School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Australian Centre for Disease Preparedness (ACDP), Commonwealth Scientific and Industrial Research Organisation (CSIRO), East Geelong, Victoria, Australia.
Aust Vet J. 2022 Jun;100(6):271-276. doi: 10.1111/avj.13157. Epub 2022 Mar 8.
Neoplasia is considered to be rare in macropods. Anaplastic thyroid carcinoma (ATC) also known as undifferentiated or giant cell carcinoma, is a rare but aggressive and lethal solid tumour reported to affect humans, dogs, cats, racoons and birds. It is derived from poorly differentiated follicular cells and lacks the characteristic architectural pattern of arrangement of tumour cells. ATC has not previously been reported in macropods.
A brush-tailed rock-wallaby (Petrogale penicillata) was presented for a mass on the ventral neck. A clinical diagnosis of thyroid carcinoma was suspected based on radiology, ultrasound and cytology. Other than palliative care, treatment was declined. Four months later the wallaby was found dead and submitted for necropsy. Gross examination and histopathology demonstrated a unilateral ATC with vascular neoplastic emboli and distant metastases to the heart, lungs and liver.
The clinical signs associated with thyroid tumours may be the result of localised growth and expansion of the thyroid, metastatic disease or a combination of these effects. Most thyroid tumours are nonfunctional. Based on the lack of typical clinical signs associated with functional thyroid tumours, in this case, we conclude that the thyroid tumour in this wallaby was likely to be nonfunctional. The cause of death in this wallaby was likely due to the heavy tumour burden with compromised cardiorespiratory function exacerbated by dorsoventral compression of the larynx. More study is needed to better understand thyroid neoplasia in macropods.
人们认为有袋类动物的肿瘤比较少见。间变性甲状腺癌（ATC）又称未分化或巨细胞癌，是一种罕见但具有侵袭性和致命性的实体肿瘤，据报道可影响人类、狗、猫、浣熊和鸟类。它来源于分化不良的滤泡细胞，缺乏肿瘤细胞排列的特征性结构模式。在有袋类动物中，ATC 以前尚未被报道过。
一只帚尾岩袋鼠（Petrogale penicillata）因颈部腹侧有肿块而就诊。基于影像学、超声和细胞学检查，临床怀疑为甲状腺癌。除了姑息治疗外，治疗被拒绝。四个月后，这只岩袋鼠被发现死亡并进行了尸检。大体检查和组织病理学显示为单侧 ATC，伴血管肿瘤栓子和远处转移到心脏、肺和肝脏。
与甲状腺肿瘤相关的临床症状可能是甲状腺局部生长和扩张、转移疾病或这些影响的综合结果。大多数甲状腺肿瘤是无功能性的。基于与功能性甲状腺肿瘤相关的典型临床症状缺乏，在这种情况下，我们推断这只岩袋鼠的甲状腺肿瘤可能是无功能性的。这只岩袋鼠的死因可能是由于肿瘤负荷过重，导致心肺功能受损，加上喉的背腹侧受压而恶化。需要进一步研究以更好地了解有袋类动物的甲状腺肿瘤。
