of Oral and Maxillofacial surgery , Sharad Pawar Dental College and Acharya Vinoba Bhave Rural Hospital, Sawangi ( Meghe ); Wardha , to evaluate the incidence of level IIb lymph node metastasis histopathologically in oral squamous cell carcinoma.

6. Material and Method:- This prospective study was being carried out over a period, from 1 Oct 2011 to 1 Aug 2013. 55 Consecutive patients of squamous Cell carcinoma who underwent neck dissection were included in the study irrespective of age, sex, religion, caste, anatomical site, clinical stage and histological grading .

7. . A detailed case history for all the patients was recorded and on the basis of clinical findings, the TNM staging of tumor was done. Clinically lymph nodes were accessed for their number, size, shape, site, consistency and fixity to decide whether the palpable nodes were malignant or inflammatory.

8. . Patients were also evaluated for the neck node metastasis by using Ultrasonography (USG) and the detected nodes were assessed level wise for their number, size, shape, site, central necrosis, echogenecity , extracapsular spread, roundness index and hilum distortion.

9. . Patient underwent the surgery which included 1) Wide local excision of lesion 2) Suitable Neck dissection, depending on the merit of the case. 3) Reconstruction Paraffin embedded block of the gross lymph node tissue were prepared and subjected for multiple sections followed by conventional H/E staining.

10. Observation and Results:- Age and gender wise distribution of patients In the present study out of 55 subjects , males were significantly higher i.e. (81.81%) than female patients (18.18%). The mean age of the patients included in the present study was 49.6 years and maximum patients (76%) were between the ages of 30-60 years. The metastasis in level IIb lymph nodes was observed in 5 males (9.09%) and in 1 female patient (1.81%) out of total 55 patients. There was no gender variation as far as metastasis to level IIb lymph node metastasis concerned.

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12. Distribution of patients according to primary sites In present study out of 55 patients, 23 patients (41.81%) had SCC of lower GB sulcus , 19 patients(34.54 %) had Squamous cell carcinoma of buccal mucosa, 5 patients (9.09 %) had SCC of tongue, 3 (5.45 %) patients had SCC of lower gingivo labial sulcus rest had SCC of lower lip, floor of mouth, upper vestibule and palate. Present study found positive level IIb lymph node metastasis in 3 patients (15.78%) who had SCC of Buccal mucosa, 2 patients (8.69 %) who had SCC of lower posterior GB sulcus , 1 patient (20%) who had SCC of tongue.

13. . 41.81 % 34.54% 9.09%

14. Distribution of patients according to diagnosis In our study maximum i.e. 28 patients (50.90 %) were diagnosed with Well differentiated SCC, 24 patients (43.63 %) with moderately differentiated SCC and 3 patients (5.45 %) with poorly differentiated squamous cell carcinoma. We found maximum positive metastasis to level IIb lymph node in 5 patients (20.83 %) who had moderately differentiated SCC and 1 patient (3.57 %) who had Well differentiated SCC.

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16. Distribution of patients according to clinical staging Maximum patients reported and included in our study i.e. 40 patients (72.72%) with clinical stage of IVa , 10 patients (27.27%) with stage III, 3 patients (5.45%) with stage IVb , 2 patients (3.63%) with stage II. No patients with stage I reported/included in our study. We found that maximum i.e. 5 patients (12.5 %) out of 40 patients with stage IVa had positive metastasis to level IIb lymph node, 1 patient (10 %) out of 10 patients with stage III also had positive metastasis to level IIb lymph node.

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18. Discussion:- Along with the success in loco-regional control of cancer patients by radical neck dissection, problems like the long term disabilities resulted from such extensive operation. In 1952 , Ewing and Martin addressed the issue of disability of following radical neck dissection. They noted that 47 patient noted a shoulder droop, 42 patients noted discomfort in shoulder region, and 60 noted a reduction in the range of movement in shoulder. $ This was due to sacrifice of spinal accessory nerve, which is considered to contribute most motor innervations to the trapezius muscle.

19. . The aim of SND is to reduce morbidity by preserving the spinal accessory nerve, the sternocleidomastoid muscle, and the internal jugular vein. Morbidity caused by nerve injury is a greater source of persistent problems than the other 2 structures. The accessory nerve is important in supplying motor function to the trapezius in the majority of patients, and sacrifice of this nerve causes significant shoulder dysfunction and pain.

20. . Bocca and Pignataro (1967) pointed out that, in the upper portion of the neck, the spinal accessory nerve courses directly through node bearing tissue, which is eponymously named as “ Bocca’s triangle Level IIb ( submuscular recess or posterior triangle apex) is known as the site of primary lymphatic metastasis in malignant tumors originating from skin of the head and neck area, the nasopharynx , and the sinuses ,but there is debate about the frequency of metastases to the level IIb sub site of level II and inclusion of level IIb in neck dissection as a routine procedure inspite of spinal nerve injury caused during its resection.

21. . Comprehensive analysis of these previous studies suggests that, considering the low incidence of level IIb nodal metastasis in head and neck SCC, it is unnecessary to resect level IIb lymph nodes when performing END. However, each study has its limitations. In order to decide whether the preservation of level IIb lymph nodes is an oncologically safe procedure, the level IIb metastasis rate must be determined for each of the primary sites and the study should include only those cases that were surgically treated as initial therapy.

22. . Our study intended to correlate positive metastasis to level IIb lymph node with parameters like site, histological grade and clinical stage of malignancy.

23. . In this study the gingivo-buccal sulcus was the most frequently involved site followed by buccal mucosa .Most of the patients tend to keep the tobacco in the form of quid in the buccal sulcus with close proximity to gingiva in this region. This may explain the increased incidence of OSCC of the GB sulcus in this study. Until now correlation of incidence of level IIb lymph node metastasis with Broader’s grades of OSCC ( i.e Well, Mod, Poor) remained unexplored. This is a first attempt to establish correlation between them.

24. . Our study reported that, incidence of positive metastasis in level IIb lymph node in well differentiated squamous cell carcinoma was (3.57 %), in moderately differentiated squamous cell carcinoma was (20.83 %), but might be because of less number of cases ( i.e total 3 cases) in poorly differentiated squamous cell carcinoma incidence was found to be (0%).

25. . Present study reports maximum incidence of positive metastasis to level IIb lymph node in patients with stage IVa OSCC followed by patients with stage III OSCC .This may suggest that there is increased risk of level IIb metastasis in advance stages. The uniqueness of present study lies in the facts that The study shows correlation between primary site of OSCC and prevalence of metastasis to level IIb lymph node The study establishes correlation between Broader’s grading of OSCC and incidence of level IIb metastasis. The study reports cases of positive metastasis in level IIb lymph node with primary site of OSCC in buccal mucosa and posterior GB sulcus

26. . However, there are some limitations like The study does not consider the use of advanced molecular techniques to detect incidence of positive metastasis (e.g. IHC) The study does not consider the depth of tumor and its correlation with incidence of metastasis to level IIb lymph node The study constitutes less number of cases with T1 and T2 stage of OSCC. The study constitutes very less number of cases with N0 neck involvement in OSCC, to comment on incidence of level IIb metastasis in N0 neck.

27. Conclusion Prevalence of level II b lymph node metastasis is higher in cases with i ) Advance stages, ii) Lesser degree of cellular differentiation , iii) Primary site of lesion with lower posterior GB sulcus , buccal mucosa and tongue.

28. Present study suggests …….. Resection of level II b lymph node should be done in Cases involving primary site of buccal mucosa, tongue and lower posterior GB sulcus . Cases with advance stages (III & IV). Cases with lesser degree of differentiation.

29. Preservation of Level II b lymph node can be done in Stage I / Stage II patients. Patents who can come for regular follow up.