PMC6939431_01
(a) H&E (100x). Characteristic cystic, papillary and cribriform architecture seen in mammary analogue secretory carcinoma (MASC). (b) H&E (400x) Characteristic cytologic features of MASC:cuboidal cells with abundant eosinophilic vacuolated cytoplasm, bland round to oval nuclei with inconspicuous nucleoli.
CRIPA2019-7468691.001.jpg
PMC6939431_01_CRIPA2019-7468691.001.jpg
fig1
The tumor showed macrocystic and microcystic architecture as well as solid and papillary areas (Figure 1(a)). The nuclei were round to oval, with homogenous chromatin and subtle nucleoli (Figure 1(b)).
(a) Mammaglobin (Left:40x, Right:400x). (b) S100 (Left:40x, Right:400x).
CRIPA2019-7468691.002.jpg
PMC6939431_01_CRIPA2019-7468691.002.jpg
fig2
The lesional cells were strongly and diffusely positive for mammaglobin (Figure 2(a)) and S100 (Figure 2(b)), as well as vimentin, CK7, CK19, BRST2, Cam5.2, and 34betaE12.
(a) Cell without ETV6 break-apart signal. (b) Probe map of the FISH kit used.
CRIPA2019-7468691.003.jpg
PMC6939431_01_CRIPA2019-7468691.003.jpg
fig3
Lumina lined by short microvilli. Small dense granules (arrow) but no zymogen granules.
CRIPA2019-7468691.004.jpg
PMC6939431_01_CRIPA2019-7468691.004.jpg
fig4
Electron microscopy showed epithelial cells forming nests, with lumina lined by small microvilli (Figure 4). A few cells contained small intracytoplasmic, homogenous electron dense granules (Figure 4), however, diagnostic zymogen granules were not identified.
Nests of cells with slit-like luminal formation. Areas of prominent rough endoplasmic reticulum are seen (arrow).
CRIPA2019-7468691.005.jpg
PMC6939431_01_CRIPA2019-7468691.005.jpg
fig5
There was focally an abundance of rough endoplasmic reticulum (Figures 5 and 6).
Nests of cells showing focal lipid, lysosomes (arrow) and stacks of rough endoplasmic reticulum.
CRIPA2019-7468691.006.jpg
PMC6939431_01_CRIPA2019-7468691.006.jpg
fig6
There was focally an abundance of rough endoplasmic reticulum (Figures 5 and 6).