Abstract:
Malignant melanoma (MM) commonly presents as a primary skin tumor and respiratory MM cases are almost all metastatic. Primary lung MM (PMML) is quite rare, especially when manifested as an endobronchial pigmented mass, its diagnosis is relatively difficult and MM has a poor prognosis. Only a few cases have been described previously and the pathologic features, clinical behavior and therapeutic options are not well established. The present study reports the case of a 72-year-old female patient with PMML who denied any history of tumors. The patient complained of chest pain and coughing for 2 weeks. Chest computed tomography (CT) revealed a mass in the right upper lobe and an enlarged mediastinal lymph node. Positron emission tomogram-CT suggested a hypermetabolic tumor. To confirm the diagnosis, the patient underwent a transbronchial forceps biopsy and endobronchial ultrasound-guided transbronchial needle aspiration, which confirmed the diagnosis of PMML. Genetic testing identified a BRAF V600E mutation, so the patient received treatment with dabrafenib plus trametinib. PMML is extremely rare and is easily misdiagnosed as lung cancer due to its nonspecific clinical manifestations and imaging features. The diagnosis of PMML remains challenging due to its morphologic and immunophenotypic variability. Targeted therapy is a good option for advanced PMML patients with BRAF V600E mutations.
摘要:
恶性黑色素瘤(MM)通常表现为原发性皮肤肿瘤,呼吸道MM病例几乎都是转移性的。原发性肺MM(PMML)相当罕见,特别是当表现为支气管内色素性肿块时,其诊断相对困难,MM预后不良。以前只描述了少数病例和病理特征,临床行为和治疗选择还没有很好地确定。本研究报告了一名72岁的PMML女性患者,该患者否认任何肿瘤史。患者主诉胸痛和咳嗽2周。胸部计算机断层扫描(CT)显示右上叶肿块和纵隔淋巴结肿大。正电子发射断层扫描-CT提示高代谢性肿瘤。为了确认诊断,患者接受了经支气管钳活检和支气管内超声引导下经支气管针吸活检,证实了PMML的诊断。基因检测发现BRAFV600E突变,因此,患者接受了dabrafenib加曲美替尼治疗。PMML极为罕见,由于其非特异性临床表现和影像学特征,易误诊为肺癌。由于其形态学和免疫表型的变异性,PMML的诊断仍然具有挑战性。靶向治疗是BRAFV600E突变的晚期PMML患者的良好选择。