Abstract：
BACKGROUND: Adenoid cystic carcinoma is a rare subtype of triple-negative breast carcinoma. These low-grade tumours, which are treated by simple mastectomy and have an excellent prognosis compared to other triple-negative breast carcinomas. Solid-variant adenoid cystic carcinomas have basaloid features and are difficult to distinguish morphologically from other triple-negative breast cancers. Breast adenoid cystic carcinoma exhibits MYB protein overexpression, which can be detected by immunohistochemistry (IHC).
OBJECTIVE: We compared the IHC expression of MYB in solid-variant adenoid cystic carcinoma with that in other triple-negative breast cancers.
METHODS: We conducted IHC staining of 210 samples of triple-negative breast cancers, including solid-variant adenoid cystic carcinoma (n = 17), metaplastic breast carcinoma (n = 44), basaloid triple-negative breast cancer (n = 21), and other triple-negative invasive ductal carcinoma (n = 128). We classified nuclear staining of MYB as diffuse/strong (3+), focal moderate (2+), focal weak (1+), or none (0).
RESULTS: All 17 solid/basaloid adenoid cystic carcinoma cases exhibited 3+ MYB expression. Of the 21 solid/basaloid triple-negative breast cancers, one (5%) had 2+ expression, seven (33%) 1+ expression, and 13 (62%) 0 expression. Of the 44 metaplastic carcinoma cases, 39 cases (89%) had no (0) staining, and the other five cases had focal weak (1+) or moderate (2+) staining. Among the 128 triple-negative invasive ductal carcinoma cases, 92 cases (72%) had no (0) staining, 36 cases (28%) exhibited focal weak (1+) or moderate (2+) staining.
CONCLUSIONS: Our study revealed diffuse/strong MYB staining (3+) only in solid/basaloid adenoid cystic carcinomas. Thus, we recommend routine MYB IHC staining in triple-negative breast carcinoma with solid/basaloid morphology to improve diagnostic accuracy.
OBJECTIVE: We compared the IHC expression of MYB in solid-variant adenoid cystic carcinoma with that in other triple-negative breast cancers.
METHODS: We conducted IHC staining of 210 samples of triple-negative breast cancers, including solid-variant adenoid cystic carcinoma (n = 17), metaplastic breast carcinoma (n = 44), basaloid triple-negative breast cancer (n = 21), and other triple-negative invasive ductal carcinoma (n = 128). We classified nuclear staining of MYB as diffuse/strong (3+), focal moderate (2+), focal weak (1+), or none (0).
RESULTS: All 17 solid/basaloid adenoid cystic carcinoma cases exhibited 3+ MYB expression. Of the 21 solid/basaloid triple-negative breast cancers, one (5%) had 2+ expression, seven (33%) 1+ expression, and 13 (62%) 0 expression. Of the 44 metaplastic carcinoma cases, 39 cases (89%) had no (0) staining, and the other five cases had focal weak (1+) or moderate (2+) staining. Among the 128 triple-negative invasive ductal carcinoma cases, 92 cases (72%) had no (0) staining, 36 cases (28%) exhibited focal weak (1+) or moderate (2+) staining.
CONCLUSIONS: Our study revealed diffuse/strong MYB staining (3+) only in solid/basaloid adenoid cystic carcinomas. Thus, we recommend routine MYB IHC staining in triple-negative breast carcinoma with solid/basaloid morphology to improve diagnostic accuracy.
摘要：
背景：腺样囊性癌是三阴性乳腺癌的一种罕见亚型。这些低级别的肿瘤，与其他三阴性乳腺癌相比，采用简单的乳房切除术治疗，预后良好。实体变异型腺样囊性癌具有基底细胞样特征，难以从形态上与其他三阴性乳腺癌区分。乳腺腺样囊性癌表现出MYB蛋白过表达，可以通过免疫组织化学（IHC）检测。
目的：我们比较了实体变异型腺样囊性癌与其他三阴性乳腺癌中MYB的IHC表达。
方法：我们对210例三阴性乳腺癌样本进行了IHC染色，包括实性变异型腺样囊性癌（n=17），化生性乳腺癌（n=44），基底细胞样三阴性乳腺癌（n=21），和其他三阴性浸润性导管癌（n=128）。我们将MYB的核染色分类为弥漫性/强（3+），局灶性中度(2+)，局灶弱（1+），或无(0)。
结果：17例实性/基底样腺样囊性癌均有3+MYB表达。在21种实体/基底细胞样三阴性乳腺癌中，一个（5%）有2+表达，七个（33%）1+表达，表达13(62%)0。44例化生性癌,39例（89%）无（0）染色，其余5例有局灶性弱(1+)或中度(2+)染色。在128例三阴性浸润性导管癌患者中，92例（72%）无（0）染色，36例（28％）显示局灶性弱（1）或中度（2）染色。
结论：我们的研究仅在实性/基底样腺样囊性癌中显示弥漫性/强MYB染色(3+)。因此，我们建议对具有实性/基底样形态的三阴性乳腺癌进行常规MYBIHC染色,以提高诊断准确性.
目的：我们比较了实体变异型腺样囊性癌与其他三阴性乳腺癌中MYB的IHC表达。
方法：我们对210例三阴性乳腺癌样本进行了IHC染色，包括实性变异型腺样囊性癌（n=17），化生性乳腺癌（n=44），基底细胞样三阴性乳腺癌（n=21），和其他三阴性浸润性导管癌（n=128）。我们将MYB的核染色分类为弥漫性/强（3+），局灶性中度(2+)，局灶弱（1+），或无(0)。
结果：17例实性/基底样腺样囊性癌均有3+MYB表达。在21种实体/基底细胞样三阴性乳腺癌中，一个（5%）有2+表达，七个（33%）1+表达，表达13(62%)0。44例化生性癌,39例（89%）无（0）染色，其余5例有局灶性弱(1+)或中度(2+)染色。在128例三阴性浸润性导管癌患者中，92例（72%）无（0）染色，36例（28％）显示局灶性弱（1）或中度（2）染色。
结论：我们的研究仅在实性/基底样腺样囊性癌中显示弥漫性/强MYB染色(3+)。因此，我们建议对具有实性/基底样形态的三阴性乳腺癌进行常规MYBIHC染色,以提高诊断准确性.
