Study on nodal metastasis in neck

A cross sectional study was done in ENT Department, BSMMU from October 07 to March 08. An attempt has been made to evaluate metastatic neck node clinically. 60 cases were studied. Primary lesion identified in 53 cases (88.33%) and remain undetected in 7 cases (11.67%). Among primary sixty (60) diseases, 43 (81.13%) arises from upper aerodigestive tract which were squamous cell carcinoma & 10 (18.87%) came from thyroid & parotid gland. Commonest primary site was Larynx (36.67%). Majority (55%) of patients were age group 41-60. Unilateral lymph node was involved in 49 cases (81.67%), bilateral in 10 (16.67%), contra lateral in 1 case (1.66%), Single node in 22 (36.67%), Multiple in 38 (63.33%) cases. Size of the node >6cm was found in 24 cases (40%), 3-6cm in 20 cases (63.33%), <3cm in 16 cases (26.67%). Most of the involved nodes were in levelII. Key wards: Metastatic neck node, primary tumour metastatic neck disease. Many carcinomas within the head or neck will sooner or later metastasize to lymph nodes and various factors control the natural history of this event.5 Most carcinoma of the central head and neck metastasize to the lymph nodes in the deep cervical chain.6 A lymph node in the posterior triangle may represent a metastasis from the postnasal space. A secondary malignant node in the neck may also be due to a tumour below the clavicle; the lung, stomach and breast are common sites, although on occasion others can arise from a primary elsewhere in the body such as the ovary or testis.7 A cancer presenting with a node in the neck is four times more common in men than in women, with a mean age of 65 years in men and 55 years in women.2 Clinical examination still remains the most important method of assessing regional lymph nodes. Some nodes in the neck are difficult to palpate. Thus retropharyngeal and parapharyngeal nodes are almost impossible to detect by palpation until they are very large.8 Metastatic involvement of various lymph node regions usually progress from superior to inferior in an orderly fashion, but it has been shown that in some situations lymph node groups can be bypassed even in the normal lymphogram.7 CT scanning of the neck can certainly detect metastastic lymph nodes. The three CT criteria used to define a node as metastatic or not, are size, Bangladesh J of Otorhinolaryngology 2008; 14(1) : 15-22


Introduction
A malignant tumor always invades the surrounding structures.It eventually enters the channels like the lymphatics and blood vessels and group of cells are carried to the other parts where it sets up as anabolic spread, is called metastasis. 1 Malignant tumours in the head and neck region have a propensity to metastasize.As the cervical region is very much rich in lymphatic supply containing 200 lymph nodes out of 500 lymph nodes in the body which may get involved in the clinical course of head & neck malignancy. 2 The tumour can metastasize in ipsilateral and/or contralateral or bilateral neck nodes.As the tumour grows within a node, it enlarges and becomes indurated and rounded. 3The tumour eventually extends though the capsule of the lymph node and invades the surrounding structures, extension through the neurovascular bundle is relatively common and results in fixation. 4e of the most important factors in head & neck cancer is the presence or absence, level and size of metastatic neck disease.Many carcinomas within the head or neck will sooner or later metastasize to lymph nodes and various factors control the natural history of this event. 5st carcinoma of the central head and neck metastasize to the lymph nodes in the deep cervical chain. 6A lymph node in the posterior triangle may represent a metastasis from the postnasal space.A secondary malignant node in the neck may also be due to a tumour below the clavicle; the lung, stomach and breast are common sites, although on occasion others can arise from a primary elsewhere in the body such as the ovary or testis. 7A cancer presenting with a node in the neck is four times more common in men than in women, with a mean age of 65 years in men and 55 years in women. 2 Clinical examination still remains the most important method of assessing regional lymph nodes.Some nodes in the neck are difficult to palpate.Thus retropharyngeal and parapharyngeal nodes are almost impossible to detect by palpation until they are very large. 8tastatic involvement of various lymph node regions usually progress from superior to inferior in an orderly fashion, but it has been shown that in some situations lymph node groups can be bypassed even in the normal lymphogram. 7 scanning of the neck can certainly detect metastastic lymph nodes.The three CT criteria used to define a node as metastatic or not, are size, Bangladesh J of Otorhinolaryngology 2008; 14(1) : 15-22   .peripheral enhancement and central necrosis. 9MRI is at present being used in the assessment of cervical lymphadenopathy.Enlarged nodes and nodes with central necrosis are well demonstrated by MRI.Metastastic lymph nodes in the neck can be demonstrated by ultrasonogram, but distinguishing between inflammatory zand metastatic nodes is difficult. 10On occasion FNAC is helpful in demonstrating metastatic carcinoma in a lymph node.It may be helpful in the evaluation of a difficult clinical situation.For example in the assessment of a patient with an unknown primary tumour fine needle aspiration may be useful.In general, negative aspiration cytology is not sufficiently reliable and should be ignored. 8 metastatic neck disease, majority of cases have known primary sites and another portion of cases having unknown primary tumours.It is important to remember that in 90% of cases the primary tumour of a neck metastasis will be in the head and neck, and vigilant search above the clavicles will provide the primary tumour site in approximately 50% of cases. 2 In case of unknown primary, following the history and examination and more importantly radiology, the patient should be examined under a general anaesthetic which will allow the entire upper respiratory tract to be palpated; some small tumours, particularly in the tongue base and tonsil, can often better felt and seen and the nasopharynx can be carefully examined.If the tumour is discovered, a biopsy is taken and the examination completed.Often no tumour will be found and in this situation blind biopsies are taken of both sides of the nasopharynx and the tongue base and tonsillectomy performed on the side of the node. 5e prognosis for patients in whom the primary site is never discovered or in whom the primary site is not in head and neck, however is disastrous and treatment must be considered palliative. 11ta on 168 patients with a lower neck node metastasis presenting to the department of medicine, head and neck Oncology group, University of Liverpool, UK shows survival with posterior triangle metastasis is significantly better than supraclavicular metastasis.Laterality of metastasis had no effect on survival.There is no significant difference in survival between squamous and non squamous metastasis. 12

Aims & Objectives
The aims of this study were -(1) To find out the primary sites of metastatic cervical lymph nodes.
(2) To find out the level of involvement of lymph nodes in neck.
(3) To make the nodal staging.The incidence of metastatic neck node with known primary is eight times more common than that of the unknown primary.Among the sq.cell carcinoma of head-neck larynx is the most common site to present with metastatic neck node followed by pyriform fossa and nasopharynx.Among the tumours of nonsquamous origin thyroid gland shows higher cervical node metastatis followed by parotid gland.In the present series 60 cases of metastastic neck node had been studied.A Primary lesion could be identified in 53 (88.33%) cases.However primary sites remained undetected in 7 (11.67%)cases.A study in our country with the metastatic neck node shows 93.2% cases of known primary & 6.8% cases of unknown primary sites 14 .However, two studies carried out abroad showed similar rate of incidence.One in the Liverpool, England showed 89.3% cases of known & 10.3% cases of unknown primary and another in USA revealed about 90% cases of known & 10% cases of unknown primary 15,16 .

Table-IV
Among the primary sites 43 (81.13%)cases were seen to arise from squamous lining of upper aerodigestive tract & 10 (18.87%) cases were having a nonsquamous origin arising from thyroid (13.33%) & parotid gland (3.33%).The study shows that metastasis from thyroid gland carcinoma is not a very uncommon entity.The incidence of metastatic neck node of thyroid origin in other series varied from 6.25% to 9.5%.In the present series metastatic neck node of thyroid origin was found in 8 (13.33%) cases.The higher incidence in the present series might be due to the fact that there was no selectivity for either the site of primary tumour or the histologic type.
Among the known primary sites highest incidence of metastatic neck node was found with Ca-larynx (36.66%).All of them were located in supraglottis of larynx with either involvement of medial wall or extention into the pyriform fossa in 40% cases which may explain the high incidence of metastasis in case of supraglottic larynx.No glottic or subglottic growth was seen with neck node metastasis.
Incidence of carcinoma pyriform fossa was seen in 9 (15%) cases.4 (6.67%)cases of metastatic neck node were seen to take origin from nasopharynx, 4 (6.67%)cases from the tongue, 2 (03.33%) cases from buccal mucosa, 1 (1.67%) case from nose & 1 (1.67%) case from tonsil.Among the non-squamous origin, 8 (13.33%) cases were found to arise from Cathyroid & 2 (3.33%) cases from Ca-parotid.The study carried out with metastatic neck node at home & abroad show a diverse picture.In a study with metastatic neck node in the department of Otolaryngology Mount Sina Hospital & Sunnybrook Medical center, Toronto, 40% cases were found to arise from Ca-tongue, 20% from Ca-larynx, 20% cases Ca-floor of mouth, 7% from Ca-tonsil, 3% from Capalate & 10% from miscellaneous sites.The absence of selectivity for primary sites was the reason behind it as noted by them 17 .Another study with metastatic neck node in Khartoum Teaching Hospital, Sudan, most common primary site was found nasopharynx 18 .
It might be due to their social habits and genetic predisposition.Other studies showed highest incidence of metastasis from Ca-pyriform fossa 14 .
Fourty-seven (78.33%) patients were males & 13 (21.67%)were females with a ratio being 3.In 36 (60%) cases lymph nodes were found mobile & 24 (40%) cases were found fixed.Mobility of the node varied from 57% to 60% & fixity from 43% to 40% in a study carried out in Bangladesh 9 .In other study, fixity of nodes varied from 16.4% to 29.6% representing their early presentation once again.
While leveling of the lymph node, most commonly involved lymph node region was found to be level II (40%) followed by level II + III (30%).This is in agreement with most studies that the upper jugular lymph node chain is most commonly involved with head & neck nodal metastasis 18 .
The higher incidence of N2 stage of lymph node in our series is well reported by other Bangladeshi series. 5

Conclusion
Data presented in this study may considerably vary with any large series but since then since the cases were collected very carefully over a period of six months from a hospital of national reference level, the study might be of some credential reflecting certain facts.Though inflammatory neck disease is very common in our country, one should not forget the possibility of metastatic carcinoma in an adult presenting with a rapidly growing, hard, non-tender, lateral neck mass.While enlarged cervical node in an elderly patient should always be considered as metastatic until proved otherwise.Because delay in the diagnosis will eliminate the best opportunity for effective treatment with curative inten.
In case of growth in the nasopharynx, base of the tongue, oropharynx, larynx & pyriform fossa rigid endoscopic procedures were done under general anesthesia (G/A) & tissue diagnosis of non squamous cell carcinoma of thyroid gland & parotid gland was confirmed by excisional biopsy.
Inclusion criteria: Metastatic neck node with a known primary, both Squamous & non-squamous origin in head & neck region & those with an unknown primary were included in this study.Exclusion criteria: Metastatic neck node involving left supraclavicular or scalene nodes with a possible primary arising within the chest & abdomen were excluded from this study.Data Collection :After taking a comprehensive history every patient was subjected to a thorough physical examination with particular emphasis to ear, nose & throat region.Neck was examined very carefully for the presence of a primary disease as well as the site, size, number & level of lymph node involvement, their consistency & mobility.All cases were advised for FNA biopsy of enlarged neck node.Cases revealed metastatic deposits in enlarged neck gland in FNA biopsy entered into this series.Besides FNA biopsy of neck node, blood for TC, DC, Hb%, ESR, urine for R/E & a chest x-ray P/A view were done in all cases.X-ray soft tissue nasopharynx lateral view, X-ray PNS -OM view, CT scan of nose & paranasal sinuses, CT scan of larynx, CT scan of nasopharynx & base of the skull, thyroid scan, ultrasonography of thyroid gland, thyroid function test, FNA biopsy of thyroid & parotid swelling were done in selected cases as directed by clinical findings.Tissue was taken from primary sites for histopathological examination for the confirmation of malignancy in every case.

Table - V
Sex distribution of metastatic neck node(n=60)

Table - VIII
13vel of lymph node involvement for each separate type of known primary.It is difficult to give an exact figure of metastasis neck disease as only few studies are available in our country and most of the studies were carried out with cervical lymphadenopathy where metastatic neck node was described as one of the commonest cause of cervical lymph node enlargement in adults.13Morethan one third of the total body lymph nodes are distributed in the neck and certain areas of head and neck are studded with dense capillary network of lymphatics.So the rate at which neoplasm metastasize from them is very high.
67%) cases.In other studies hard & firm to hard lymph nodes were found in 87.5% to 90.5% cases & firm lymph node in 9.5% to 12.5% cases.