Metastatic squamous cell carcinoma in two loggerhead sea turtles Caretta caretta

Abstract

We received 2 stranded loggerhead sea turtles (Caretta caretta) with squamous cell carcinomas to necropsy. The dead turtles had been collected in Gran Canaria and Fuerteventura in April 1994 and May 1997, respectively to determine the cause of death. One turtle had 3 ulcerated lesions in the dorsal part of the neck and several irregular masses in the lungs and kidneys. Histologic examination of lesions in the skin, lungs, kidneys, and ventricular myocardium revealed neoplastic proliferation of abnormal keratinocytes. Ultrastructural examination identified the tumoral cells as epithelial cells. The second turtle had 4 lesions in the skin of the head and flippers, and several irregular masses in the lungs, liver, and kidneys. Histological examination revealed a squamous cell carcinoma with metastases to muscle tissue, liver, lungs, and kidneys. Attempts to characterize the tumoral cells by immunohistochemistry using several monoclonal and polyclonal antisera against high and low molecular weight cytokeratins from mammals, as well as vimentin and desmin, failed. Differences between reptilian keratins (mainly β-keratins) and mammalian keratins (mainly α-keratins) could explain this absence of immunoreactivity. This is the first description of squamous cell carcinoma in sea turtles. KEY WORDS: Squamous cell carcinoma · Loggerhead turtle · Caretta caretta · Sea turtle · Reptile · Immunohistochemistry Resale or republication not permitted without written consent of the publisherDis Aquat Org 58: [245][246][247][248][249][250] 2004 of 20 to 30 turtles per year. We report here the histopathological features of 2 cases of metastasizing squamous cell carcinoma in the loggerhead sea turtle Caretta caretta. MATERIALS AND METHODSWithin a 3 yr period (i.e. in April 1994 and May 1997), 2 stranded loggerhead sea turtles with squamous cell carcinomas were submitted to the Veterinary Faculty, ULPGC. The first was a 6.5 kg juvenile female stranded in Gran Canaria (27°40' N, 15°20' W). The turtle had a curved carapace length and width of 33 and 31 cm respectively, and a straight carapace length and width of 29 and 28 cm respectively. After stranding, the turtle had been housed in an aquarium at the Wildlife Rehabilitation Center of Tafira, Gran Canaria. Physical examination had revealed anorexia and lethargy. Despite forcefeeding and intramuscular administration of antimicrobial enrofloxacin, the turtle died 1 wk after stranding. The second turtle was a 7.2 kg juvenile female found stranded dead in Fuerteventura (28°10' N, 14°20' W). This turtle had a curved carapace length and width of 34 and 33 cm respectively, and a straight carapace length and width of 31 and of 30 cm respectively.The gross postmortem examinations of both turtles were carried out using the protocol developed by Wolke & George (1981). Fecal specimens were processed following techniques described by Boch & Supperer (1982).Macroscopic lesions were recorded and tissue samples from all major organs were fixed in 10% neutral buffered formalin, embedded i...

Non-metastatic squamous cell carcinoma in two Hermann’s tortoises (Testudo hermanni)

“…Metastatic spread of SCC in reptiles is rare and has been reported in only three cases of turtles. 7,9 Humoral hypercalcemia of malignancy (HHM) is a paraneoplastic syndrome commonly associated with several mammalian tumors but to the authors knowledge it has not been described in reptiles. HHM is caused by de novo secretion of parathyroid hormone-related protein (PTHrP) by the tumor cells or thought to be associated with tumor induced osteolysis.…”

“…5,6 Within the order of testudines several cases of SCC have been described in turtles. 2,[7][8][9][10][11] However, in the family testudinidae (tortoises) only two cases of SCC has been reported so far, in a Brazilian giant tortoise (Chelonoidis denticulata, formerly Geochelone denticulata) 12 and in a Hermann's tortoise. 13 The skin is the most common site to develop SCC in chelonians but oral, 6,12 and coelomic 8 SCC can also be present.…”

Harderian gland adenocarcinoma in a Florida Red-bellied Turtle ( Pseudemys Nelsoni ) — Case report

“…Attempts to characterise the tumour immunohistochemically have failed, as no positive colour reaction could be detected. This result can be explained by the fact that cells of reptile origin do not react to antibodies routinely used in the identification process of human cells, as previously reported (Orós et al, 2004). Due to the fact that the slides stained with HE were self-explanatory and the pathological process could be easily identified, the negative results of the IHC investigations did not interfere with the diagnostic process.…”

Oral fibrosarcoma in jararaca (Bothrops pubescens): anatomopathological and immunohistochemical aspects

“…Its occurrence, in our case, can be explained by the location of the nodule, given that the lump protruded out of the oral cavity, suffering all kinds of friction. Recent studies have found high recurrent and metastatic potential of this neoplasm in snakes and other reptiles (Ramis et al 1998, Orós et al 2004, Hes et al 2007, Orós et al 2009, Salinas et al 2013, Sharpe et al 2013). In our case there was recurrence of fibrosarcoma in about 60 days after surgical removal of the primary nodule.…”

“…However, recent studies have found high recurrent and metastatic behavior of this and other neoplasms in snakes and other reptiles (Ramis et al 1998, Orós et al 2004, Hes et al 2007, Orós et al 2009, Salinas et al 2013, Sharpe et al 2013). On clinical examination, the fibrosarcomas are presented as small or large nodular mass and soft to firm consistency, which impair biological functions of some snakes such as swallowing.…”