Papillary microcarcinoma is a subset of papillary thyroid cancer defined as measuring less than or equal to 1 cm. The highest incidence of papillary thyroid microcarcinoma in an autopsy series was reported by Harach et al. in 1985, who found 36 of 101 consecutive autopsies to have an incidental microcarcinoma. Michael Pakdaman et al. report the highest incidence in a retrospective surgical series at 49.9 percent of 860 cases. Management strategies for incidental papillary microcarcinoma on ultrasound (and confirmed on FNAB) range from total thyroidectomy with radioactive iodine ablation to observation alone. Harach et al. suggest using the term "occult papillary tumor" to avoid giving patients distress over having cancer. It was Woolner et al. who first arbitrarily coined the term "occult papillary carcinoma" in 1960, to describe papillary carcinomas ≤ 1.5 cm in diameter.Several variants are recognized, although classic papillary thyroid carcinoma is the most frequent: microscopic-follicular variant, diffuse-sclerosing variant, tall-cell variant, columnar-cell variant, hobnail variant, and others. The encapsulated-follicular variant, specifically when noninvasive, has been newly reclassified as the noninvasive follicular thyroid neoplasm with papillary-like nuclear features.Although papillary carcinoma has a propensity to invade lymphatics, it is less likely to invade blood vessels. These kinds of tumors are most commonly unencapsulated, and they have a high tendency to metastasize locally to lymph nodes, which may produce cystic structures near the thyroid that are difficult to diagnose because of the paucity of malignant tissue.
Also, the sternocleidomastoid muscle, jugular vein, and accessory nerve are to be removed if such procedure allows apparently complete tumor resection. If a significant amount of residual tumor is left in the neck, external radiotherapy has been indicated and has proven useful especially in those cases when the residual tumor does not take up radioiodine. After surgical thyroid removal, the patient waits around 4–6 weeks to then have radioiodine therapy. This therapy is intended to both detect and destroy any metastasis and residual tissue in the thyroid. The treatment may be repeated 6–12 months after initial treatment of metastatic disease where disease recurs or has not fully responded.Patients are administered hormone replacement levothyroxine for life after surgery, especially after total thyroidectomy. Chemotherapy with cisplatin or doxorubicin has proven limited efficacy, however, it could be helpful for patients with bone metastases to improve their quality of life. Patients are also prescribed levothyroxine and radioiodine after surgery. Levothyroxine influences growth and maturation of tissues and it is involved in normal growth, metabolism, and development. In case of metastases, patients are prescribed antineoplastic agents which inhibit cell growth and proliferation and help in palliating symptoms in progressive disease. After successful treatment, 35 percent of the patients may experience a recurrence within a 40-year span. Also, patients may experience a high incidence of nodule metastasis, with 35 percent cases of cervical node metastases.