Abstract：
OBJECTIVE: Low-grade non-intestinal-type sinonasal adenocarcinoma (LGSNAC) is a rare heterogeneous and poorly characterised group of tumours, distinct from intestinal- and salivary-type neoplasms. Therefore, further characterisation is needed for clearer biological understanding and classification.
RESULTS: Clinical, histological and molecular characterisation of four cases of biphasic, low-grade adenocarcinomas of the sinonasal tract was performed. All patients were male, aged between 48 and 78 years, who presented with polypoid masses in the nasal cavity. Microscopically, virtually all tumours were dominated by tubulo-glandular biphasic patterns, microcystic, focal (micro)papillary, oncocytic or basaloid features. Immunohistochemical staining confirmed biphasic differentiation with an outer layer of myoepithelial cells. Molecular profiling revealed HRAS (p.G13R, p.Q61R) mutations, and concomitant AKT1 (p.E17K, p.Q79R) mutations in two cases. Two cases showed potential in-situ/precursor lesions adjacent to the tumour. Follow-up periods ranged from 1 to 30 months, with one case relapsing locally after 12 and > 20 years.
CONCLUSIONS: This study further corroborates a distinct biphasic low-grade neoplasm of the sinonasal tract with seromucinous differentiation. Although morphological and molecular features overlap with salivary gland epithelial-myoepithelial carcinoma, several arguments favour categorising these tumours within the spectrum of LGSNAC.
RESULTS: Clinical, histological and molecular characterisation of four cases of biphasic, low-grade adenocarcinomas of the sinonasal tract was performed. All patients were male, aged between 48 and 78 years, who presented with polypoid masses in the nasal cavity. Microscopically, virtually all tumours were dominated by tubulo-glandular biphasic patterns, microcystic, focal (micro)papillary, oncocytic or basaloid features. Immunohistochemical staining confirmed biphasic differentiation with an outer layer of myoepithelial cells. Molecular profiling revealed HRAS (p.G13R, p.Q61R) mutations, and concomitant AKT1 (p.E17K, p.Q79R) mutations in two cases. Two cases showed potential in-situ/precursor lesions adjacent to the tumour. Follow-up periods ranged from 1 to 30 months, with one case relapsing locally after 12 and > 20 years.
CONCLUSIONS: This study further corroborates a distinct biphasic low-grade neoplasm of the sinonasal tract with seromucinous differentiation. Although morphological and molecular features overlap with salivary gland epithelial-myoepithelial carcinoma, several arguments favour categorising these tumours within the spectrum of LGSNAC.
摘要：
目的：低级别非肠型鼻窦腺癌（LGSNAC）是一种罕见的异质性肿瘤，有别于肠道和唾液型肿瘤。因此,需要进一步表征，以更清晰的生物学理解和分类。
结果：临床，四例双相的组织学和分子特征，进行了鼻窦道低度腺癌.所有患者均为男性,年龄在48至78岁之间，在鼻腔出现息肉样肿块。微观上,几乎所有肿瘤都以肾小管-腺双相模式为主，微囊,局灶性（微）乳头状，嗜酸细胞或基底细胞状特征。免疫组织化学染色证实了具有肌上皮细胞外层的双相分化。分子谱分析显示HRAS（p。G13R,p.Q61R）突变，和伴随AKT1（p。E17K,p.Q79R)突变2例。2例显示与肿瘤相邻的潜在原位/前体病变。随访期为1至30个月,其中一例在12年和>20年后局部复发。
结论：本研究进一步证实了一个明显的具有浆膜粘质分化的鼻窦道双相低度肿瘤。尽管形态学和分子特征与唾液腺上皮-肌上皮癌重叠，一些论点支持将这些肿瘤分类在LGSNAC的范围内。
结果：临床，四例双相的组织学和分子特征，进行了鼻窦道低度腺癌.所有患者均为男性,年龄在48至78岁之间，在鼻腔出现息肉样肿块。微观上,几乎所有肿瘤都以肾小管-腺双相模式为主，微囊,局灶性（微）乳头状，嗜酸细胞或基底细胞状特征。免疫组织化学染色证实了具有肌上皮细胞外层的双相分化。分子谱分析显示HRAS（p。G13R,p.Q61R）突变，和伴随AKT1（p。E17K,p.Q79R)突变2例。2例显示与肿瘤相邻的潜在原位/前体病变。随访期为1至30个月,其中一例在12年和>20年后局部复发。
结论：本研究进一步证实了一个明显的具有浆膜粘质分化的鼻窦道双相低度肿瘤。尽管形态学和分子特征与唾液腺上皮-肌上皮癌重叠，一些论点支持将这些肿瘤分类在LGSNAC的范围内。
