Data Sheet 1_Preputial and scrotal cutaneous mast cell tumors in dogs show no evidence of inherently higher biologic malignancy.pdf

Canine genital mast cell tumors (MCTs) have been associated with a poorer prognosis; however, no larger study has focused exclusively on MCTs in this region. This study aimed to retrospectively describe the clinicopathologic aspects and outcomes of dogs with cutaneous preputial and scrotal MCTs and compare the findings to historical data from cutaneous MCTs from other locations. Medical records from 2002 to 2024 from a single institution were reviewed and 91 dogs (35 preputial, 56 scrotal) treated surgically with or without adjuvant therapy and a minimum follow-up of 6 months were included. Tumors were graded according to Patnaik (preputial: 63% grade I, 31% grade II, 6% grade III; scrotal: 41% grade I, 38% grade II, 21% grade III) and Kiupel (preputial: 91% low-grade, 9% high-grade; scrotal: 79% low-grade, 21% high-grade). Histological evaluation of superficial inguinal lymph nodes was performed in 55% of cases (50 dogs); of these, 16% (8/50) showed HN3 metastases. The overall median survival time was not reached and the 1-, 3- and 5-year survival rates were 85%, 67%, and 60%, respectively. On multivariable analysis, Kiupel high-grade and tumor diameter of at least 2 cm were associated with a shorter overall survival time, while HN3 lymph node metastases, aberrant KIT staining pattern, and Ki-67 index >23 were not. This data does not provide evidence of an inherently high biologic aggressiveness of preputial and scrotal MCTs. In the absence of other negative prognostic factors, dogs with preputial and scrotal MCTs have a favorable prognosis.

犬生殖道肥大细胞瘤（MCTs）的预后通常较差，但目前尚无大规模研究专门针对该部位的肥大细胞瘤展开。本研究旨在回顾性描述包皮部与阴囊部皮肤肥大细胞瘤患犬的临床病理特征及转归，并将该研究结果与其他部位皮肤肥大细胞瘤的历史数据进行对比。本研究回顾了某单一机构2002年至2024年的病历资料，纳入了91只接受手术治疗（联合或不联合辅助治疗）且至少随访6个月的患犬，其中包皮部病例35例、阴囊部病例56例。肿瘤分别依据Patnaik分级系统（包皮部：63%为I级，31%为II级，6%为III级；阴囊部：41%为I级，38%为II级，21%为III级）与Kiupel分级系统（包皮部：91%为低级别，9%为高级别；阴囊部：79%为低级别，21%为高级别）进行分级。对55%的病例（共50只犬）进行了腹股沟浅淋巴结的组织学评估，其中16%（8/50）检出HN3转移。整体中位生存期未达到，1年、3年及5年生存率分别为85%、67%与60%。多变量分析结果显示，Kiupel高级别肿瘤及肿瘤直径≥2 cm与更短的总生存期相关，而HN3淋巴结转移、异常KIT染色模式及Ki-67指数＞23则无此关联。本研究数据并未表明包皮部与阴囊部肥大细胞瘤本身具有较高的生物学侵袭性。在不存在其他不良预后因素的情况下，包皮部与阴囊部肥大细胞瘤患犬的预后较好。