透明细胞腺瘤是一种罕见的乳腺良性肿瘤,其起源和发病机制存在争议。我们经历了一例乳腺透明细胞腺瘤,其策划者如转录共激活因子2(MAML2)基因重排。患者在左乳乳晕中发现无痛肿块,质地坚硬,无乳头溢液。微观上,肿瘤是囊实性的,局部排列在腺体结构中,被单个立方体细胞覆盖;它由透明细胞组成,表皮样细胞,和基底细胞;没有坏死或有丝分裂图。免疫组织化学染色显示肿瘤细胞阳性表达低分子细胞角蛋白7、低分子细胞角蛋白(Cam5.2)、高分子细胞角蛋白5/6,细胞角蛋白14,CD117和p63;并且不表达钙蛋白,和平滑肌肌球蛋白重链。立方体细胞对SOX10呈阳性,但对p63呈阴性。此外,高碘酸-希夫反应在肿瘤胞浆内呈紫红色颗粒,但是阿尔辛蓝染色显示细胞质中没有蓝色粘液。用荧光原位杂交法检测MAML2基因的分裂信号。细微的组织学和免疫表型差异可能有助于将乳腺透明细胞瘤与常见的乳腺肿瘤区分开来。此外,MAML2基因重排可能是乳腺透明细胞瘤的分子遗传学特征。
Clear cell hidradenoma is a rare benign tumor of the breast, its origin and pathogenesis are controversial. We have experienced a case of breast clear cell hidradenoma with mastermind like transcriptional coactivator 2 (MAML2) gene rearrangement. The patient found a painless mass with a hard texture in the left breast areola without nipple discharge. Microscopically, the tumor was cystic and solid, locally arranged in a glandular structure, covered by single cuboidal cells; it was composed of clear cells, epidermoid cells, and basaloid cells; there were no necrosis or mitotic figures. Immunohistochemical staining showed that the tumor cells positively expressed low-molecular cytokeratin 7, low-molecular cytokeratins (Cam5.2), high-molecular cytokeratin 5/6, cytokeratin 14,
CD117, and p63; and did not express calponin, and smooth muscle myosin heavy chain. The cuboidal cells were positive for SOX10 but negative for p63. Additionally, periodic acid-Schiff reaction showed purple-red granules in the tumor cytoplasm, but Alcian blue staining showed no blue mucus in the cytoplasm. The split signals of MAML2 gene were detected by fluorescence in situ hybridization. Subtle histological and immunophenotypical differences may help to distinguish breast clear cell hidradenoma from common breast tumors. Furthermore, the MAML2 gene rearrangement may be a molecular genetic characteristic of breast clear cell hidradenoma.