Objective: The purpose of this study was to clarify the diagnostic significance of cytoplasmic lipid accumulation (CLIA) in the cribriform variant of papillary thyroid carcinoma (CV-PTC).
Methods: We performed a histological, immunohistochemical, and cytological examination of 35 CV-PTC cases at the Kuma Hospital. CLIA was defined as bubble-like multivacuolation in cytoplasm with distinct cell border. We also examined 100 conventional PTC (con-PTC) cases as controls.
Results: Histological analysis showed the presence of carcinoma cells with CLIA in 60.0% of CV-PTC and 5.0% of con-PTC cases. The vacuoles tended to distribute in the subnuclear portion of carcinoma cells showing papillary growth. They were positive for oil red O staining and adipophilin. The carcinoma cells without the vacuoles showed a subnuclear dot-like expression for adipophilin in CV-PTC cases, but not in the con-PTC cases. Cytological analysis showed CLIA in 17 (54.8%) of the 31 CV-PTC cases, but not in the con-PTC cases.
Conclusion: This is the first study to report the presence of carcinoma cells with CLIA in CV-PTC. The subnuclear dot-like expression of adipophilin may be characteristic of CV-PTC. These findings might be related to degenerative changes occurring in CV-PTC.
Keywords: Adipophilin; Cribriform variant; Foamy cytoplasm; Papillary thyroid carcinoma; Subnuclear lipid accumulation.
© 2017 The Author(s) Published by S. Karger AG, Basel.