Prognostic Impact of Focal Poorly Differentiated Areas in Follicular Differentiated Thyroid Cancer: Is It a Distinct Entity from Poorly Differentiated Thyroid Cancer?

The Long Journey towards Personalized Targeted Therapy in Poorly Differentiated Thyroid Carcinoma (PDTC): A Case Report and Systematic Review

“…Since cytological diagnosis of PDTC based on FNAC is challenging, our review has shown that some patients underwent a hemithyroidectomy or subtotal thyroidectomy with a completion thyroidectomy after histological diagnosis [ 38 , 44 , 52 , 54 , 59 , 65 , 69 , 85 , 103 , 104 , 107 , 108 , 115 , 117 ], but the majority of them were submitted to a total thyroidectomy as the initial operation [ 40 , 41 , 42 , 43 , 46 , 48 , 49 , 50 , 51 , 53 , 54 , 55 , 56 , 58 , 60 , 61 , 62 , 64 , 67 , 68 , 69 , 72 , 73 , 75 , 79 , 80 , 81 , 82 , 85 , 86 , 88 , 89 , 90 , 91 , 92 , 93 , 95 , 96 , 100 , 101 ,…”

“…Unlike in DTC [ 123 , 124 ], RAI appears to be relatively ineffective in the control of distant metastases in PDTC; thus, it is reasonable to consider the use of RAI for metastatic/advanced disease that demonstrates definite iodine uptake [ 125 , 126 ]. Likewise, most cases in our review received at least one cycle of RAI treatment, even without detectable metastatic foci [ 38 , 39 , 40 , 41 , 42 , 43 , 46 , 48 , 49 , 50 , 51 , 53 , 54 , 55 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 73 , 74 , 75 , 80 , 81 , 82 , 85 , 86 , 87 , 88 , 90 , 91 , 97 , 99 , 101 , 102 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 ...…”

“…In our case report, RAIR disease was evident after two RAI treatments. External beam radiation therapy (EBRT) is a viable option for controlling local disease in patients with PDTC and was utilized in the subset of patients with unresected, locally advanced disease or with metastatic foci such as bone lesions [ 42 , 49 , 50 , 58 , 60 , 61 , 62 , 63 , 64 , 67 , 68 , 69 , 70 , 74 , 75 , 80 , 81 , 85 , 90 , 91 , 97 , 98 , 102 , 106 , 107 , 108 , 109 , 112 , 113 , 116 ].…”

“…However, it remains debatable whether the cut-off value for the poorly differentiated area should be reported in PDTC tumors. Based on our review, several cases had a multiconstituent histology of well-differentiated (mostly PTC and FTC) with poorly differentiated areas without elaborating on their extent [ 49 , 50 , 55 , 56 , 58 , 69 , 71 , 72 , 73 , 91 , 100 , 103 , 107 , 109 , 112 , 113 ]. Interestingly, the Japanese society of thyroid surgery emphasizes that the presence of a poorly differentiated component should be acknowledged as a distinct entity from DTC, independent of its histological extent within the tumor [ 128 ].…”

Thyroid Carcinoma: A Review for 25 Years of Environmental Risk Factors Studies

“…Papillary thyroid cancer (80–85%), follicular thyroid cancer (10–15%), poorly differentiated thyroid cancer (2%), and undifferentiated (anaplastic) thyroid cancer (2%) are the four subtypes of follicular cell-derived thyroid cancers [ 9 ]. These have an excellent prognosis, except for undifferentiated thyroid cancer [ 10 ].…”