Tall Cell Variant of Papillary Carcinoma and Papillary Thyroid Carcinoma with Tall Cell Features Are Often Under-Diagnosed: A Retrospective Analysis of Cases Referred for Second Opinion for Clinical Management
KT Montone, ZW Baloch, K Shafique, S Mandel, A Chalian, G Weinstein, VA LiVolsi. University of Pennsylvania, Philadelphia, PA
Background: In 1976, Hawk and Hazard described a variant of papillary thyroid carcinoma (PTC) characterized by cells with classic PTC nuclei and eosinophilic cytoplasm that were twice as tall as they were wide. This “tall cell” variant (TCV) of PTC was shown to behave in a more aggressive fashion than classic PTC. Several studies have shown TCV to be an aggressive form of PTC which has a 25% mortality rate at 10 years. Since the treatment of TCV and PTC with tall cell features (TCF) may differ from the treatment of classic PTC, the recognition of TCs in PTC is important for treatment decisions. We observed a recent lack of recognition of TC changes in patients with PTCs referred to our institution for further clinical management and examined the potential under-diagnosis of TCV and PTC with TCF in our referral patient population.
Design: A retrospective analysis of microscopic slides referred to our institution over a 5 year period (2003-2008) forms the basis of this report. Patients diagnosed with PTC and referred to our institution for additional clinical management for primary or recurrent disease were studied. In a percentage of these patients our pathology group made a diagnosis of TCV or PTC with TCF on referred slides. The pathology reports from the referring institutions were reviewed to determine the original diagnoses rendered on the slides.
Results: A TC was defined 2-3 times tall as wide and having classic PTC nuclei. TCV was diagnosed when 50% or greater TCs were present while PTC with TCF was diagnosed when <50% of the tumor contained TCs. We analyzed 225 PTC specimens referred for second opinion for clinical care and identified 40 patients (18%) in which the diagnosis of TCV (16) or PTC with TCF (24) was rendered on our review. The diagnoses rendered at the referring institution revealed TCV or PTC with TCF in only 6/40 patients (14%). In the remaining 86% of patients, no mention of “tall cell” was present in the report. 26/40 patients subsequently developed nodal metastases and 2/40 patients developed distant metastases to lung and brain at 12 years and <1 year after initial diagnosis respectively. Neither of these two cases mentioned "tall cells" in the original surgical pathology report.
Conclusions: Despite being a recognized variant of PTC for over 30 years, TCV is often under-diagnosed. This may lead to under treatment of this potentially aggressive variant of PTC.
Category: Head & Neck
Wednesday, March 24, 2010 9:30 AM
Poster Session V # 170, Wednesday Morning