Three dogs were investigated for chronic unilateral nasal discharge. In all cases CT imaging showed an intranasal mass causing turbinate lysis and no evidence of metastasis. Cytology in cases 1 (a 14-year-old neutered male crossbreed dog) and 2 (a five-year-old neutered male German Shepherd dog) demonstrated a pleomorphic cell population with variable intracellular pigment suspicious of melanocytic neoplasia. Histopathology with immunohistochemistry (Melan-A and vimentin, plus PNL-2 in one case) confirmed the diagnosis of melanoma in all dogs. All dogs were treated with megavoltage radiotherapy using linear accelerators. Cases 1 and 3 (a nine-year-old neutered female beagle dog) received a hypofractionated (4 × 8 Gy) protocol and case 2 received a definitive (12 × 4 Gy) protocol. Complete remission was demonstrated on repeat CT scan five months after diagnosis in case 1 and seven months in case 2. Stable disease was documented on CT at four months for case 3; however, clinical signs in this dog remained controlled for 10 months in total. Case 1 died of unrelated causes five months after diagnosis, case 2 was euthanased due to the development of seizures 13 months after diagnosis, and case 3 was lost to follow-up 12 months after diagnosis. Melanoma should be considered as a rare differential diagnosis for primary nasal neoplasia in the dog and radiation therapy can be used as effective local therapy.

研究了三只狗的慢性单侧鼻涕。在所有情况下，CT成像均显示鼻内肿块引起鼻甲溶解，无转移迹象。病例1（一只14岁绝育的雄性杂种狗）和病例2（一只5岁绝育的雄性德国牧羊犬）的细胞学检查显示多形细胞群，细胞内色素可变，可疑为黑素细胞瘤形成。免疫组织化学的组织病理学检查（Melan-A和波形蛋白，一例加上PNL-2）证实了所有狗的黑色素瘤的诊断。使用线性加速器对所有的狗进行兆伏放疗。案例1和3（一只九岁的绝育雌性比格犬）接受了普通分割（4×8 Gy）协议，案例2获得了确定性（12×4 Gy）协议。病例1诊断后5个月，病例2重复7个月，重复CT扫描证实完全缓解。但是，这只狗的临床体征总共可以控制10个月。病例1在诊断后5个月死于无关原因，病例2在诊断后13个月因癫痫发作而被安乐死，病例3在诊断后12个月失去了随访。黑色素瘤应被认为是犬原发性鼻肿瘤的罕见鉴别诊断，放射治疗可作为有效的局部治疗。病例1在诊断后5个月死于无关原因，病例2在诊断后13个月因癫痫发作而被安乐死，病例3在诊断后12个月失去了随访。黑色素瘤应被认为是犬原发性鼻肿瘤的罕见鉴别诊断，放射治疗可作为有效的局部治疗。病例1在诊断后5个月死于无关原因，病例2在诊断后13个月因癫痫发作而被安乐死，病例3在诊断后12个月失去了随访。黑色素瘤应被认为是犬原发性鼻肿瘤的罕见鉴别诊断，放射治疗可作为有效的局部治疗。