Fig. 1: Histopathological features of secretory carcinoma.

Tumors frequently show papillary cystic (a) and microcystic (b) growth architectures. The tumor cells show low-grade uniform nuclei, occasional small nucleoli, and pinkish bubbly cytoplasm (c). Mucin-like and/or eosinophilic secretions are easily detected in tumors with microcystic growth patterns (b, d). The tumors showed expression of S100 (e) and mammaglobin (f) and no expression of DOG1 (g). An ETV6 break-apart FISH assay showed a split of one red signal and one green signal per nucleus, indicative of ETV6 translocation (H: yellow arrow) with a fusion signal (H: gray arrow). The images in A through G were captured at ×100 and ×400 magnification.