RESUMO
CONTEXT.: Retraction artifact, paradoxic maturation/differentiation, desmoplasia, and complex irregular growth are morphologic criteria of invasion in urothelial carcinoma. OBJECTIVE.: To describe changes mimicking invasion in noninvasive papillary urothelial carcinoma (NPUC). DESIGN.: We reviewed 159 consecutive in-house patients with NPUC for either the presence of pseudoinvasion (irregular carcinoma nests within dense hyalinized stroma in the absence of other criteria of invasion) or precursor findings (stromal hyalinization not yet associated with epithelial architectural alteration). We assessed the correlation of these findings with age, sex, evidence of peripheral vascular disease, tumor grade, tumor infarction, and tumor size. We then followed up the patients clinically for tumor recurrence or progression. RESULTS.: We identified 233 separate NPUCs (136 high grade and 97 low grade) in 125 men and 34 women. Of the 233 tumors, 26 (11.2%) had pseudoinvasion and 24 of 233 tumors (10.3%) had precursor findings. Except for complex irregular growth, no other criteria for invasion were seen. Pseudoinvasion and precursor findings were more common in men (47 of 183 [26%] versus 3 of 50 [6%]; P = .003), larger tumors (mean size, 2.6 versus 1.2 cm; P < .001), and tumors with infarction (33 of 50 [66%] versus 29 of 183 [15.8%]; P < .001). In multivariable analysis, tumor size (odds ratio, 1.49; P =.006), male sex (odds ratio, 6.48; P = .007), and the presence of infarction (odds ratio, 6.59; P < .001) were significant variables. Recurrence rates did not differ between patients with and without pseudoinvasion (31% [5 of 16] versus 42% [45 of 107], respectively; P = .41). None of the tumors with pseudoinvasion progressed to invasive carcinoma. CONCLUSIONS.: Given the correlation with size and presence of infarcted papillae, we suggest the possibility of tumor ischemia/infarction as a plausible etiology of pseudoinvasion. Awareness of this phenomenon is important for the accurate diagnosis of invasion in papillary urothelial carcinoma.
RESUMO
OBJECTIVES: The 2015 American Thyroid Association (ATA) guidelines called for significantly more selective 131I therapy in patients with low-risk differentiated thyroid cancer (DTC). We hypothesized that application of these guidelines would significantly reduce the 131I activity utilized by an academic tertiary hospital in Jordan. METHODS: All DTC patients managed at Jordan University Hospital (JUH) between 1/2009 and 6/2019 were classified according to the 2015 ATA risk category and 131I activity was assigned accordingly. The actual 131I activity administered was compared with that recommended by the 2015 ATA guidelines. RESULTS: In total, 135/182 DTC patients (74.2%) managed at JUH underwent 131I therapy. Of those, 58 (43%) had ATA low-, 58 (43%) intermediate-, and 19 (14%) high-risk disease. The low-, intermediate-, and high-risk DTC patients received an average (±SD) initial 131I activity of 3.53 ± 0.95, 4.40 ± 1.49, and 5.06 ± 2.52 GBq, respectively. Withholding 131I therapy altogether in the 2015 ATA low-risk patients would result in decreasing the 131I activity in the overall patient population by 37%. Withholding 131I therapy only in low-risk papillary thyroid microcarcinomas while administering 1.11 GBq of 131I to other low-risk patients would result in 28% reduction of 131I. CONCLUSION: This study demonstrates a significant reduction in 131I therapeutic activity that would be given to DTC patients in an academic tertiary setting in Jordan, following acceptance of the 2015 ATA recommendations. Institutions that adopted the 2015 ATA guidance should measure outcomes in comparison to their historical controls and report those findings, while long-term results of randomized controlled trials are forthcoming.
