Papillary thyroid cancer is the most common type of thyroid cancer in America, but not worldwide. It occurs more frequently in women and presents in the 30-40 year age group. It is also the predominant cancer type in children with thyroid cancer, and in patients with thyroid cancer who have had previous radiation to the head and neck (in this group, the cancer tends to be multifocal with early lymphatic spread, and portends a relatively poor prognosis).
Characteristic Orphan Annie eye nuclear inclusions and psammoma bodies on light microscopy. The former is useful in identifying the follicular variant of papillary thyroid carcinomas.
Lymphatic spread is more common than hematogenous spread
Multifocality is common
The so-called Lateral Aberrant Thyroid is actually a lymph node metastasis from papillary thyroid carcinoma.
There are at minimum 13 known scoring systems for prognosis; among the more often used are:
AGES - Age, Grade, Extent of disease, Size
AMES - Age, Metastasis, Extent of disease, Size
MACIS - Metastasis, Age at presentation, Completeness of surgical resection, Invasion (extrathyroidal), Size (this is a modification of the AGES system)
TNM - Tumor, node, metastasis. Remarkable about the TNM grading for (differentiated) thyroid carcinoma is that the scoring is different according to age.
Minimal disease (diameter up to 1.0 centimeters) - hemithyroidectomy (or unilateral lobectomy) and isthmectomy may be sufficient. There is some discussion whether this is still preferable over total thyroidectomy for this group of patients.
Gross disease (diameter over 1.0 centimeters) - total thyroidectomy, and central compartment lymph node removal is the therapy of choice. Additional lateral neck nodes can be removed at the same time if an ultrasound guided FNA and thyrobulin TG cancer washing was positive on the pre-operative neck node ultrasound evaluation.
Arguments for total thyroidectomy are:
Reduced risk of recurrence, if central compartment nodes are removed at the original surgery.
Papillary carcinoma is a multifocal disease (hemithyroidectomy may leave disease in the other lobe)
Ease of monitoring with thyroglobulin (sensitivity for picking up recurrence is increased in presence of total thyroidectomy, and ablation of remnant normal thyroid by low dose radioiodine 131 after following a low iodine diet (LID).
Ease of detection of metastatic disease by thyroid and neck node ultrasound.
Thyroid total body scans are less reliable at finding recurrence than TG and ultrasound.
^ Lin JD (2007). "Thyroglobulin and human thyroid cancer". Clin Chim Acta. doi:10.1016/j.cca.2007.11.002. PMID 18060877.
^ Tuttle RM, Leboeuf R, Martorella AJ (2007). "Papillary thyroid cancer: monitoring and therapy". Endocrinol. Metab. Clin. North Am.36 (3): 753–78, vii. doi:10.1016/j.ecl.2007.04.004. PMID 17673127.
^ Yang GC, Liebeskind D, Messina AV (2001). "Ultrasound-guided fine-needle aspiration of the thyroid assessed by Ultrafast Papanicolaou stain: data from 1135 biopsies with a two- to six-year follow-up". Thyroid11 (6): 581–9. doi:10.1089/105072501750302895. PMID 11442006.
^ Escofet X, Khan AZ, Mazarani W, Woods WG (2007). "Lessons to be learned: a case study approach. Lateral aberrant thyroid tissue: is it always malignant?". J R Soc Health127 (1): 45–6. PMID 17319317.
^ New York Thyroid Center: Prognosis Staging for Thyroid Cancer. Retrieved on 2007-12-22.