Cutaneous metastatic melanoma in a Siberian tiger (Panthera tigris altaica) - case report

Abstract

A male 15-year-old captive Siberian tiger (Panthera tigris altaica) developed pelvic limb hypermetry over the past 10 years. Recently, an ulcerated black nodule located caudally to the right ear was observed. The animal was submitted to surgery for removing the tumor, but died during anesthetic recovery. At necropsy, another infiltrative nodule was observed caudally to the right ear. Histologically, both nodules corresponded to melanocytic neoplasia, varying from heavily pigmented to amelanotic, with metastasis to mediastinal lymph nodes, spleen and lung. Lipofuscinosis and corpora amylacea were histologically observed in the central nervous system. Macroscopic and histologic findings confirmed the diagnosis of skin metastatic melanoma in a captive adult Siberian tiger.

Metastatic Cutaneous Melanoma in a White African Lioness (Panthera leo)

“…In domestic cats, intraocular melanoma and melanomas arising in the oral cavity, lips, and nose are associated with higher metastatic potential and/or decreased survival time, relative to cutaneous melanomas (of the skin or digit) [ 3 , 9 ]. However, in the present report of cutaneous melanoma, a high mitotic index, as well as a high degree of cellular and nuclear pleomorphism and metastasis were observed, similar to that reported for metastatic cutaneous melanoma in a Siberian tiger ( Panthera tigris altaica ) [ 7 ]. Interestingly, a mitotic index has been demonstrated to be a predictive prognostic factor for melanocytic neoplasia in domestic cats and dogs [ 10 ].…”

“…Of the non-ocular melanomas, a retrospective study of 23 cases found that the most common locations were the nose, digit, and pinna [ 4 ]. Melanomas are rare in non-domesticated felids, with only three reports to date [ 5 , 6 , 7 ], and only two involving lions: in the eye of a captive African lioness and on the maxillary lip of a captive African lion. The 19-year-old lioness with intraocular melanoma had concurrent mammary mucinous carcinoma and both tumours had widely metastasized upon presentation, so the lioness was euthanized two months later due to her deteriorating condition [ 5 ].…”

“…Six months after diagnosis, there were no signs of clinical disease or evidence of metastasis [ 6 ]. An aggressive cutaneous melanoma in a non-domesticated felid was recently reported in a 15-year-old captive Siberian tiger ( Panthera tigris altaica ), which developed an ulcerated black nodule caudally to the right ear [ 7 ]. The present report describes a cutaneous malignant melanoma on the ear of a white African lioness that was diagnosed due to its metastasis to the liver and omentum, resulting in the development of ascites and necessitating euthanasia due to her deteriorating clinical condition.…”

Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report

“…Multiple neoplasms are commonly observed in domestic dogs, especially with advanced age (Komsta & Łopuszyński, 2008;Priester, 1977). In captive wild animals, neoplasms are frequently reported and are believed to be related to senility (Oliveira et al, 2018;Carvalho et al, 2018;Eckstein et al, 2020). Beside the cutaneous tumor, the same individual presented multiple primary different neoplasms, such as an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.…”