Liposarcoma of the Fat Body in a Bearded Dragon (Pogona vitticeps)
An 8-yr-old male bearded dragon (Pogona vitticeps) presented with lethargy, inappetence, and skin discoloration. Dorsoventral whole body radiographs revealed a homogenous left coelomic mass. A complete blood count revealed leukocytosis and monocytosis, while the plasma biochemistry revealed hypercalcemia, elevated lactate, and elevated creatinine. Coelomic ultrasonography was performed to further characterize the mass before surgical exploration and removal. Ultrasonography revealed a hyperechoic mass that was vascular with a hypoechoic, avascular center consistent with fluid accumulation. An exploratory coeliotomy was performed and the left fat body containing the mass was removed en bloc for histopathologic evaluation. Oil Red O staining confirmed a diagnosis of liposarcoma. Continued decline after discharge prompted a decision to euthanize the patient. Unfortunately, a necropsy was not elected.Abstract
Dorsoventral radiograph, 8-yr-old bearded dragon. In the left caudal coelom, there is a mass (arrows) of soft tissue opacity.
Ultrasonography, coelom of the same patient. Cranial is to the left, and A is cranial to B. In the left hemicoelom, the liposarcoma (white arrow) is mildly hyperechoic and subtly heterogeneous, with a central hypoechoic zone (black arrows) later confirmed to represent fat necrosis. Cranial and dorsal to the liposarcoma, the fat body has a similar echotexture; margins between the two are indistinct. In A, at the cranial edge of the liposarcoma there is a 6.4-mm nodule (calipers) isoechoic to the fat body, with a thin hyperechoic rim. In B, dorsal to the mass is a normal testicle (calipers).
Intraoperative photograph with the fat body exposed and the patient facing toward the left and bottom of the image. The fat body is distorted, and in its caudal aspect there is a large fatty nodule (black arrows). In the interface between this nodule and normal fat body tissue, there is a broad zone of necrosis (white arrows).
Neoplasm in the fat pad composed of interlacing bundles of spindle cells (S) with variably sized cytoplasmic vacuoles and marked anisokaryosis and nuclear pleomorphic. Large vacuoles of pre-existing fat (F) are present and coagulative necrosis (N) is extensive. H&E stain. Inset: The cytoplasm of tumor cells contains red lipid globules on Oil Red O staining.
