The Usefulness of Staining Lymph Nodes During Operations for Cancer Thyroid in Detecting the Nodes That Have Cancer
The Usefulness of Staining Lymph Nodes During Operations for Cancer Thyroid in Detecting the Nodes That Have Cancer
Detection of lymph nodes starting to be involved by cancer spreading from the thyroid gland
 during operation is useful. It saves the patient from having a second operation to remove
 these nodes later on when they become obvious. The problem is that there are many lymph nodes
 around the gland. The theory is that only one node will get the first spill of the tumour
 cells.

 In this study the investigators are trying to use an inert colored material to inject into
 the tumour. This should run in the same path as the tumour cells and should therefore stain
 the one lymph node that will be affected first should the tumour spread.

 The stained lymph node is excised and examined instantaneously for tumour affection. If it is
 found to be affected by the tumour, then the operation is extended to include removal of all
 its fellow lymph nodes. If it is found to be free from the tumour, then this patient does not
 have tumour spread.
The study includes 45 consecutive patients diagnosed as differentiated thyroid cancer by
 clinical examination and/or fine needle aspiration cytology (FNAC).

 Exclusion criteria are: previous neck surgery, pregnancy and known hypersensitivity to the
 dye used.

 An informed consent was obtained from all the patients. Peroperative workup includes history
 taking, clinical examination, relevant laboratory investigations including thyroid hormone
 assay, ultrasonography of the neck with special emphasis on the thyroid focal lesion and
 cervical lymph nodes. FNAC was attempted in all patients.

 All patients were then subjected to operation:

 A systematized surgical approach was adopted for the purpose of the study: this started by
 collar incision, development of sub-platysmal skin flaps and separation of strap muscles in
 the midline. This was followed by exposure of the thyroid gland; identification of the
 thyroid tumour; injection of the dye into the tumour; waiting for the dye to reach the lymph
 nodes; identifying the stained node; labeling it as the sentinel node (SLN); performing total
 thyroidectomy and bilateral central neck dissection.

 The resected specimen was fixed by formaldehyde, stained with hematoxylin and eosin and
 examined with light microscopy.

 If the SLN was found to be free of malignant deposits, it was further examined by
 immunohistochemical staining.

 Statistical analysis: Descriptive statistics were used to analyze demographic data.
 Sensitivity, specificity and predictive value of the SLN were calculated.

 The histopathological report of the excised specimen was considered the criterion standard.
Inclusion Criteria:

 -  Patient diagnosed to have differentiated thyroid carcinoma and has no detectable
 cervical lymphadenopathy.

 Exclusion Criteria:

 -  Previous neck surgery, pregnancy and known hypersensitivity to the dye used.