Thyroid Malignant Pathology PDF

THYROID CANCER  the most common endocrine neoplasia; approx. 1% of all malignancies; Epidemiology appears at ages between 40-65 years; women being more often affected; the women/men ratio being 2/1;  Main risk factors: ♦ in the etiology of papillary and follicular cancers = exter...

THYROID CANCER  the most common endocrine neoplasia; approx. 1% of all malignancies; Epidemiology appears at ages between 40-65 years; women being more often affected; the women/men ratio being 2/1;  Main risk factors: ♦ in the etiology of papillary and follicular cancers = external irradiation of the head and neck with reduced doses of ionizing radiation; - 4% of thyroid cancer patients have a history of radiotherapy. - after the atomic bomb attacks in Japan and the Chernobyl nuclear accident => increase in the incidence of papillary thyroid cancers. ♦ in medullary thyroid cancers = the genetic factor plays an important role. Clinical diagnosis asymptomatic thyroid nodule; other times with signs of compression, by increasing the size of the nodule; in the advanced stages pain and dysphagia appear; in < 5% of cases the onset with laterocervical ganglion metastases; the onset is rarely with distant metastases; Paraclinical diagnosis Ultrasound: highlights the nodule; allows the differentiation between nodules with solid content versus those with liquid content; Thyroid scintigraphy represents the imaging investigation of choice; it is performed with Iodine 131 or Technetium; "cold" nodules determine the suspicion of malignancy; only 10% of cold nodules are carcinomas; Puncture biopsy is performed with a needle; it is targeted at the thyroid nodules; ♦ the pre-therapeutic balance to highlight possible metastases includes: - standard chest x-ray; - liver ultrasound; - bone scintigraphy; ♦ among the biological explorations are useful: - dosage of calcitonin - of carcioembryonic antigen, which are present in medullary carcinomas TNM classification ( UICC 2002 ) of thyroid cancers T = tumor T0 = ​no evidence of primary tumor Tx = primary tumor not evaluable T1 = tumor of 2cm or less in maximum dimensions; - limited to the thyroid T2 = tumor >2cm ≤4cm in maximum dimensions; - limited to the thyroid  T3 = tumoră > de 4cm în diametrele maxime, limitată la tiroidă T4- orice tumoră cu extensie minimă extratitoidiană (ex. extensie la muşchiul sternocleidomastoidian sau ţesut peritiroidian); T4a = tumoră de orice dimensiune, extinsă dincolo de capsula tiroidiană invadând ţesuturile moi, laringele, trahea, esofagul sau nervul recurent);  T4b = invasive tumor: - prevertebral fascia - or includes the carotid artery - or the mediastinal vessels; All anaplastic carcinomas are considered T4; T4a = anaplastic intrathyroidal carcinoma T4b = extrathyroid anaplastic carcinoma  N = regional nodes N0 = no regional nodes N1 = with regional lymph node metastases N1a = homolateral lymph node metastases N1b = bilateral or contralateral cervical lymph node metastases  M = distant metastases Mx = distant metastases cannot be determined M0 = without the presence of distant metastases M1 = distant metastases present  Grouping by stages Staging is recommended to be performed separately for papillary, follicular, medullary and undifferentiated carcinomas:  Papillary or follicular At ages under 45 Std. I - any T any N M0 Std. II - any T any N M1 At ages 45 and over Std. I - T 1 N0 M0 Std. II - T 2 N0 M0 Std. III -T 3 N0 M0 T 4 N0 M0 Std. IV - any T any N M1  Medulary Std. I - T 1 N0 M0 Std. II - T 2 N0 M0 T 3 N0 M0 T 4 N0 M0 Std. III - any T N1 M0 Std. IV - any T any N M1  Nediferenţiate Std. IV - any T any N any M (all cases are considered stage IV) after Sobin L.H. TNM Classification of malignant tumors – fifth edition 1997, Wiley-Liss, New York: 47-51  Histopatology. We meet 4 main types: -papillary, - follicular, - medullary, - anaplastic;. Over 90% of cases are papillary and follicular carcinomas..Medullary carcinomas represent only 5-10% of all thyroid neoplasms.. Evolution and complications Dissemination is carried out by lymphatic and hematogenous means. The most frequently affected nodes are the jugular nodes. Undifferentiated carcinomas spread most frequently by hematogenous route, especially in the lung and bones, less often in the liver, kidney, and brain.  Prognostic factors The main factors that negatively affect the prognosis for differentiated cancers are: - dimensions of the thyroid nodule - over 5 cm; - extension of the tumor through the thyroid capsule; - age - over 40 years; - the presence of symptoms and metastases; - histopathological type (anaplastic carcinomas have a very low survival rate).  Tratament Available treatments are: -surgery, -external radiotherapy, -metabolic radiotherapy, Papillary and follicular thyroid cancers in stages I and II benefit from: total thyroidectomy or lobectomy- followed by I131 administration.  In stage III the following is practiced: total thyroidectomy with cervical lymphadenectomy+ followed by administration of I131 or only external irradiation, if the tumor does not show uptake of I131.  In stage IV, -administer I131, if there is capture -external radiotherapy in those who do not respond to I131 administration. In medullary thyroid cancers, total thyroidectomy with cervical lymphadenectomy is performed.  Anaplastic thyroid cancers benefit from: - surgical treatment, -radiotherapy -and chemotherapy with Doxorubicin and Cisplatin. After radical surgical interventions, hypothyroidism sets in, which becomes evident after three to four weeks. Hormone replacement therapy consists in the administration of thyroid extract or thyroxine. Result The prognosis of thyroid tumors depends on the histopathological type, the age of the patient and the stage of the disease. Young ages are associated with a favorable evolution. They have the best prognosis: -differentiated forms, -papillary adenocarcinomas, - follicular carcinomas with lower survival - 75% at 5 years.  Undifferentiated carcinomas have the worst prognosis, the 1-year survival being approx. 20%.