Sheppard Barbara J, McGrath Elizabeth, Giuffrida Michelle, Craft Serena L M, Kung Chung Yee, Smith Matthew E
1Barbara J. Sheppard, Department of Infectious Diseases and Pathology, University of Florida, Gainesville, FL 32611.
J Vet Diagn Invest. 2013 Sep;25(5):566-72. doi: 10.1177/1040638713499341. Epub 2013 Aug 8.
A 75.9-kg, 3.5-year-old male Irish Wolfhound dog with a 2-3-week history of gagging and eating difficulties was referred to the University of Florida Veterinary Medical Hospital (Gainesville, Florida) for evaluation of a large cranial mediastinal mass suspected to be a thymoma or lymphosarcoma. The patient had 4 months of nearly 10 kg progressive weight loss with severe flank sensitivity and radiographically apparent lumbar vertebral changes interpreted as discospondylitis. Lab work revealed hyperglobulinemia, mild proteinuria, normal T4, negative Brucella canis titer, and negative blood and urine bacterial cultures. A thoracotomy revealed a nonresectable, destructive, space-occupying mediastinal mass resulting in euthanasia without surgical recovery. Biopsies from the mass were collected during surgery for histology. Microscopic examination revealed extensive granulomatous cellulitis and lymphadenitis characterized by central cavitated necrotic areas containing debris and degenerate neutrophils, intermediate zones of fibrovascular proliferation with marked mixed inflammation, peripheral fibrosis, frequent multinucleated macrophages, and scattered mineralization. The necrotic material contained dense mats of 2 µm wide by 8-15 µm long fungal hyphae with parallel walls, acute angle branching, frequent septae, and occasional bulb-like dilations. DNA sequencing and phylogenetic analysis of the internal transcribed spacer region confirmed the presence of a fungus in the Inonotus tropicalis group. Inonotus tropicalis is primarily a wood decay fungus that is found on dead wood from angiosperms in tropical and subtropical habitats. Isolates of the I. tropicalis group have been detected a few times from immunosuppressed human beings with X-linked granulomatous disease.
一只75.9千克、3.5岁的雄性爱尔兰猎狼犬，有2至3周的作呕和进食困难病史，被转诊至佛罗里达大学兽医学院医院（佛罗里达州盖恩斯维尔），以评估一个怀疑为胸腺瘤或淋巴肉瘤的巨大纵隔肿块。该患者在4个月内体重渐进性减轻近10千克，伴有严重的胁腹敏感，影像学检查显示腰椎有明显变化，诊断为椎间盘脊柱炎。实验室检查发现有高球蛋白血症、轻度蛋白尿、T4正常、犬布鲁氏菌滴度阴性，血液和尿液细菌培养阴性。开胸手术发现一个无法切除的、破坏性的纵隔占位性肿块，导致实施安乐死，手术未能恢复。手术期间从肿块处采集活检组织进行组织学检查。显微镜检查显示广泛的肉芽肿性蜂窝织炎和淋巴结炎，其特征为中央有空洞的坏死区域，含有碎片和变性中性粒细胞，中间为纤维血管增生并伴有明显混合性炎症的区域，外周纤维化，常见多核巨噬细胞，并有散在矿化。坏死物质中含有密集的菌丝垫，菌丝宽2微米，长8至15微米，壁平行，呈锐角分支，有频繁的隔膜，偶尔有球状扩张。对内部转录间隔区进行DNA测序和系统发育分析，证实存在热带纤孔菌属的一种真菌。热带纤孔菌主要是一种木材腐朽真菌，见于热带和亚热带栖息地被子植物的枯木上。热带纤孔菌属的分离株曾在少数患有X连锁肉芽肿病的免疫抑制患者中被检测到。
