Medullary and papillary carcinoma of the thyroid gland occurring as a collision tumor with lymph node metastasis: A case report

<p>Abstract</p> <p>Introduction</p> <p>Papillary thyroid carcinoma and medullary thyroid carcinoma are two different thyroid neoplasia. The simultaneous occurrence of medullary thyroid carcinoma and papillary thyroid carcinoma as a collison tumor with metastases from both lesions in the regional lymph nodes is a rare phenomenon.</p> <p>Case presentation</p> <p>A 32-year-old Iranian man presented with a fixed anterior neck mass. Ultrasonography revealed two separate thyroid nodules as well as a suspicious neck mass that appeared to be a metastatic lesion. The results of thyroid function tests were normal, but the preoperative calcitonin serum value was elevated. Our patient underwent a total thyroidectomy with neck exploration. Two separate and ill-defined solid lesions grossly in the right lobe were noticed. Histological and immunohistochemical studies of these lesions suggested the presence of medullary thyroid carcinoma and papillary thyroid carcinoma. The lymph nodes isolated from a neck dissection specimen showed metastases from both lesions.</p> <p>Conclusions</p> <p>The concomitant occurrence of papillary thyroid carcinoma and medullary thyroid carcinoma and the exact diagnosis of this uncommon event are important. The treatment strategy should be reconsidered in such cases, and genetic screening to exclude multiple endocrine neoplasia 2 syndromes should be performed. For papillary thyroid carcinoma, radioiodine therapy and thyroid-stimulating hormone suppressive therapy are performed. However, the treatment of medullary thyroid carcinoma is mostly radical surgery with no effective adjuvant therapy.</p

Follicular thyroid carcinoma invades venous rather than lymphatic vessels

Follicular thyroid carcinoma (FTC) tends to metastasize to remote organs rather than local lymph nodes. Separation of FTC from follicular thyroid adenoma (FTA) relies on detection of vascular and/or capsular invasion. We investigated which vascular markers, CD31, CD34 and D2-40 (lymphatic vessel marker), can best evaluate vascular invasion and why FTC tends to metastasize via blood stream to remote organs. Thirty two FTCs and 34 FTAs were retrieved for evaluation. The average age of patients with FTA was 8 years younger than FTC (p = 0.02). The female to male ratio for follicular neoplasm was 25:8. The average size of FTC was larger than FTA (p = 0.003). Fourteen of 32 (44%) FTCs showed venous invasion and none showed lymphatic invasion, with positive CD31 and CD34 staining and negative D2-40 staining of the involved vessels. The average number of involved vessels was 0.88 ± 1.29 with a range from 0 to 5, and the average diameter of involved vessels was 0.068 ± 0.027 mm. None of the 34 FTAs showed vascular invasion. CD31 staining demonstrated more specific staining of vascular endothelial cells than CD34, with less background staining. We recommended using CD31 rather than CD34 and/or D2-40 in confirming/excluding vascular invasion in difficult cases. All identified FTCs with vascular invasions showed involvement of venous channels, rather than lymphatic spaces, suggesting that FTCs prefer to metastasize via veins to distant organs, instead of lymphatic vessels to local lymph nodes, which correlates with previous clinical observations

TUNEL – an efficient prognosis predictor of salivary malignancies

Biological markers are necessary for predicting prognosis of salivary malignancies and better understanding the pathogenesis of salivary cancer. We analysed terminal deoxynucleotidyl transferase (TdT)-mediated biotinylated deoxyuridine-triphosphate (dUTP)-biotin nick-end labelling (TUNEL), p53 and Ki67 expression in 66 patients with malignant salivary tumours by immonohistochemistry, and correlated the data with survival, disease-free survival, tumour grade, stage, and local and distant metastasis. TUNEL efficiently predicted poor prognosis in salivary malignancies. The 5-year (5Y) survival probability dropped significantly with the level of TUNEL staining (from 83% in negatively stained tumours to 57 and 24% in TUNEL positively stained levels 1 and 2, respectively), (P=0.042). Extensive Ki67 staining (in addition to TUNEL) reduced the 5Y-survival rate even further and addition of positively stained p53 dropped the 5Y-survival rate to 0. The correlation rates between TUNEL and Ki67 was 58% (P=0.0001), and between TUNEL and p53 it was 50% (P=0.035). Concurrently, TUNEL correlated with metastasis, extracapsular spread, grade and stage. The correlation between TUNEL, p53 and Ki67 staining and survival probabilities, and the pathological grade, stage and metastasis spread of salivary malignancies makes this a highly effective tool in patient follow-up and prognosis