Thyroid-Parotid Gland Surgery

Differentiated thyroid cancers and its variants in the past 2 decades have doubled its incidence in the western sphere . This increased incidence has in part been attributed to the widespread screening of all suspicious neck masses with ultrasound scan (US )and fine needle aspiration cytologic biopsy of suspicious nodules in and around the thyroid gland . Fortunately all these newly picked up cancers are < 1 centimeter which is associated with minimal tumor associated morbidity and has a cure rate of 97 % at 20 years ( Memorial Sloan Kettering data N.Y USA ). There are still other centers in Japan ( Ito et al Kurumi cancer center,Japan ) who believe that if the patient is willing to adhere to a strict regular follow-up they can be observed periodically with a high quality US examination based on the common observation that these small tumors are extremely slow growing with little and no long term tumor related morbidity and mortality. . Suffice to state the prognosis amongst thyroid cancers can be well predicted based on the their risk stratification which take into consideration factors such as age and sex of the affected individuals , as well as tumor size , grade , extra-thyroidal extension nodal and distant metastasis. Those that fall in the low risk group have a 20 year survival of 97 % while those that have been stratified to fall in intermediate and hi risk group have survival of 76 % and 57 % respectively over the same time period . Considering the low cancer related morbidity and mortality thyroid cancers even the high risk are well worth considering for curative treatment . Most low risk tumors will be scheduled for lobectomy and isthmectomy with extremely gratifying functional and oncologic outcomes ( Vide supra ). Those that follow in the other 2 groups have worser outcomes but compared to the HNSCC there is little doubt that these tumors have a good outcome with surgery that now involve removal of entire thyroid gland and also address electively the removal of first echelon of lymphatic deposits Viz. the ipsilateral paratracheal nodes and thereuptically whichever lymphatics are radiological or clinically evident . Those that after surgery have sinister biologic portent will benefit from radioiodine ablative therapy that has to be carried out at a department that has both trained nuclear physicians and lead shielded isolation rooms/wards . Following this most of the intermediate and hi risk patients will be kept under replacement +/- suppressive oral iodine to maintain the serum TSH at/ >1 Iu/L in the former and between 0.1 and 0.5 IU for the latter . Overt dose for Serum TSH suppression is to be avoided particularly in the hi risk group as it can precipitate acute cardiac toxicity in form of rhythm alterations and may lead to osteopenia in those over a prolonged period . A serum TSH estimation prior to initiation of treatment is highly recommended . This will differentiate between those tumors that may be ‘TSH driven’ have a high TSH before any surgery and those that have low TSH and may not be influenced by TSH . In the hi-risk elderly patients a low TSH would be indicative of an aggressive biology with possible de- differentiation of the papillary cancer . Such undifferentiated tumors will have very aggressive clinical behavior which may mandate PET- SCAN ( rather than diagnostic whole body radioactive iodine scan ) for diagnosis of the full extent of the tumor and these tumors by virtue of their inability to absorb radioactive iodine will fall outside its thereuptic ambit . These patients may require other forms of adjuvant therapy like external beam radiotherapy and/ or monoclonal antibodies . Such patients should be offered a guarded prognosis as their survival is likely to be adversely affected by the disease process.

The other tumors that are less commonly encountered in the H&N area include the salivary gland lesions that occur in the major and minor salivary glands in the region of H& N . These tumors are infrequent and have a fairly good treatment outcomes compared to the squamous cancers because of an indolent biology in the low grade and intermediate grade histology. However the high grade tumors like adenoid cystic cancers have a predilection for perineural spread and are known to have distant metastatic potential especially to the lungs which mandates regular examination in locoregionally controlled patients . Further still amongst children , there are tumors of the eye viz the retinoblastoma , tumors of the mesenchymal system i.e. The embryonal rhabdomysosarcomas , as well some x- linked syndromic varieties such as the retinitis pigmentosa , medullary carcinoma , as well xeroderma pigmentosa . The interest amongst childhood cancers is the recent understanding of genetic transmission that has helped counsel parents prior to [planned conception in families with with these diseases. .