Dasyurids

The most significant neoplasm of dasyurids is devil facial tumour disease (DFTD) of Tasmanian devils, which is covered in depth in Chapter 40.

Dasyurids are also highly susceptible to other neo­plastic disease, with a reported incidence at necropsy of 46% (Ladds 2009).

Fig. 18.2. Craniofacial osteochondroma in an 8-yr-old male koala (Phascolarctos cinereus), with orbital involvement. (a) Clinical presentation with firm swelling of the right temporo-zygomatic region of the face. (b) Volume-rendered three-dimensional CT reconstruction showing an irregular osseous mass arising from the right zygomatic arch, with new bone impinging slightly on the lateral aspect of the right temporomandibular joint. (c) Prepared skull with a multinodular bony mass involving the right temporo­zygomatic bones, including invasion into the right orbit.

Table 18.4. Benign neoplasms reported in koalas (Phascolarctos cinereus)

Adenoma: biliary;^1a pituitary (chromophobe);^1b sebaceous (n = 2)^2,3

Adenomatosis: subcutaneous⁴

Fibroadenoma: cutaneous^1c

Fibroleiomyoma: uterine^1d

Leiomyoma: intestinal;^1e urinary bladder;⁵ uterine⁶

Myxofibroma: subcutaneous (transponder-associated)⁷

Papilloma: oral^1f

Rhabdomyoma: skeletal muscle⁸

Spindle-cell tumour: nasal⁹

¹ARWH 2018 case nos ^a7101.1; ^b3267.1; ^c10821.1; ^d3267.1; ^e3791.1; ^f4583.1; ²Blanshard and Bodley 2008; ³Antonsson and McMillan 2006; ⁴Hanger and Loader 2014; ⁵Stadler etal.

(carcinoma-in-situ) (Tables 18.6 and 18.7). Malignant neoplasms included SCCs (n = 48), lymphosarcoma (n = 34) and adenocarcinomas of various types (n = 31). Spin­dle cell malignancies were comparatively infrequent (n = 26). Hepatoma (n = 12) and trichoepithelioma (n = 7) were the most frequently reported benign neoplasms.

It is not uncommon for dasyurids, particularly aged Tasmanian devils, to present clinically or at necropsy

Table 18.5. Malignant neoplasms in koalas (Phascolarctos cinereus)

Adenocarcinoma: biliary;¹ genitourinary tract;² hepatic;^3,10 intestinal;⁴ mammary;⁶ pancreatic duct;⁷ urinary bladder;⁸ colonic¹⁰

Carcinoma: bronchoalveolar¹⁰

Fibrosarcoma: oral (multiple)^5b; sternal³

Giant cell tumour: periosseous⁴

Granulosa-cell tumour: ovarian^5c

Haemangiosarcoma: splenic;² unknown primary (n = 2)⁴

Leiomyosarcoma: hepatosplenic^5c

Liposarcoma: ovarian (rhabdomyosarcomatous type)^5d

Mast cell leukaemia¹²

Nephroblastoma⁴

Osteosarcoma: long bone⁹

Phaechromocytoma⁴

Squamous cell carcinoma: nictitating membrane;² cutaneous;^5e glossal;^5f digit;¹¹ location unspecified¹⁰

Teratoma: testicular³

¹Canfield et al. 1987a; ²Blanshard and Bodley 2008; ³Canfield et al. 1990b; ⁴Gillett 2014; ⁵ARWH 2018 case nos ^a6794.1; ^b29.2; ^c11385.1; ^d11405.1; ^e3089.2; ^f8311.1; ⁶Hanger and Loader 2014; ⁷Higgins and Canfield 2009; ⁸Ladds 2009; ⁹Worley etal. 1993; ¹⁰Gonzalez-Astudillo etal. 2019; ¹¹Kobayashi etal. 2021; ¹²Phillips etal. 2020

with multiple neoplasms (Canfield and Cunningham 1993; Holz 2008; Michael and Sangster 2010; ARWH 2018; Peck et al. 2019). Examples of polyneoplastic disease in Tasmanian devils include: an animal with malignant phaeochromocytoma, thyroid adenoma and hepatoma (Michael and Sangster 2010); an animal with multicentric lymphosarcoma, haemangiosarcoma, metastatic SCC and jejunal leiomyoma (ARWH 2018 case no. 7901.3); and an animal with perineal SCC, dermal sarcoma and a subcu­taneous lipoma (ARWH 2018 case no. 7744.2).

Multiple cases of successful surgical excision of cuta­neous and mammary neoplasms in the Tasmanian devil have been reported (sections 1.1 and 1.2). In another case, a costal chondrosarcoma was excised in a 3.5-yr-old female, which had not recurred by the time of her death aged 8 yr (ARWH 2018 case no. 12161).

4.