[A Rare Case of Pulmonary Epithelial-myoepithelial Carcinoma: Case Report and Literature Review]

背景与目的

肺上皮-肌上皮癌（pulmonary epithelial-myoepithelial carcinoma, P-EMC）是一种十分罕见的涎腺型肺肿瘤，尚无标准治疗方案，本文拟分析肺上皮-肌上皮癌的临床特点，探讨肺上皮-肌上皮癌的诊疗方案。

方法

分析1例肺上皮-肌上皮癌患者的临床资料并回顾其他相关临床文献。

结果

上皮细胞免疫组化表达细胞角蛋白，肌上皮细胞免疫组化表达SMA及S-100，二代基因测序以HRAS基因突变为主，PD-L1蛋白为阴性。

结论

肺上皮-肌上皮癌大多预后良好，诊断以镜检及免疫组化为主，治疗以手术切除为主，放化疗效果尚不明确。

Prominent entrapment of respiratory epithelium in primary and metastatic intrapulmonary non-epithelial neoplasms: a frequent morphological pattern closely mimicking adenofibroma and other biphasic pulmonary lesions

As one of the most common target organs for hematogenous spread from diverse cancers, biopsy interpretation of lung tumors is complicated by the challenging question of primary versus metastatic and by frequent entrapment of native respiratory glands. Nevertheless, the literature dealing with this issue is surprisingly sparse and no single study has been devoted to this topic. We reviewed 47 surgical lung specimens of non-epithelial neoplasms (38 metastases, mainly from sarcomas and 9 primary lesions) for frequency and pattern of intralesional epithelial entrapment. Respiratory epithelium entrapment was noted in 23/47 (49%) cases (diffuse in 15 and peripheral in 8). Entrapped glands frequently showed prominent regenerative and reactive changes mimicking neoplastic glands. Based on cellularity of the mesenchymal component and the extent, distribution and shape of entrapped respiratory glands, four morphological patterns were recognized: paucicellular sclerosing low-grade neoplasms containing leaflet-like glands indistinguishable from adenofibroma and fibroepithelial hamartomas (n = 11), and biphasic cellular lesions mimicking adenomyoepithelioma (n = 1), biphasic synovial sarcoma (n = 2), and pleuropulmonary blastoma (n = 1). Only a single genuine pulmonary adenofibroma was identified. This study highlights frequent respiratory epithelium entrapment in diverse non-epithelial lung tumors, both primary and metastatic. Recognition of this finding and use of adjunct IHC combined with clinical history should help to avoid misinterpretation as primary pulmonary biphasic neoplasm or as harmless adenofibroma. The vast majority of morphologically defined lung adenofibromas represent adenofibroma-like variants of histogenetically diverse entities so that a diagnosis of adenofibroma should be rendered only very restrictively and then as a diagnosis by exclusion.

Updates on Immunohistochemical and Molecular Markers in Selected Head and Neck Diagnostic Problems

CONTEXT

- The head and neck regions have complex anatomic structures. They are not exempted from the rare occurrences of highly unusual, diagnostically challenging malignant neoplasms and mimickers.

OBJECTIVE

- To review and update the utility of immunohistochemistry and molecular biomarkers and to pursue diagnostic accuracy on selected rare neoplasms, especially some poorly differentiated malignancies.

DATA SOURCES

- Personal experience and information from the literature.

CONCLUSIONS

- Head and neck tumors include neoplasms originating from heterogeneous tissue. Using the selected clinical cases, this review illustrates a continuous development of emerging molecular-genetic techniques to assist in the interpretation of uncommon, often poorly differentiated, highly malignant neoplasms. The diagnostic results are appropriately transmitted to the oncologists, radiation oncologists, and surgeons to create a coordinated plan of care for patients with these unusual disorders affecting the head and neck.