微分泌型腺癌(MSA)是最近描述的唾液腺肿瘤,具有特征性的组织学和免疫表型特征,并且复发性MEF2C-SS18融合。因为只发表了六例MSA,其完整的临床病理谱尚不清楚,其生物学行为尚未被记录。这里,我们介绍了24例MSA病例的更新和扩展经验。所有MSA病例均来自作者的档案。S100、SOX10、p63、p40、SMA、Calponin,并进行了乳房珠蛋白。通过靶向RNA测序进行分子分析,SS18打破荧光原位杂交,和/或用于MEF2C-SS18融合的逆转录酶聚合酶链反应。从病历中获得临床随访。共收集24例MSA病例,13名女性和11名男性,17至83岁(平均49.5岁)。绝大多数(24个中的23个)出现在口腔中,腭(n=14)和颊粘膜(n=6)是最常见的亚位点。肿瘤表现出一致的组织学特征,包括:(1)微囊小管,(2)扁平插层导管样细胞,(3)单调的椭圆形超色核,(4)丰富的嗜碱性管腔分泌物,(5)纤维黏液样基质,和(6)带有细微渗透的边界。肿瘤对S100非常一致地呈阳性(24个中的24个),P63(24of24),和SOX10(14个中的14个),p40为阴性(21个中的0个),钙蛋白(0/12)和乳腺球蛋白(0/16),而SMA(20个中的4个)是可变的。24例中有21例证实了MEF2C-SS18融合;其余3例RNA不足,SS18分解FISH为阳性。17例病例有治疗信息,所有这些都只能通过手术进行。在14例经随访(1-216个月,mean30),无复发或转移。MSA是一种独特的唾液腺肿瘤,临床上非常一致,组织学,免疫表型,和遗传特征通常在单独手术后表现为惰性。这些观察巩固了MSA作为一种独特的,低级别唾液腺癌,值得纳入WHO头颈部肿瘤分类的下一个版本。
Microsecretory adenocarcinoma (MSA) is a recently described salivary gland tumor with a characteristic histologic and immunophenotypic profile and recurrent MEF2C-SS18 fusions. Because only six cases of MSA have been published, its complete clinicopathologic spectrum is unclear, and its biologic behavior has not been documented. Here, we present an updated and expanded experience of 24 MSA cases. All cases of MSA were obtained from the authors\' files. Immunohistochemistry for S100, SOX10, p63, p40, SMA, calponin, and mammaglobin was performed. Molecular analysis was performed by targeted RNA sequencing, SS18 break apart fluorescence in situ hybridization, and/or reverse transcriptase polymerase chain reaction for MEF2C-SS18 fusion. Clinical follow-up was obtained from medical records. A total of 24 MSA cases were collected, from 13 women and 11 men, ranging from 17 to 83 years (mean 49.5 years). The vast majority (23 of 24) arose in the oral cavity, with the palate (n = 14) and buccal mucosa (n = 6) as the most frequent subsites. Tumors showed consistent histologic features including: (1) microcystic tubules, (2) flattened intercalated duct-like cells, (3) monotonous oval hyperchromatic nuclei, (4) abundant basophilic luminal secretions, (5) fibromyxoid stroma, and (6) circumscribed borders with subtle infiltration. The tumors were very consistently positive for S100 (24 of 24), p63 (24 of 24), and SOX10 (14 of 14) and negative for p40 (0 of 21), calponin (0 of 12) and mammaglobin (0 of 16), while SMA (4 of 20) was variable. MEF2C-SS18 fusion was demonstrated in 21 of 24 cases; in the remaining 3 cases with insufficient RNA, SS18 break apart FISH was positive. Treatment information was available in 17 cases, all of which were managed with surgery only. In 14 cases with follow-up (1-216 months, mean 30), no cases recurred or metastasized. MSA is a distinct salivary gland neoplasm with remarkably consistent clinical, histologic, immunophenotypic, and genetic features that generally behaves in an indolent manner following surgery alone. These observations solidify MSA as a unique, low-grade salivary gland carcinoma that warrants inclusion in the next version of the WHO classification of head and neck tumors.