Clinical course and pathologic study of retrobulbar histiocytic sarcoma in a central bearded dragon (<i>Pogona vitticeps</i>)

Abstract

A central bearded dragon ( Pogona vitticeps ) presented with periorbital swelling and exophthalmos. A retrobulbar mass was detected, and enucleation with the mass was performed. Histologically, the mass was composed of a dense sheet and interlacing bundles of round to polygonal to short spindle-shaped cells with occasional bizarre mononuclear and multinucleated giant cells. Immunohistochemically, the neoplastic cells had various degrees of membranous and/or cytoplasmic granular reactivity to anti-ionized calcium-binding adapter molecule 1 and anti-CD204 antibodies. Ultrastructurally, the neoplastic cells had irregular nuclei and abundant cytoplasm with membrane-bound electron-dense lysosomes and endoplasmic reticula. These findings were consistent with a histiocytic sarcoma. The present study provided a detailed description of retrobulbar histiocytic sarcoma for the first time in a central bearded dragon.

Disseminated histiocytic sarcoma in a degu (<i>Octodon degus</i>)

“…Histiocytic sarcoma has been reported in various mammalian, avian, and reptilian species [ 1 , 2 , 3 , 4 , 7 , 8 , 9 , 10 , 12 , 13 ]. The histological appearances of histiocytic sarcomas are variable and generally classified into two phenotypic subtypes: spindle cell type and round-polygonal cell type [ 1 , 8 ].…”

“…To differentiate histiocytic sarcoma from these tumors, immunohistochemical staining using histiocytic markers such as Iba-1, CD204, HLA-DR, and CD163 is helpful [ 9 , 10 ]. Similarly in exotic pet medicine, the immunohistochemical markers have been used to diagnose histiocytic sarcomas in four-toed hedgehogs, a chinchilla, a central bearded dragon [ 2 , 3 , 8 ]. Poorly differentiated sarcoma and anaplastic sarcoma with giant cells in degus were immunonegative for Iba-1 [ 12 ].…”