Case Information:

Necropsy Date:	12/14/23 & 12/15/23	Clinician:	Keller
IVAC Service ID:	23-3234	Prosector:	Boulanger
Species:	Leopard Gecko	Gross necropsy pathologist:	Lee
Principal Investigator:	Guo	Other contact:
Depart:

Animal ID:

Animal ID:	Clinical Number:	Age:	Sex:	Genotype/Strain/Study:	Mode of Death:
Gecko A	23x10670	~ 7 mo	female	Super Lemon Frost Morphology	Euthanized-Injectable
Gecko B	23x10671	~ 7 mo	female	Super Lemon Frost Morphology	Euthanized-Injectable

Clinical History:

Both Geckos demonstrated intermittent anorexia to hyporexia with intermittent lethargy. Gecko A demonstrated multiple developing masses with ultrasonographic evidence of multi-organ involvement. FNA of submandibular mass potentially indicative of iridophoroma. Gecko A also demonstrated significant decline in body conditioning. Gecko B demonstrated similar signs to a mild degree.

Final Diagnos(es) for Case

Organ/System	Process	Diagnosis
Hepatic	Nutritional	Gecko B: Hepatic lipidosis
Integument	Neoplastic	Iridophoroma (both gecko A and B), with metastasis (only in gecko A) in liver, lung, and ovary
Reproductive	Nutritional	Ovarian cyst, oophoritis, egg yolk stasis, ovary (gecko A and B), and coelomitis (gecko B)

Final Comments:

Iridophoroma in gecko A appeared to metastasize to multiple organs in gecko A, but such metastasis was not evident in gecko B. Moreover, histology confirmed that another main finding grossly, which was an ovarian mass or enlarged ovaries in both cases, was granulomatous oophoritis very likely due to preovulatory follicular stasis (POFS). POFS was not uncommon in captive reptiles. The cause of POFS is poorly understood (Kophamel-Orduna et al., 2018). Nutritional imbalance has been speculated as one of the causes for POFS in the literature. In our case, the animals were fed with a varied and appropriate diet, although hyporexia/anorexia may have played a role in developing the disease. In gecko B, the severe oophoritis extended to the coelom, causing coelomitis and the adherence with the distal portion of the liver. The focally extensive granulomatous hepatitis is thus believed to be an extent of oophoritis and coelomitis. No overt evidence of infectious etiology was found in the granulomatous inflammation (Gram and acid fast stains showed no bacteria). Culture of the ovarian mass from one of the geckos yielded no growth of bacteria. Gecko B also had hepatic lipidosis, which is also another common pathology in captive reptiles. Ref: Kophamel-Orduna S, Lebens M, Gunther CP, Wohlsein P, Puff C, Fehr M, et al. Lipogranulomatous Oophoritis in a Leach's giant gecko (Rhacodactylus leachianus). Wiener Tieraerztliche Monatsschrift Veterinary Medicine Austria. 2018;105(3/4 (3)):73–80.

Pathologist Only:

Case Complete?	Yes
Final Review Pathologist:	Yao Lee, DVM, MS, PhD, DACVP
Completion Date:	2024-01-04

Gross Findings

	Gecko A	Gecko B
Body condition score:	2/5	3/5
Carcass condition:	Intact	Intact
Autolysis:	None	None

Gross Lesions

Organ System	Evaluated? (Y/N/Some animals)	Findings or Comments Y/N	Comments (only if Findings)
Cardiovascular	Y	Y	Gecko A: Thoracic portion of caudal vena cava distended.
Endocrine	Y	N
Gastrointestinal	Y	Y	Gecko A: caudal left sided coelomic distension noted grossly on dorsum. Ventrum demonstrated visible mass in caudal left abdomen. Stomach did not contain ingesta, and gastrointestinal tract lacked fecal material. Abdomen was distended with clear fluid. Gecko B: food contents in stomach with appropriate digesta present in gastrointestinal tract.
Hematolymphoid	Y	N
Hepatic	Y	Y	Gecko A: multifocal disseminated raised, well demarcated white masses, bulge on cut section, throughout all liver lobes. Gallbladder appears enlarged. Gecko B: diffuse pale discoloration with white raised lesions in caudal left lobe. Hepatomegaly with rough surface, covered by some friable membranous material (fibrin or necrotic debris). The distal part of the liver was firmly adhered with one side of the ovary. Gallbladder size was unremarkable.
Integument	Y	Y	Geck A: right-sided subcutaneous mass at the mandible, freely-movable, marked, unilateral. Gecko B: right-sided subcutaneous mass, freely-movable, mild, unilateral. Focal depression on caudal right flank, with white plaque between skin and underlying muscle.
Multisystemic	Y	Y	Gecko A: white plaques, multifocal to coalescing, noted throughout the body cavities , the oral cavity, within the mediastinum, and on the majority of serosal surfaces.
Musculoskeletal	Y	N
Nervous	Y	N
Oral Cavity	Y	Y	Gecko A: bilateral white plaques noted on surface of the caudal oral cavity, appearing to originate near the angle of the mandible
Reproductive	Y	Y	Gecko A: large, well-vascularized mass appeared to originate from the left ovary filling entire length of abdomen (approx 3.5 inches in length), white to tan heterogenous coloration with firm cranial pole and fluid-filled caudal pole. The enlarged left ovary contained a large amount of yellow to white friable material (necrotic debris). Both ovaries demonstrated active follicles. Gecko B: bilateral enlarged ovaries, tan to hemorrhagic with foci of necrosis, potentially associated with reproductive tract with adhesive multifocal white plaque on mucosal surface. Both ovaries are soft and contained copious mucinous yellow to white friable material. Ovaries appear to have been ovulating.
Respiratory	Y	N
Urinary	Y	N

Additional Procedures Performed: Check all that apply

Culture, ovary mass swab	No bacterial growth
Cytology	Direct smear of ovarian mass and liver, Diff Quick: Numerous melanomacrophages and macrophage-like round cells with foamy cytoplasm and birefringent granules. The cytology of the ovarian mass also showed abundant fatty droplets or adipocytes in the background. No apparent infectious agents were found.

Microscopic Findings

Organ/Slide	Findings Y/N	Description
Brain	N
Heart	N
Kidneys	N
Liver	Y	Gecko A: Multiple foci of brown, birefringent, neoplastic clusters in the parenchyma. These cells are pleomorphic, round to elongated, and has birefringent intracytoplasmic granules. Gecko B: >90% of parenchyma has vacuolated hepatocytes (fatty change and glycogen accumulation). The distal part of the liver that is partially adhered with the ovary has a demarcated, encapsulated nodule showing severe loss of hepatocytes with degeneration, fatty change, infiltration of numerous multinucleated giant cells (with intracytoplasmic lipofuscin-like material), macrophages, and very few lymphocytic inflammatory cells. Gram and acid fast blue stains showed no bacteria.
Lungs	Y	Gecko A: Brown tumor emboli in the septum. Gecko B: Serosa has multiple plump vacuolated cells and some hypereosinophilic droplets (egg yolk material).
Ovaries	Y	Gecko A: The ovary mass is a single extremely large ovarian follicle filled with degenerative egg yolk material and necrotic debris, surrounded by disorganized thecal cells with vacuolated change mixed with infiltration of macrophages and fibrosis. Multifocally, the capsule of the ovary and serosa are invaded by clusters of spindoloid cells with faded brown pigments (metastatic tumor). Gecko B: Both sides of the ovary have one extremely large ovarian follicle filled with degenerative egg yolk material and necrotic debris, surrounded by disorganized thecal cells mixed with infiltration of multinucleated giant cells, macrophages, and fibrosis. Serosa and coelomic tissue have lots of cells showing vacuolated degeneration, with infiltration of macrophages, hemorrhage, admixed with abundant hypereosinophilic hyaline droplets (egg yolk material).
Skin mass, multiple	Y	Gecko A and B: The dermis and subcutis are expended by multifocal to coalescing, well demarcated, nonencapsulated, light brown masses. These masses have spindoloid neoplastic cells characterized by abundant cytoplasm with light brown, birefringent pigments, small oval nucleus, and indistinct nucleolus. Anisokaryosis and anisocytosis are marked. Mitotic figures are frequent at high power field.
Skull	Y	Metastatic tumor found at the skin of the skull, as well as at the oral cavity.
Spleen	N
Stomach and colon	N

Microscopic Morphologic Diagnos(es)

Organ/System	Process	Morphologic Diagnosis
Liver	Nutritional	Hepatitis, granulomatous, focally extensive, chronic, with moderate to severe hepatic lipidosis (gecko B)
Ovary	Nutritional	Ovarian cyst, and oophoritis, severe, focally extensive, chronic, lipogranulomatous, with egg yolk stasis (gecko A and B)
Skin, multiple area	Neoplastic	Iridophoroma, malignant, multicentric (gecko A and B), with metastasis in liver, lung, and ovary (only in gecko A)