Cutaneous malignant melanoma in a Haller’s round ray Urobatis halleri

Abstract

Multiple black raised nodular masses were noted on the dorsal surface of an adult male Haller's round ray Urobatis halleri. Biopsy of 2 masses was performed, and histopathology revealed proliferative sheets of melanocytes exhibiting mild anisocytosis and anisokaryosis, supporting a diagnosis of malignant melanoma. Approximately 2 mo following the biopsy procedure, the round ray became acutely anorexic and was found dead in its enclosure. A full necropsy was performed, and tissues were submitted for histopathology. The black raised nodular masses again exhibited histologic features of a melanoma. In addition to the nodular masses present, multiple flat areas of increased pigmentation were also present throughout the course of the case and were not suggestive of neoplasia histologically. The transformation of benign to malignant neoplasia has been well described in other species and may have played a role in the development of multiple tumors in this case.

Disseminated lymphoid neoplasia and hepatoblastoma in an Atlantic stingray, Hypanus sabinus (Lesueur 1824)

“…In contrast, a review of submissions to the Registry of Tumors in Lower Animals (RTLA) identified 42 neoplasms in various elasmobranchs (Ostrander, Cheng, Wolf, & Wolfe, ). Neoplasms reported in stingray species have included a presumptive dysgerminoma, renal fibroma, adenoma of the corpuscle of Stannius, hepatic adenoma, round cell tumour of the spleen, melanocytic nevus, cutaneous malignant melanoma, cutaneous soft tissue sarcoma, cutaneous papilloma/carcinoma‐in‐situ, and a subcutaneous fibrous hemangioma (Garner, ; Jafarey, Berlinski, Hanley, Garner, & Kiupel, ; Nau et al, ; Ostrander et al, ; Stidworthy, Thorton, & James, ). In this report, a case of disseminated lymphoid neoplasia and hepatoblastoma is described in a batoid species, the Atlantic stingray, Hypanus sabinus (Lesueur 1824).…”

Multiple recurrent cutaneous masses in a cownose ray (Rhinoptera bonasus) with progression from benign lesions to high‐grade carcinoma

“…A range of benign and malignant tumours, including round cell, mesenchymal and epithelial neoplasms, have been previously reported in elasmobranchs (Camus, Ibrahiem, Alhizab, Aboellail, & Ibrahim, ; Culp, Haulena, Britt, Evans, & Raverty, ; Garner, ; Nau et al, ; Ostrander, Cheng, Wolf, & Wolfe, ; Stidworthy, Thornton, & James, ; Stoskopf, ). Reports of cutaneous neoplasia have included soft tissue sarcoma of the skin of a cownose ray, cutaneous carcinoma in a thornback skate ( Raja clavata ), soft tissue sarcoma in an Arabian carpet shark ( Chiloscyllium arabicum ) and malignant melanoma in a Haller's round ray ( Urobatis halleri ) (Camus et al, ; Culp et al, ; Nau et al, ; Stidworthy et al, ). The current case is unique in that multiple types of skin tumours were present in a single animal and there was potential internal metastasis of cutaneous carcinoma, which has not been previously documented in elasmobranchs.…”