Fig. 1
ETV6 fluorescence in situ hybridization (FISH). (A) ETV6 FISH showing 1 fused (yellow) and 1 split (red and green) signal indicative of a translocation. (B) Mimic mammary analogue secretory carcinoma showing a negative ETV6 FISH as evident by 2 intact signals in each cell.
Fig. 2Usual mammary analogue secretory carcinoma (MASC) morphologic features. (A) Gross photograph showing a lobulated and whitish-yellow colored tumor of the parotid gland. (B) MASC showing microcystic and papillary-cystic growth pattern. (C, D) Admixture of variable cell types with eosinophilic or vacuolated cytoplasm and intraluminal secretory material.
Fig. 3Unusual histologic features of mammary analogue secretory carcinoma. (A) One prominent macrocyst with intraluminal papillary proliferation. (B) Variable-sized cysts among the fibrous stroma and mucinous metaplasia.
Fig. 4Unusual histologic features of mammary analogue secretory carcinoma. (A) Microcystic growth pattern showing dedifferentiation with transitional area. (B) Solid growth pattern with high-grade cellular features.
Fig. 5Four examples of histologic features of mimic mammary analogue secretory carcinoma (A and B; C and D; E; F). (A) Macrocyst with extensive papillary proliferation. (B) Papillae showing an eosinophilic but cuboidal to columnar appearance. (C) Macrocyst showing intraluminal papillary proliferation with large papillae. (D) Papillae showing clear to oncocytic cytoplasm. (E) Solid nests with clear to reticular cytoplasm surrounded by very thin fibrovascular septa. (F) Glandular growth pattern in prominent sclerosing stroma.
Fig. 6S100 protein immunohistochemistry. (A) Mammary analogue secretory carcinoma (MASC) with strong S100 protein immunostaining. (B) Mimic MASC with strong S100 protein immunostaining.
Table 1.Antibodies used for immunohistochemical study
Primary antibodies |
Source |
Dilution |
Clone |
S100 protein |
Zymed |
1 : 200 |
Mouse monoclonal |
ER |
Novo |
1 : 50 |
Mouse monoclonal |
PR |
Novo |
1 : 200 |
Mouse monoclonal |
GCDFP-15 |
Neomarkers |
1 : 50 |
Mouse monoclonal |
DOG1 |
Spring Science |
1 : 200 |
Rabbit polyclonal |
Table 2.Clinicopathologic features of MASCs, mimic MASCs, and conventional AciCCs
Feature |
|
MASC (n = 13) |
Mimic MASC (n = 10) |
Conventional AciCC (n = 15) |
Sex |
Male |
8 |
8 |
3 |
|
Female |
5 |
2 |
12 |
Average age (yr) |
|
46.4 (17-76) |
46.3 (15-75) |
44.1 (24-65) |
Site |
Parotid gland |
11 |
6 |
13 |
|
Non-parotid gland |
2 |
4 |
2 |
Tumor size (cm) |
|
1.77 (0.7-2.5) |
2.34 (1.0-3.3) |
2.57 (1.0-5.5) |
Pathologic T stage |
T1 |
6 |
2 |
5 |
|
T2 |
3 |
2 |
9 |
|
T3 |
4 |
6 |
1 |
Lymph node metastasis |
|
0 |
2 |
0 |
Treatment |
Surgery |
11 |
7 |
13 |
|
Surgery+radiation |
2 |
3 |
2 |
Follow-up |
Died of disease |
0 |
0 |
0 |
|
Local recurrence |
3 |
0 |
1 |
|
Metastasis |
0 |
2 |
0 |
|
No evidence of disease |
6 |
7 |
11 |
|
Loss |
4 |
1 |
3 |
Table 3.Immunohistochemical features of MASCs, mimic MASCs, and conventional AciCCs
|
S100 protein |
GCDFP-15 |
ER |
PR |
DOG1 |
MASC |
13/13 |
2/13 |
0/13 |
0/13 |
1/13 |
Mimic MASC |
3/10 |
3/10 |
0/10 |
0/13 |
0/10 |
Conventional AciCC |
0/6 |
0/6 |
0/6 |
0/6 |
3/6 |